Hewlett-Packard HP 8752 C, HP 8563 E, HP 5343 A, HP 8902 A, HP 436 A, HP 437 A, HP 438 A, HP 8482 A, HP 8481 A, HP 8483 A, HP 86032 B, HP 85036 B, HP 86029 B, HP 9135 -0198, HP 8496 A, HP 8491 A, HP 11667 A, HP 11862 B, 1250-1750, 1250-1745 User manual

1
Service Equipment and Analyzer Options
Table of Service Test Equipment
The following tables list the tools and test equipment required to perform the
analyzer’s system verification, troubleshooting, adjustment, and performance
tests.
Service Equipment and Analyzer Options
1-1
Table l-l. Service Test Equipment
Required
Equipment
Spectrum Analyzer
Critical
Specifications
Freq. Accuracy ±7 Hz
Recommended
Model
HP 8563E
4, T
Frequency Counter
HP 5343A
P
Measuring Receiver
HP 8902A
P
Oscilloscope
Bandwidth: 100 MHz
Accuracy: 10%
Digital Voltmeter
Resolution: 10 mV
any
T
Tool Kit
No substitute
HP part number
08763-60023
T
Power Meter (HP-IB)
No substitute
HP 436A Opt. 022,
HP 437A or 438A
Power Sensor
Frequency: 300 kHz-3 GHz, 50 ohms HP 84828
4, P, T
Power Sensor (for Option 006)
Frequency: 3 GHz-6 GHz
4, P, T
Power Sensor
Frequency: 300 kHz-3 GHz, 75 ohms HP 8483A Opt. HO3
T
HP 84818 Opt 006
P
Photometer
Tektronix J16
4
Photometer Probe
Tektronix J6503
4
Light Occluder
Tektronix
016-0306-00
4
CRT Demagnetizer or Bulk Tape
Eraser
4
Printer
HP ThinkJet,
DeskJet, LaserJet
3
Disk Drive
3.5-inch
HP 9122
Floppy Disk
3.5-inch
HP 92192A
Calibration Kit Type-N, 500
No substitute
HP 86032B
Calibration Kit Type-N, 760
No substitute
HP 85036B
Verification Kit 7 mm
No substitute
HP 86029B
Low Pass Filter
>50 dB @ 2.96 Hz and passband that
includes 800 MHz
HP P/N 9135-0198
Step Attenuator
10 dB
HP 8496A
Attenuators (fixed):
Return loss: > or = 32 dB APC-7 20 dB (2) HP 8491A Opt. 020
P, T
Power Splitter
1-Way, 40 ohms
HP 11667A
P, T
Minimum Loss Pad
Type-N, 50 ohms to 75 ohms
HP 11862B
P, T
1-2
Service Equipment and Analyzer Options
P
Table l-2. Service Test Equipment (2 of 2)
Required
Equipment
Critical
Specifications
Adapter
BNC to Alligator Clip
Adapter
APC-3.6 (m) to type-N (f)
HP P/N 1250-1750
A, P
Adapter
APC-3.5 (f) to type-N (f)
HP P/N 1250-1745
A, P
Adapter
APC-3.5 (f) to type-N (m)
HP P/N 1250-1744
A
Adapter
BNC (m) to type-N (f)
HP P/N 1250-0077
P
Adapter
type-N (m) to type-N (m)
HP P/N 1250-1528
P
RF Cable
24-inch, type-N, 75 ohms
HP P/NN8120-5639
A, P
RF Cable
24-inch, type-N, 50 ohms
HP P/N 8120-4781
A, P
RF Cable Set
type-N, 50 ohms
HP 11861B
P
HP 10833A/B/C/D
A
HP-IB Cable
Coax Cable
BNC
HP P/N 8120-1840
A
Coax Cable
BNC (m) to BNC (m), 50 ohms
HP 10503A
A
Antistatic Wrist Strap
HP P/N 9300-1367
A, T, P
Antistatic Wrist Strap Cord
HP P/N 9300-0980
A, T, P
Static-control Table Mat and
Earth Ground Wire
HP P/N 9300-0797
A, T, P
* P Performance Tests
A . Adjustment
T Troubleshooting
Service Equipment and Analyzer Options
1-3
Table l-2. Required Tools
T-8, T-10 and T-15 TORX screwdrivers
Flat-blade screwdrivers-small, medium, and large
5/16-inch open-end wrench (for SMA nuts)
3/16, 5/16, and 9/16-inch hex nut drivers
5/16-inch open-end torque wrench (set to 10 in-lb)
2.5-mm hex-key driver
Non-conductive and non-ferrous adjustment tool
Needle-nose pliers
Tweezers
Antistatic work mat with wrist-strap
1-4
Service Equipment and Analyzer Options
Principles of Microwave Connector Care
Proper connector care and connection techniques are critical for accurate,
repeatable measurements.
Refer to the calibration kit documentation for connector care information.
Prior to making connections to the network analyzer, carefully review the
information about inspecting, cleaning and gaging connectors.
Having good connector care and connection techniques extends the life of these
devices. In addition, you obtain the most accurate measurements.
This type of information is typically located in Chapter 3 of the calibration kit
manuals.
For additional connector care instruction, contact your local Hewlett-Packard
Sales and Service Office about course numbers HP 85050A + 24A and
HP 85050A + 24D.
See the following table for quick reference tips about connector care.
Service Equipment and Analyzer Options
1-5
Table l-3. Connector Care Quick Reference
Handling and Storage
Do Not
Do
Keep connectors clean
Touch mating-plane surfaces
Extend sleeve or connector nut
Set connectors contact-end down
Use plastic end-caps during storage
Visual Inspection
Do Not
Do
Inspect all connectors carefully
Use a damaged connector-ever
Look for metal particles, scratches, and dents
Connector Cleaning
Do
Do Not
Try compressed air first
Use any abrasives
Use isopropyl alcohol
Get liquid into plastic support beads
Clean connector threads
Gaging Connectors
Do
Do Not
Clean and zero the gage before use
Use an out-of-spec connector
Use the correct gage type
Use correct end of calibration block
Gage all connectors before first use
Making Connections
Do
1-6
Do Not
Align connectors carefully
Apply bending force to connection
Make preliminary connection lightly
Over tighten preliminary connection
Turn only the connector nut
Twist or screw any connection
Use a torque wrench for final connect
Tighten past torque wrench “break” point
Service Equipment and Analyzer Options
Analyzer Options Available
Option 003, 3 GHz Operation
This option extends the maximum source and receiver frequency of the analyzer
to 3 GHz.
Option 004, Step Attenuator
This option provides a source output power range from -85 to + 10 dBm.
Option 006, 6 GHz Operation
This option extends the maximum source and receiver frequency of the analyzer
to 6 GHz.
Option 010, Time Domain
This option displays the time domain response of a network by computing
the inverse Fourier transform of the frequency domain response. It shows
the response of a test device as a function of time or distance. Displaying the
reflection coefficient of a network versus time determines the magnitude and
location of each discontinuity. Displaying the transmission coefficient of a
network versus time determines the characteristics of individual transmission
paths. Time domain operation retains all accuracy inherent with the correction
that is active in such devices as SAW filters, SAW delay lines, RF cables, and RF
antennas.
Option 075, 75 ohm Impedance
This option offers 75 ohm impedance bridges with type-N test port connectors.
Option 1CM, Rack Mount Flange Kit Without Handles
This option is a rack mount kit containing a pair of flanges and the necessary
hardware to mount the instrument, with handles detached, in an equipment
rack with 482.6 mm (19 inches) horizontal spacing.
Service Equipment and Analyzer Options
1-7
Option 1CP, Rack Mount Flange Kit With Handles
This option is a rack mount kit containing a pair of flanges and the necessary
hardware to mount the instrument with handles attached in an equipment rack
with 482.6 mm (19 inches) spacing.
Option AFN, add 50 ohm Test Port Cable
This option provides a second type-N male to type-N male test port cable and a
type-N female to type-N female adapter. Instructions are included for storing a
new internal calibration to account for the effects of this cable.
Option AFP, add 75 ohm Test Port Cable
This option provides a 75 ohm type-N male to type-N female test port cable.
Instructions are included for storing a new internal calibration to account for
the effects of this cable.
Option B02, External Disk Drive
This option provides an external disk drive and an HP-IB cable.
1-8
Service Equipment and Analyzer Options
Service and Support Options
The analyzer automatically includes a one-year on-site service warranty, where
available. If on-site service is not available in your local area, you can purchase
the HP 8752C with a W08 option, which converts the one year on-site warranty
to a three year return to HP warranty. Consult your local Hewlett-Packard sales
engineer for on-site service.
The following service and support options are available at the time you
purchase an HP 8752C network analyzer.
Option W32
This option provides three years of return to HP calibration service.
Option W52
This option provides five years of return to HP calibration service.
Option W34
This option provides three years of return to HP Standards Compliant
Calibration.
Option W54
This option provides five years of return to HP Standards Compliant Calibration.
If support was not purchased along with the analyzer, there are many repair
and calibration options available from Hewlett-Packard’s support organization.
These options cover a range of on-site services and agreements with varying
response times as well as return to HP agreements and per-incident pricing.
Contact your local Hewlett-Packard customer engineer for details.
Service Equipment and Analyzer Options
1-9
3
Adjustments and Correction Constants
The accuracy of the analyzer is achieved and maintained through mechanical
adjustments and correction constants. The correction constants are empirically
derived data that is stored in memory. Correction constants refine the analyzer’s
measurements and define its operation.
When to Perform the Adjustment Procedures
Perform the following adjustment procedures in these two instances:
n
n
if one of the analyzer’s assemblies has been replaced
or
if one or more of the analyzer’s performance tests failed.
Keep Correction Constants Current to Save Time
Keep the correction constants current by performing “15. EEPROM Backup
Disk Procedure” any time you perform one or more of the correction constant
adjustment procedures. Then, if you need to replace the A9 assembly, you can
quickly retrieve the data from the back up disk, rather than regenerating it by
performing all of the correction constant adjustment procedures.
Adjustment Procedure Error Messages
ž POW MET INVALID
ž POW MET NOT SETTLED
• I POW MET NOT FOUND
The messages listed above indicate power meter problems.
Adjustments and Correction Constants
3-1
If the analyzer displays one of these messages, check:
n
n
n
n
the
the
the
the
test setup
line power
HP-IB connections and addresses
model number
After the problem has been identified and corrected, repeat the test.
n
TROUBLE! CHECK SET-UP AND START OVER
Check your setup against the illustrated test setup and repeat the test.
Perform Adjustments in This Order
When performing more than one adjustment, perform them in this order:
1. A9 CC Jumper Position Procedure
2. EEPROM Backup Disk Procedure
3. Initialize EEPROMs (Test #58)
4. Source Default Correction Constants (Test #44)
5. Source Pretune Default Correction Constants (Test #45)
6. Analog Bus Correction Constants (Test #46)
7. RF Output Power Correction Constants (Test #47)
8. Source Pretune Correction Constants (Test #48)
9. Display Intensity Adjustments (Test #49)
10. IF Amplifier Correction Constants (Test #51)
11. ADC Offset Correction Constants (Test #52)
12. Frequency Response Correction Constants (Tests #57 then #53)
13. Cavity Oscillator Correction Constants (Test #54)
14. Serial Number Correction Constant (Test #55)
15. Option Number Correction Constant (Test #56)
16. Model Number Correction Constant
17. Vertical Position and Focus Adjustments
18. Display Degaussing (Demagnetizing)
19. Fractional-N Frequency Range Adjustment
20. Frequency Accuracy Adjustment
21. High/Low Band Transition Adjustment
22. Fractional-N Spur and FM Sideband Adjustment
23. Source Spur Avoidance Tracking Adjustment
24. EEPROM Backup Disk Procedure
3-2
Adjustments and Correction Constants
Note
If you have replaced the CPU board, or if the analyzer has lost
all of its correction constants perform the adjustments in the
order listed below (from top to bottom):
1. A9 CC Jumper Position Procedure
12. Serial Number Correction Constant (Test #55)
13. Option Number Correction Constant (Test #56)
16. Model Number Correction Constant
14. Initialize EEPROMs (Test #58)
16. Model Number Correction Constant
7. Display Intensity Adjustments (Test #49)
17. Vertical Position and Focus Adjustments
18. Display Degaussing (Demagnetizing)
2. Source Default Correction Constants (Test #44)
3. Source Pretune Default Correction Constants (Test #45)
4. Analog Bus Correction Constants (Test #46)
9. ADC Offset Correction Constants (Test #52)
19. Fractional-N Frequency Range Adjustment
6. Source Pretune Correction Constants (Test #48)
20. Frequency Accuracy Adjustment
2 1. High/Low Band Transition Adjustment
22. Fractional-N Spur and FM Sideband Adjustment
23. Source Spur Avoidance Tracking Adjustment
5. RF Output Power Correction Constants (Test #47)
8. IF Amplifier Correction Constants (Test #51)
11. Cavity Oscillator Correction Constants (Test #54)
10. Frequency Response Correction Constants (Tests #57 then
#53)
15. EEPROM Backup Disk Procedure
Test Equipment Specifications
Each of the following procedures lists the equipment required to perform the
adjustment procedure. Typically, common hand tools (screwdrivers, etc.) are not
listed.
If you do not have the required equipment, refer to the critical specifications in
Table 1-1 to identify appropriate substitutes.
Adjustments and Correction Constants
3-3
Analyzer Cover Removal
Typically, when performing the analyzer’s adjustment procedures, only the top
cover needs to be removed (to adjust the A9CC jumper position).
To remove the top cover:
1. Remove the upper rear standoffs.
2. Loosen the top cover retaining screw.
3. Slide back the cover.
3-4
Adjustments and Correction Constants
1. A9 CC Jumper Position Procedure
A9 CC (Correction Constant) Jumper Position
To change the correction constants, you must move the A9 CC jumper to the
ALT (alter) position. The analyzer is shipped (and should be operated) with the
A9 CC jumper in the NRM (normal) position.
Procedure
Caution
Switch off the analyzer’s line power before removing or
installing assemblies.
Adjustments and Correction Constants
3-5
Al 6
(NOT VISIBLE)
A17
(NOT VISIBLE)
A3
A1
Figure 3-1. Location of Major Assemblies
3-6
Adjustments and Correction Constants
A6
1. Remove the analyzer top cover (see the section titled "Analyzer Cover
Removal," located earlier in this chapter).
2. Remove the PC board stabilizer (item 1, Figure 3-l).
3. Remove the A9 C P U assembly by pulling on the white lifters.
HP 8752 A9CPU Assembly
NRM
(Normal)
ALT
(Alter)
Figure 3-2. NRM (Normal) and ALT (Alter) Positions of A9 CC Jumper
4. Move the A9 CC jumper to the ALT position. Refer to Figure 3-2.
5. Reinstall the A9 assembly and run the correction constant routine(s).
6. Return the A9 CC jumper to the NRM position (see "1. A9 CC Jumper
Position Procedure").
Note
Update the EEPROM backup disk by performing "15. EEPROM
Backup Disk Procedure” at the end of this chapter.
Adjustments and Correction Constants
3-7
2. Source Default Correction Constants (Test #44)
Equipment
No equipment is required to perform this adjustment.
Warm-up time
5 minutes
Description and Procedure
This internal adjustment test writes default correction constants for
rudimentary source power accuracy. This adjustment must be performed before
the "Source Pretune Correction Constants (Test #45)" procedure.
1. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [44] [x1]. When the display shows
*Source Def -NDpress [EXECUTE TEST].
4. Press [YES] at the query to alter the correction constants.
5. When complete, DONE should appear on the display.
6. Refer to “15. EEPROM Backup Disk Procedure” to store the new correction
constants.
7. Return the A9 CC jumper to the NRM position (see "1. A9 CC Jumper
Position Procedure").
3-8
Adjustments and Correction Constants
3. Source Pretune Default Correction Constants
(Test #45)
Equipment
No equipment is required to perform this adjustment.
Warm-up time
30 minutes
Description and Procedure
This adjustment generates two default correction constants which pretune the
YIG oscillators to insure proper phase lock.
1. Put the A9 CC jumper in the ALT position (see “1. A9 CC Jumper Position
Procedure”).
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [45] [x1].
4. When the analyzer displays
*Pretune Def
press [EXECUTE TEST].
5. Press [YES] at the query to alter the correction constants and observe the
display:
n If *Pretune Def DONE is displayed, the adjustment is complete.
n Refer to “15. EEPROM Backup Disk Procedure” to store the new
correction constants. Return the A9 CC jumper to the NRM position (see
"1. A9 CC Jumper Position Procedure").
Adjustments and Correction Constants
3-9
4. Analog Bus Correction Constants (Test #46)
Equipment
No equipment is required for this adjustment.
Warm-up time
30 minutes
Description and Procedure
This procedure calibrates the analog bus using three reference voltages: ground,
+0.37V and +2.5V. It then stores the calibration data as correction constants in
EEPROM.
1. Put the A9 CC jumper in the ALT position (see “1. A9 CC Jumper Position
Procedure”).
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [46] [x1]. When the display shows:
ABUS Cor
press [EXECUTE TEST] and then press [YES] at the query to alter the correction
constants and observe the display:
ABUS COR DONE displayed: the adjustment is complete. Refer to “15.
EEPROM Backup Disk Procedure” to store the new correction constants.
Return the A9 CC jumper to the NRM position (see “1. A9 CC Jumper
Position Procedure”).
ABUS COR FAIL displayed: rerun the procedure; in case of continued
improper operation, refer to the chapter titled "Digital Control
Troubleshooting."
3-10
Adjustments and Correction Constants
5. RF Output Power Correction Constants (Test #47)
ANALYZER
POWER METER
Figure 3-3. Source Adjustment Setup
Equipment Required
*Use HP 8481A Option 006 above 4.2 GHz
Warm-up time
30 minutes
Description and Procedure
Several correction constants improve the output power level accuracy of the
internal source. They relate to power level, power slope, power slope offset,
and ALC roll-off factors.
1. Put the A9 CC jumper in the ALT position (see “1. A9 CC Jumper Position
Procedure”).
2. Press [PRESET]
Adjustments and Correction Constants
3-11
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [44] [x1] [EXECUTE TEST] [YES] to write
default correction constants for rudimentary source power accuracy.
4. Press [PRESET] [MEAS] [INPUT PORTS] [R] to measure input R.
5. Press [LOCAL] [SYSTEM CONTROLLER] [SET ADDRESSES]
[ADDRESS: P MTR/HPIB] to see the address at which the analyzer
expects to find the power meter (the default address is 13). Refer to the
power meter manual as required to observe or change its address to 13.
6. Press [POWER MTR: 438A/437] to toggle between 438A/437 and 436A to
match your power meter model number. When using the HP 438A, use
channel A.
Note
If you are using an HP 438A power meter, connect the
HP 8482A power sensor to channel A, and the HP 8481A power
sensor to channel B.
Power Sensor Calibration Factor Entry
7. Press [SYSTEM] [SERVICE MENU] [TEST OPTIONS] [LOSS/SENSR LISTS]
[CAL FACTOR SENSOR A] to access the calibration factor menu.
Note
-
n
In this menu, you can build a table of up to twelve points
(twelve frequencies with their cal factors). Cal factor and
frequency values are listed on the back of the power sensor.
Input the cal factor frequency as GHz or MHz by pressing the appropriate
entry key.
Input cal factor percentages as whole numbers (for example, enter CAL
FACTOR 98% as 98).
The following terms are part of the sensor calibration menu:
[SEGMENT]: press the softkey and use RPG or entry keys to select a point,
[EDIT] : press the softkey to change a previously entered value,
[DELETE]: press the softkey to delete a point from the table,
[ADD]: press the softkey to add a point to the table,
3-12
Adjustments and Correction Constants
[CLEAR LIST]: press the softkey to erase the entire table,
[DONE]: press the softkey when a table is complete and correct.
8. Press the appropriate so ftk eysto build a sensor calibration table.
Note
The Sensor’s reference calibration factor is the calibration factor
for 50 MHz.
9. Carefully zero and calibrate the power meter/sensor (refer to the power
meter/sensor manual as required).
Source Correction Routine
10. Press [SYSTEM] [SERVICE MENU] [TESTS] [47] [x1] to display Source Cor.
11. Press [EXECUTE TEST] and [YES] at the prompt to alter the correction
constants.
12. When prompted, connect the equipment as shown in Figure 3-3.
13. Follow the instructions on the screen and press [CONTINUE]. You can
reposition the marker as many times as required to achieve the flattest line.
If there is no appreciable rolloff, position the marker at the highest
frequency. Press [SELECT] to select the marker position which most
effectively flattens the trace.
DONE signals the successful conclusion of this routine. Refer to “15.
EEPROM Backup Disk Procedure” to store the new correction constants.
Return the A9 CC jumper to the NRM position (see “1. A9 CC Jumper
Position Procedure”).
FAIL is best handled by performing this procedure again.
In case of continued failure, refer to the chapter titled “Source
Troubleshooting."
Adjustments and Correction Constants
3-13
6. Source Pretune Correction Constants (Test #48)
Equipment Required
No equipment is required to perform this adjustment.
Warm-up time
30 minutes
Description and Procedure
This adjustment generates two correction constants which pretune the YIG
oscillators to insure proper phase lock.
1. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [48] [x1].
4. When the analyzer displays:
Pretune Cor
press [EXECUTE TEST]. Press [YES] at the query to alter the correction
constants and observe the display:
n Pretune Cor DONE displayed: the adjustment is complete and can be tested
by pressing [PRESET] and again observing the display:
q
Normal operation observed: the adjustment is complete. Refer to “15.
EEPROM Backup Disk Procedure” to store the new correction constants.
Return the A9 CC jumper to the NRM position (see “1. A9 CC Jumper
Position Procedure”).
q
Error messages observed: refer to the chapter titled "Source
Troubleshooting."
q
Continued improper operation: refer to the chapter titled "Source
Troubleshooting."
3-14
Adjustments and Correction Constants
7. Display Intensity Adjustments (Test #49)
Equipment Required
Warm-up time
30 minutes
Description and Procedure
There are three display intensity adjustments:
1. background
2. maximum
3. operating default
Perform these adjustments when either the A19 GSP, A9 CPU, or Al8 display
assemblies are replaced (as indicated in “Assembly Replacement and Post-Repair
Procedures”).
Note
This procedure should be performed with a photometer and only
by qualified service personnel.
Background Adjustment
1. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
2. In a dimly lit room (or with the analyzer’s display shaded from bright
lights), press [PRESET].
Adjustments and Correction Constants
3-15
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [49] [x1].
4. The analyzer should display:
Intensity Cor -ND-
Note
The display could be so far out of adjustment that the
annotation will be very difficult to read.
5. Press [EXECUTE TEST] (top softkey) and [YES] (second from top softkey) at
the prompt to alter the correction constants. Alternating vertical bars of
three different intensities will be drawn on the display. Each bar has a
number written below it (either 0, 1, or 2).
6. Adjust the analyzer’s RPG knob until the vertical bar labeled “1” is just
barely visible against the black border. Vertical bar “0” must not be visible.
Maximum Intensity Adjustment
This adjustment ensures that the light output at the 100% intensity level is
equal to, or less than, 150 NITs. The level is set using a photometer to measure
the display’s light output level.
Caution
3-16
Operating the display at intensities higher than 150 NITs may
reduce the life of the display.
Adjustments and Correction Constants
HP 8752C
NETWORK ANALYZER
PHOTOMETER
PHOTOMETER
PROBE
Figure 3-4. Maximum Intensity Adjustment Set-up
7. Press the top softkey.
8. Set the photometer probe to NORMAL. Press [POWER] on the photometer to
switch it on and allow 30 minutes warm-up. Zero the photometer according
to the manufacturer’s instructions. The analyzer display should have an all
white screen.
9. Center the photometer on the analyzer’s display as shown in Figure 3-4.
Adjust the analyzer’s RPG knob to the maximum (clockwise) position. If
the photometer registers greater than 150 NITs, turn the RPG knob until a
reading of no more than 150 NITs registers on the photometer without the
bezel (90 NITS with the bezel). If the photometer registers a reading of less
than 150 NITs and greater than 100 NITs, proceed to the next step. If the
photometer registers a reading of less than 100 NITs, the display is faulty.
Note
The above intensity levels are read without a display bezel
installed. The glass filter transmits 60% of the display light,
therefore 150 NITs would be 90 NITs with the bezel installed.
Adjustments and Correction Constants
3-17
Operating Default Intensity Adjustment
This adjustment sets the display’s default intensity level. The analyzer normally
presets to the same intensity level that was last used. This level is stored in
volatile memory. If the memory is lost, the analyzer will use the default display
intensity to ensure that the display is visible and to eliminate concern that the
display may not be functioning.
10. Press the top softkey on the analyzer to bring up the next display
adjustment mode.
11. Center the photometer on the analyzer’s display as shown in Figure 3-4.
Adjust the analyzer’s RPG knob until the photometer registers 100 NITs of
output light if the glass bezel assembly is not installed.
Adjust for 60 NITs if the glass bezel is installed.
12. Press the top softkey on the analyzer and observe the display:
n If DONE is displayed: the adjustment is complete. Refer to “15. EEPROM
Backup Disk Procedure” to store the new correction constants. This
completes the series of three display intensity adjustments. Return the
A9 CC jumper to the NRM position (see "1. A9 CC Jumper Position
Procedure").
n If the analyzer continues to operate improperly: refer to “Start
Troubleshooting Here” to isolate the problem.
3-18
Adjustments and Correction Constants
8. IF Amplifier Correction Constants (Test #51)
Equipment Required
RF cable
HP PN 8120-5639 HP PN 8120-5639
Pad attenuator
N/A
50/75 ohm min loss pad (2) N/A
HP 84918 Option 020
HP 11852B
Warm-up time
30 minutes
Description and Procedure
HP 8752C
HP 8752C OPTION 075
MINIMUM
LOSS PAD
50 ohm TYPE-N
RF THRU CABLE
50 ohm TYPE-N
RF THRU CABLE
sh654c
Figure 3-5. IF Amplifier Correction Constant Setup
These correction constants compensate for possible discontinuities of signals
greater than -30 dBm.
Adjustments and Correction Constants
3-19
1. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [51] [x1].
4. Press [EXECUTE TEST]
5. When
IF Step Cor
6.
7.
8.
9.
appears on the display, press [YES] at the query to alter the correction
constants.
At the prompt, remove any cable or device from the reflection port. Press
[CONTINUE].
At the prompt, connect the attenuator and RF cable as shown in Figure 3-5.
Press [CONTINUE].
If DONE is displayed: the adjustment is complete. Refer to “15. EEPROM
Backup Disk Procedure” to store the new correction constants. Return
the A9 CC jumper to the NRM position (see "1. A9 CC Jumper Position
Procedure").
If the procedure does not end with DONE, check the A9 CC jumper and the
setup and repeat. In case of difficulty, refer to the chapter titled “Digital
Control Troubleshooting.”
3-20
Adjustments and Correction Constants
9. ADC Offset Correction Constants (Test #52)
Equipment
No equipment is required to perform this adjustment.
Warm-up time
30 minutes
Description and Procedure
These correction constants improve dynamic accuracy by shifting small signals
to the most linear part of the ADC quantizing curve.
1. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [52] [x1]. When the analyzer displays:
ADC Ofs Cor
press [EXECUTE TEST].
4. Press [YES] at the query to alter the correction constants. Observe the
display:
n ADC Ofs Cor DONE displayed: the adjustment is complete. Refer to “15.
EEPROM Backup Disk Procedure” to store the new correction constants.
Return the A9 CC jumper to the NRM position (see "1. A9 CC Jumper
Position Procedure").
n ADC Ofs Cor FAIL displayed: rerun the routine; in case of continued
improper operation, refer to the chapter titled "Digital Control
Troubleshooting."
Adjustments and Correction Constants
3-21
10. Frequency Response Correction Constants
(Tests #53 and #57)
Equipment Required
Warm-up time
30 minutes
Description and Procedure
Perform "5. RF Output Power Correction Constants (Test #47)" before
continuing if you have replaced one or more of these assemblies:
-
n
n
n
A3 source
A9 CPU
A30 directional coupler
AT1 attenuator
Note
This procedure must be performed with the RF cable that will
be used with the analyzer. When the RF cable is replaced, this
procedure should be performed again to keep the correction
constants current.
1. Put the A9 CC jumper in the ALT position (see “1. A9 CC Jumper Position
Procedure”).
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [TESTS] [57] [x1] [EXECUTE TEST] [YES].
4. Press [SYSTEM] [SERVICE MENU] [TESTS] [53] [x1].
5. When Freq Resp Cor -ND- appears, press [EXECUTE TEST] [YES]. This allows
the correction constants to be altered.
6. Connect a standard, as prompted on the display, then press the
corresponding softkey.
3-22
Adjustments and Correction Constants
Note
For open and short standards, you must select an additional
softkey that indicates whether the test port is male or female.
In this case, it is female (f).
7. Press [DONE] after the standard is measured.
8. Measure all three standard types (short, open, load).
9. Press [DONE] [1-PORT CAL] to allow the analyzer to compute the calibration
coefficients. This takes about 20 seconds.
10. Connect the RF cable between the reflection and transmission test ports.
11. Press [THRU].
12. After the analyzer underlines THRU on the display, press [DONE: RESPONSE].
13. When the procedure is finished, look at the display:
n If DONE is displayed, this procedure is complete. Store the new correction
constants to disk. Refer to "15. EEPROM Backup Disk Procedure."
Return the A9 CC jumper to the NRM position (see "1. A9 CC Jumper
Position Procedure").
n If FAIL is displayed, refer to the chapter titled “Receiver
Troubleshooting.”
Adjustments and Correction Constants
3-23
11. Cavity Oscillator Frequency Correction Constants
(Test #54)
Equipment Required
Item
50 ohm Analyzers
Low-pass filter
HP PN 9136-0198 HP PN 9135-0198
RF cable
HP PN 8120-4781
HP PN 8120-4781
50 ohm to 75 ohm minimum loss pad (2) N/A
HP 11852B
APC-3.5(f) to type-N(m) adapter
1250-1744
1250-1744
APC-3.6(m) to type-N(f) adapter
1260-1760
1250-1750
Warm-up time
30 minutes
Description and Procedure
HP 8752C
OPTION 075
HP 8752C
LOSS PAD
LOSS PASS ADAPTER
FILTER
APC-3.5(m)
to N(f)
* DIRECT CONNECTION
ADAPTER
APC-3 5(f)
to N(m)
LOSS PASS
F I LTER
ADAPTER
APC-3.5(m)
to N(f)
sh655c
Figure 3-6. Cavity Oscillator Frequency Correction Constant Setup
3-24
Adjustments and Correction Constants
The nominal frequency of the cavity oscillator is 2.982 GHz, but it varies with
temperature. This procedure determines the precise frequency of the cavity
oscillator at a particular temperature by identifying a known spur.
Note
With the filter, the operator needs to distinguish between only
two spurs, each of which should be 10 dB to 20 dB (3 to 4
divisions) above the trace noise.
Without the filter, the target spur is one of four or five spurs,
each of which may be 0.002 to 0.010 dB (invisible to 2 divisions)
above or below the trace noise.
1. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
2. Connect the equipment as shown in Figure 3-6 and switch the analyzer’s
line power on.
3. Press [PRESET].
4. Press [SYSTEM] [SERVICE MENU] [TESTS] [54] [x1].
5. When the analyzer displays:
Cav Osc Cor
press [EXECUTE TEST]. Then press [YES] at the query to alter the correction
constants.
Note
During this adjustment routine, you will see several softkeys:
[CONTINUE] sweeps the current frequency span (may be
pressed repeatedly for additional looks at the current
frequency span).
[NEXT] sweeps the next frequency span (2 MHz higher).
[SELECT] enters the value of the marker (which should be on
the spur) and exits the routine.
[ABORT] exits the routine.
6. Press [CONTINUE] to sweep the first frequency span three times. If there are
no spurs displayed, press [NEXT].
Adjustments and Correction Constants
3-25
Note
Each new span overlaps the previous span by 3 MHz (the
center frequency increases by 2 MHz; the span is 5 MHz). Thus
anything visible on the right half of the display on one set of
sweeps will appear on the left half or center of the display.
Press [NEXT] repeatedly while watching the trace on each sweep and trying
to spot the target spur. With the filter, the target spur will be one of two
obvious spurs (see Figure 3-7). Without the filter (not recommended), it will
be one of four or five less distinct spurs as shown in Figure 3-9, Figure 3-10,
and Figure 3-11.
When the center frequency increases to 2994.999 MHz and you have not
targeted the selected spur, Cav Osc Cor FAIL appears on the display.
If you are confident that you found the target spur, continue with step 9
(filter procedure) or step 11 (filterless procedure). Otherwise repeat steps 5
through 8.
Spur Search Procedure with Filter
9. With the filter, the target spur will appear to the right of a second spur,
similar to Figure 3-7. Rotate the RPG knob to position the marker on the
spur.
3-26
Adjustments end Correction Constants
Figure 3-7. Typical Target Spur Using Filter
10. Press [SELECT] and observe the display:
n DONE appears: the procedure has been performed successfully. Refer
to “15. EEPROM Backup Disk Procedure” to store the new correction
constants.
If ND (not done) is displayed, repeat this procedure. Refer to “Source
Troubleshooting” if ND is still displayed.
-
Adjustments and Correction Constants
3-27
Spur Search Procedure without Filter
HP 8752C
INCH
‘F-N
CABLE
U
24 INCH
TYPE-N
RF CABLE
sh
Figure 3-8. Cavity Oscillator Frequency Correction Alternative Setup
11. Connect the test equipment as shown in Figure 3-8.
12. Without the filter, the target spur will appear in a variety of disguises.
Often it will be difficult to identify positively; occasionally it will be nearly
impossible to identify. Press [CONTINUE] as many times as necessary to
thoroughly inspect the current span. Without the filter, the target spur
usually appears as one of a group of four evenly spaced spurs, as in
Figure 3-9. The target spur is the right-most spur (fourth from the left). On
any particular sweep, any or all of the spurs may be large, small, visible,
invisible, above or below the reference line.
3-28
Adjustments and Correction Constants
sh6160c
Figure 3-9. Typical Display of Four Spurs without Filter
On occasion the target spur appears as one of a group of five evenly spaced
spurs, as in Figure 3-10. The target spur is again the fourth from the left
(not the fifth, right-most spur).
Adjustments and Correction Constants
3-29
Figure 3-10. Typical Display of Five Spurs without Filter
Figure 3-11 shows another variation of the basic four spur pattern: some
up, some down and the target spur itself almost indistinguishable.
3-30
Adjustments and Correction Constants
sh6162c
Figure 3-11. Variation of Display of Four Spurs without Filter
13. Rotate the RPG knob to position the marker on the target spur. Then press
[SELECT] and observe the display:
DONE appears: the procedure has been performed successfully. Refer
to "15. EEPROM Backup Disk Procedure" to store the new correction
constants. Return the A9 CC jumper to the NRM position (see "1. A9 CC
Jumper Position Procedure").
If ND (not done) is displayed, repeat this procedure. Refer to “Source
Troubleshooting” if ND is still displayed.
Adjustments and Correction Constants
3-31
12. Serial Number Correction Constant (Test #55)
Equipment
No equipment is required for this adjustment.
Warm-up time
6 minutes
Description and Procedure
This procedure customizes the replacement A9 CPU assembly by storing the
analyzer’s unique serial number as a correction constant in EEPROM.
Caution
Perform this procedure ONLY if the A9 CPU assembly has been
replaced.
1. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
2. Note the ten-character serial number on the analyzer’s rear panel
identification label.
3. Press [PRESET].
Caution
Mistakes cannot be corrected after step 5 is performed.
4. Press [DISPLAY] [MORE] [TITLE] [ERASE TITLE] to erase the HP logo. Rotate the
RPG knob to position the arrow below each character of the analyzer serial
number and press [SELECT LETTER] to enter each in turn. Enter a total of ten
characters: four digits, one letter, and five final digits.
Press [BACKSPACE] if you made a mistake. Press [DONE] when the title is
complete and correct.
5. Press [SYSTEM] [SERVICE MENU] [TESTS] [55] [x1] When the display shows:
Serial Cor
press [EXECUTE TEST]. Press [YES] at the query to alter the correction
constant.
3-32
Adjustments and Correction Constants
6. If this procedure did not end with DONE:
n The serial number entered did not conform to the required format, or
n a valid serial number was already stored.
-
In any case:
Confirm that the serial number is correct, and
n repeat this procedure.
Contact HP if the procedure still does not end with DONE.
7. To check the serial number recognized by the analyzer, press [PRESET]
[SYSTEM] [SERVICE MENU] [FIRMWARE REVISION]. The analyzer displays the
new serial number (SER. NO.). If not, repeat steps 3 through 6.
8. Refer to "15. EEPROM Backup Disk Procedure" to store the new correction
constants. Return the A9 CC jumper to the NRM position (see "1. A9 CC
Jumper Position Procedure").
Adjustments and Correction Constants
3-33
13. Option Numbers Correction Constant (Test #56)
Equipment
No equipment is required for this adjustment.
Warm-up time
5 minutes
Figure 3-12. Location of Keyword Label
3-34
Adjustments and Correction Constants
Description and Procedure
-
Special information is stored in the A9 CPU assembly if an analyzer has any of
(or any combination of) these options:
n
n
n
003 (3 GHz operation)
004 (attenuator)
006 (6 GHz operation)
010 (time domain)
This procedure restores that information after an A9 CPU assembly has been
replaced.
Perform this procedure only if:
n
n
n
the analyzer has one or more of the above options, and
the A9 CPU assembly has been replaced, and
the serial number correction constant procedure has been performed.
1. Put the A9 CC jumper in the ALT position (see “1. A9 CC Jumper Position
Procedure”).
2. Note the keyword label on the display (see Figure 3-12). The label has one
keyword for each option installed in the analyzer. If the analyzer lacks a
label, call your local HP Sales and Service office to obtain the keyword(s). Be
prepared to tell the service engineer the analyzer’s full serial number and the
options about to be installed on the analszer.
3. Press [PRESET].
4. Press [DISPLAY] [MORE] [TITLE] [ERASE TITLE]. Rotate the RPG knob to
position the arrow below each character of the first keyword, and press
[SELECT LETTER] to enter each in turn.
Press [BACKSPACE] if you made a mistake. When you have finished entering
the keyword, press [DONE].
Adjustments and Correction Constants
3-35
5. Press [SYSTEM] [SERVICE MENU] [TESTS] [56] [x1]. When the display shows:
Option Cor
-
press [EXECUTE TEST]. Press [YES] at the query to alter the correction
constant and observe the analyzer’s display:
n If DONE is displayed: the adjustment is complete. Continue with step 6.
FAIL is displayed: check the keyword again to make sure it is correct,
particularly if it contains the letters "I" or "O" or the numbers "1" or "0".
Repeat the procedure beginning with step 2. If the procedure continues to
fail, contact HP.
6. If the analyzer has more than one option, repeat steps 3, 4, and 5 to install
the remaining options. Refer to “15. EEPROM Backup Disk Procedure” to
store the new correction constants.
7. Return the A9 CC jumper to the NRM position (see "1. A9 CC Jumper
Position Procedure").
Option 004 Installation
1. Press [SYSTEM] [SERVICE MENU] [PEEK/POKE] [PEEK/POKE ADDRESS] [2621814] [x1]
[POKE]
[-1] [x1].
2. Press [PRESET] [SYSTEM] [SERVICE MENU] [FIRMWARE REVISION] .
3. Verify that Option 004 is shown on the analyzer’s display.
4. Refer to “15. EEPROM Backup Disk Procedure” to store the new correction
constants.
5. Return the A9 CC jumper to the NRM position (see “1. A9 CC Jumper
Position Procedure”).
3-36
Adjustments and Correction Constants
14. Initialize EEPROMs (Test #58)
-
This service internal test performs the following functions:
n
n
destroys all correction constants and all un-protected options
initializes certain EEPROM address locations to zeros
replaces the display intensity correction constants with default values
Note
This routine will not alter the serial number or Options 003, 006
and 010 correction constants.
1. Press [PRESET] [SYSTEM] [SERVICE MENU] [TESTS] [58] [x1] [EXECUTE TEST] [YES].
2. To restore the analyzer’s error correction constants:
-
n
If you have the correction constants backed up on a disk, refer to the
"EEPROM Backup Disk Procedure."
If you don’t have the correction constants backed up on a disk, run all the
internal service routines in the following order:
Source Default Correction Constants (Test #44)
Source Pretune Correction Constants (Test #45)
Analog Bus Correction Constants (Test #46)
RF Output Power Correction Constants (Test #47)
Source Pretune Correction Constants (Test #48)
Display Intensity (Test #49)
IF Amplifier Correction Constants (Test #51)
ADC Offset Correction Constants (Test #52)
Frequency Response Correction Constants (Test #57 then #53)
Calibration Kit Default Correction Constants (Test #57)
Cavity Oscillator Frequency Correction Constants (Test #54)
Adjustments and Correction Constants
3-37
15. EEPROM Backup Disk Procedure
Equipment Required
Item
HP Model
CS80 disk drive
HP 9122
HP-IB cable
HP 10833A/B/C/D
3.5-inch disk
blank disk or supplied EEPROM Calibration Data Disk
Warm-up time
None
Description and Procedure
HP-IB
Figure 3-13. EEPROM Backup Procedure Setup
A unique EEPROM Calibration Data Disk is shipped from the factory with
each analyzer. This disk is a record of the calibration constants (CCs) stored in
EEPROM on the A9 CPU assembly. It allows you to replace the A9 CPU board
assembly without having to rerun all of the correction constant adjustment
procedures.
n
n
Take care of the supplied EEPROM Calibration Data Disk:
• If you don’t have the original, make a backup disk and keep it current.
Store the correction constant data to the EEPROM Calibration Data Disk each
time you perform one or more correction constant routines.
3-38
Adjustments and Correction Constants
n
Retrieve correction constant data from the EEPROM Calibration Data Disk if
you need to replace the A9 CPU board assembly.
How to Make an EEPROM Backup Disk and Store CCs and Data
to It
1. Set the disk drive to HP-IB address 00. Insert a disk in drive 0.
2. Connect the instruments as shown in Figure 3-13. Switch on the analyzer
first, followed by the disk drive.
3. Press [LOCAL] [SYSTEM CONTROLLER].
4. Press [SAVE/RECALL] [SELECT DISK] [CONFIGURE EXT DISK]. Set the disk
address, disk unit number, and volume number to 0.
5. Press [RETURN] [EXTERNAL DISK]:
n
If the NA does not toggle from [INTERNAL MEMORY] to [EXTERNAL DISK]:
Make sure the drive is powered up, its address correct, and that the
HP-IB cable is OK.
Make sure the supplied disk or an initialized, non-write protected disk is
in place:
n If the disk is not initialized, press [SAVE/RECALL] [FILE UTILITIES]
[FORMAT DISK] [FORMAT EXT DISK] [YES].
6. Press [SYSTEM] [SERVICE MENU] [SERVICE MODES] [MORE] [STORE EEPR ON]
[SAVE/RECALL] [SAVE STATE] to store the EEPROM data with the instrument
state. This step stores the correction constants in a default file named
“ISTATE0” on the floppy disk.
7. Press [SAVE/RECALL] [FILE UTILITIES] and use the RPG to highlight the file
"ISTATE0."
8. Press [RENAME FILE] [ERASE TITLE].
Then use the RPG and softkeys to title the file N12345 (the first character
must be a letter; 12345 represent the last five digits of the analyzer’s serial
number).
9. When finished, press [DONE].
10. Label the disk with this information:
n the serial number of the analyzer
n the words “EEPROM Backup Disk”
n today’s date
Adjustments and Correction Constants
3-39
How to Recall CC Data from the EEPROM Disk into the
Analyzer
1. Set the disk drive to HP-IB address 00 and insert the EEPROM Disk.
2. Connect the instruments as shown in Figure 3-13.
3. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
4. Install the new A9 assembly.
5. Switch on the disk drive and then the analyzer:
n If the display is dark:
• Press [DISPLAY] [MORE] (bottom softkey)
q
[ADJUST DISPLAY] (fourth softkey from top)
[INTENSITY] (top softkey) and then turn the RPG knob.
If the display is unfocused: see “17. Vertical Position and Focus
Adjustments” for more information.
q
n
Note
Disregard noisy trace data or error messages that appear on the
display at this time.
6. Press [LOCAL] [SYSTEM CONTROLLER].
7. Press [SAVE/RECALL] [SELECT DISK] [CONFIGURE EXT DISK]. Set the disk
address, disk unit number, and volume number to 0.
8. Press [SAVE/RECALL] [SELECT DISK] [EXTERNAL DISK].
Note
If the analyzer does not toggle to [EXTERNAL DISK] , switch off
the instruments, turn on the disk drive and then the analyzer,
check its HP-IB address and cable.
9. Press [SAVE/RECALL] and use the RPG to highlight the file (FILE1 on the
original EEPROM Calibration Data Disk or file N12345 where N12345
represents the filename of the EEPROM Backup Disk).
10. Press [RETURN] [RECALL STATE].
11. Perform the serial number (service internal test #55) and the option number
correction constant routines (service internal test #56), if applicable.
12. Press [PRESET] and verify that good data was transferred to EEPROM by
performing a simple measurement.
3-40
Adjustments and Correction Constants
13. Return the A9 CC jumper to the NRM position (see "1. A9 CC Jumper
Position Procedure").
n In case of difficulty, refer to the chapter titled "Start Troubleshooting
Here."
Adjustments and Correction Constants
3-41
16. Model Number Correction Constant
(Option 075 Only)
Equipment
No equipment is required for this adjustment.
Warmup time
5 minutes
Description and Procedure
This procedure sets an EEPROM bit for HP 8752C analyzers with Option 075 so
that certain system default values will be correct after the A9 CPU assembly
firmware is replaced.
Firmware and A9 CPU assemblies are shipped with the bit set correctly for
HP 8752C analyzers without Option 075.
Caution
After installing new A9 CPU or new firmware, but before
performing this procedure, perform “15. EEPROM Backup Disk
Procedure” found at the end of this chapter.
1. Put the A9 CC jumper in the ALT position (see "1. A9 CC Jumper Position
Procedure").
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [PEEK/POKE] [PEEK/POKE] [ADDRESS] [2621808] [x1]
[POKE] [1] [x1] [RESET MEMORY] [PRESET].
4. To verify that the procedure was successful, press [SYSTEM] [SERVICE MENU]
[FIRMWARE REVISION]. Opt 075 should appear on the display. If Opt 075
is not displayed, repeat the procedure. Contact the nearest HP sales and
service office if the procedure was not successful.
5. Return the A9 CC jumper to the NRM position (see "1. A9 CC Jumper
Position Procedure").
3-42
Adjustments and Correction Constants
17. Vertical Position and Focus Adjustments
Equipment
Narrow, non-conductive, flathead screwdriver, 2-inches long
Warmup time
30 minutes
Description and Procedure
Only vertical position and focus, can be adjusted in the field (this includes both
customers and service centers). These adjustments are optional and should
rarely be required.
Caution
Any other adjustments to the display will void the warranty.
Vertical Position Adjustment
1. To access vertical and focus adjustments controls, remove the side panel
nearest to the display.
Adjustments and Correction Constants
3-43
FOCUS
A
CON
ADJUSTMEN
Figure 3-14. Vertical Position and Focus Adjustment Controls
2. Insert a narrow, non-conductive, flat head screw driver (at least 2-inches
long) into the vertical position hole. See Figure 3-14.
3. Adjust the control until the softkey labels are aligned with the softkeys.
Focus Adjustment
4. Use the same screwdriver to adjust the focus until the display is the most
readable.
3-44
Adjustments and Correction Constants
18. Display Degaussing (Demagnetizing)
Equipment
Any CRT demagnetizer or bulk tape eraser
Warm-up time
5 minutes
Description and Procedure
All color
symptom
corner of
observed;
monitors are susceptible to external magnetic fields. The usual
is a discoloration or slight dimming, usually occurring near the top left
the analyzer’s display. In extreme cases, a total color shift may be
for example, a trace that was red may shift to green.
Like most displays, the CRT can be sensitive to large magnetic fields generated
from unshielded motors. In countries that use a 50 Hz line voltage frequency,
some 10 Hz jitter may be observed. If this problem is observed, remove the
device causing the magnetic field.
Should the display become magnetized or if color purity is a problem, cycle
the power several times. Leave the analyzer off for at least 30 seconds before
switching it on. This will activate the automatic degaussing circuitry in the
display. If this is insufficient to achieve color purity, use a commercially
available demagnetizer (either a CRT demagnetizer or a bulk tape eraser).
Follow the manufacturer’s instructions keeping in mind the following:
n
n
Initially use the demagnetizer no closer than 4 inches (10 cm) from the face of
the CRT.
If needed, try again at a slightly closer distance until the CRT is
demagnetized.
Caution
Applying a strong magnetic field to the CRT face can
permanently destroy it.
Adjustments and Correction Constants
3-45
19. Fractional-N Frequency Range Adjustment
Equipment Required
No equipment is required to perform this adjustment procedure.
Warm-up time
30 minutes
Description and Procedure
This adjustment centers the fractional-N VCO (voltage controlled oscillator) in its
tuning range to insure reliable operation of the analyzer.
1. Remove the analyzer right side panel.
2. Press [PRESET].
3. Press [DISPLAY] [DUAL CHAN ON] [MENU] [NUMBER of POINTS] [11] [x1]
[COUPLED CH OFF].
4. Press [START] [36] [M/u] [STOP] [60.75] [M/u] [MENU] [SWEEP TIME] [12.5] [k/m]
[SYSTEM] [SERVICE MENU] [ANALOG BUS ON] [MEAS] [ANALOG
[x1] to observe the “FN VCO Tune” voltage.
IN Aux Input] [29]
Press [SCALE REF] [.6] [x1] [REFERENCE VALUE] [-7] [x1] to set and scale
channel 1.
5. Press [MKR] to set the marker to the far right of the graticule.
6. Press [CH 2] [MENU] [CW FREQ] [31.0001] [M/u] [SWEEP TIME] [12.375] [k/m] [MEAS]
[ANALOG IN Aux Input] [29] [x1] to observe the “FN VCO Tune” voltage. Press
[SCALE REF] [.2] [x1] [REFERENCE VALUE] [6.77] [x1] [MKR] [6] [k/m] to set channel 2
and its marker.
3-46
Adjustments and Correction Constants
FN VCO ADJ
Yellow
•
TP12
A14 Fractional-N Adjustment Location
TP14
q
Figure 3-15. FN VCO TUNE Adjustment Location
7. Observe the analyzer display for the results of the adjustment.
a. Refer to Figure 3-15. If the marker value is less than 7, the adjustment
procedure is complete.
Adjustments and Correction Constants
3-47
AUX
CH1 START
CH2 AUX
Re
600 mU/
Re
36.000 000 MHZ
200 mU/
CH2 START 0 s
CW
REF
-7 U
STOP
REF 6.77 U
31.000 100 MHZ
13 Mar 1995 15: 16: 42
1_ -6.3496 U
60.750 000 MHZ
1_: 6.5772 U
STOP .012 s
sh6157c
Figure 3-16. Fractional-N Frequency Range Adjustment Display
b. If the marker value is greater than 7, readjust FN VCO ADJ to 7 (refer to
Figure 3-14). Perform steps 2 through 7 to confirm that the channel 1 and
channel 2 markers respectively are still above and below the reference
line.
c. If the adjustment cannot be performed correctly, replace the Al4 board
assembly.
3-48
Adjustments and Correction Constants
20. Frequency Accuracy Adjustment
Equipment Required
Item
500 to 750 minimum loss pad*
type-N cable
type-N(f) to BNC(m) adapter
Frequency counter
HP Model Number
HP 11852B
HP PN 8120-4781
HP PN 1250-0077
HP 6343A
*Option 075 analyzers only.
Warm-up time
30 minutes
HP8752C OPT 075
HP5343A
TYPE - N
CABLE
HP5343A
TYPE-N CABLE
Figure 3-17.
Reflection Test PortOutput Frequency Accuracy Adjustment Setup
Note
For 750 analyzers, insert an HP 11852B 500 to 750 minimum loss
pad and adapters between frequency counter port and type-N
cable.
Adjustments and Correction Constants
3-49
Description and Procedure
This adjustment sets the VCXO (voltage controlled crystal oscillator) frequency
to maintain the analyzer’s frequency accuracy.
1. Remove the analyzer’s top cover and connect the equipment as shown in
Figure 3-17.
2. Press [PRESET].
3. Press [MENU] [CW FREQ] [50] [M/u] and note the frequency:
Frequency = 50 MHz ±500 Hz: no adjustment is required.
n To adjust the frequency, locate the Al2 assembly (red extractors) and
adjust VCXO ADJ (see Figure 3-18) for a frequency counter reading of
50 MHz ±500 Hz.
4. If you are unable to adjust the frequency as specified, replace the A12
assembly.
-
RED
VCO ADJ
(C85)
VCXO
ADJ
A12 Reference Assembly
sg64d
Figure 3-18. VCXO ADJ Adjustment Location
3-50
Adjustments and Correction Constants
21. High/Low Band Transition Adjustment
Equipment Required
No equipment is required for this adjustment procedure.
Warm-up time
30 minutes
Description and Procedure
This adjustment centers the VCO (voltage controlled oscillator) of the A12
reference assembly for reliable high band and low band operation.
1. Remove the top cover (see "1. A9CC Jumper Position Procedure"). Remove
the PC board stabilizer and place the Al2 assembly on an extender board.
Use extension SMB cables as needed.
2. Press [PRESET].
3. Press [SYSTEM] [SERVICE MENU] [ANALOG BUS ON] [START] [11] [M/u] [STOP] [21]
[M/u] to observe part of both the low and high bands on the analog bus.
4. Press [MEAS] [ANALOG IN Aux Input] [22] [x1] [DISPLAY] [DATA->MEM] [DATA-MEM]
to subtract the ground voltage from the next measurement.
5. Press [MEAS] [ANALOG IN A12 Gnd 1] [23] [x1] [MKR] [11] [M/u].
6. Press [MKR FCTN] [MARKER->REFERENCE] [SCALE REF] [.1] [x1] and observe the
VCO tune voltage trace:
n Left half of trace = 0 ±1000 mV and right half of trace = 100 to 200 mV
higher (one to two divisions, see Figure 3-19): no adjustment necessary.
Adjustments and Correction Constants
3-51
Figure 3-19. High/Low Band Transition Adjustment Trace
n
To adjust: turn VCO TUNE (see Figure 3-20) to position the left half of the
trace to 0±125 mV. Then adjust HBLB to position the right half of the trace
125 to 175 mV (about 1 1/2 divisions) higher than the left half.
HBLB
ADJ
VCO
TUNE
(C85)
A12 R e f e r e n c e A s s e m b l y
Figure 3-20. High/Low Band Adjustments Locations
3-52
Adjustments and Correction Constants
7. In some cases, the VCO TUNE adjustment may need to be performed first.
If you are having trouble with the high low band adjustment, perform the
following procedure:
a. Press:
[SYSTEM]
[SERVICE MENU] [ANALOG BUS ON]
[START] [10] [M/µ] [STOP] [10] [M/µ]
b. Press:
[MEAS] [ANALOG
IN Aux INPUT] [22] [x1]
[DISPLAY] [DATA->MEMORY]
[DATA-MEM]
c. Press:
[MEAS] [ANALOG
IN Aux INPUT] [23] [x1]
[FORMAT] [MORE] [REAL]
d. Adjust C85 (VCO TUNE) to 0 units ± 100 mU.
e. Press [SYSTEM] [SERVICE MENU] [ANALOG BUS ON] [START] [11] [M/u] [STOP]
[21] [M/u] to observe part of both the low and high bands on the analog
bus.
f. Press [MEAS] [ANALOG IN Aux Input] [22] [x1] [DISPLAY] [DATA->MEM]
[DATA-MEM] to subtract the ground voltage from the next measurement.
g. Press [MEAS] [ANALOG IN A12 Gnd 1] [23] [x1] [MKR] [11] [M/u].
h. Press [MKR FCTN] [MARKER->REFERENCE] [SCALE REF] [.1] [x1] and observe the
VCO tune voltage trace:
n Left half of trace = 0 ±1000 mV and right half of trace = 100 to 200 mV
higher (one to two divisions, see Figure 3-19): no adjustment necessary.
If you still cannot perform the high/low band adjustment, refer to the
chapter titled “Source Troubleshooting.”
Adjustments and Correction Constants
3-53
22. Fractional-N Spur Avoidance and FM Sideband
Adjustment
Equipment Required
Item
HP Model Number
Spectrum Analyzer
HP 8563E
RF Cable 600, type-N, 24-inch
HP PIN 8120-4781
Cable, 500 Coax, BNC (m) to BNC (m)
HP 10603A
Non-metallic Adjustment Tool
HP P/N 8830-0024
Antistatic Wrist Strap
HP P/N 93001367
Antistatic Wrist Strap Cord
HP P/N 8300-0980
Static-control Table Mat and Earth Ground Wire HP P/N 9300-0797
50 ohm to 75 ohm Minimum Loss Pad*
HP 11862B
*Option 075 analyzers only.
Warmup time
30 minutes
Description and Procedure
This adjustment minimizes the spurs caused by the API (analog phase
interpolator, on the fractional-N assembly) circuits. It also improves the
sideband characteristics.
1. Connect the equipment as shown in Figure 3-21.
2. Make sure the instruments are set to their default HP-IB addresses:
HP 8752C = 16, Spectrum Analyzer = 18.
3-54
Adjustments end Correction Constants
EXT REF INPUT
YZER
Figure 3-21.
Fractional-N Spur Avoidance and FM Sideband Adjustment Setup
3. Set the spectrum analyzer measurement parameters as follows:
Reference Level .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..0 dBm
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Hz
Resolution Bandwidth
Center Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676.145105 MHz
Adjustments and Correction Constants
3-55
4. On the HP 87526, press [PRESET] [CENTER] [676.045105] [M/µ].
5. Refer to Figure 3-22. Adjust the 100 kHz (R77) for a null (minimum
amplitude) on the spectrum analyzer. The minimum signal may, or may not,
drop down into the noise floor.
ORANGE
100kHz
(R77)
A13
API1 API2
(R35) ( R 4 3
Fractional-N
API3
(R45)
Analog
API4
(R47)
Assembly
Figure 3-22. Location of API and 100 kHz Adjustments
6. On the spectrum analyzer, set the center frequency for 676.048105 MHz.
7. On the HP 8752C, press [CENTER]) [676.048105] [M/µ].
8. Adjust the API1 (R35) for a null (minimum amplitude) on the spectrum
analyzer.
9. On the spectrum analyzer, set the center frequency for 676.007515 MHz.
10. On the HP 87526, press [CENTER] [676.004515] [M/µ].
11. Adjust the API2 (R43) for a null (minimum amplitude) on the spectrum
analyzer.
12. On the spectrum analyzer, set the center frequency for 676.003450 MHz.
13. On the HP 8752C, press [CENTER] [676.00045] [M/µ].
14. Adjust the API3 (R45) for a null (minimum amplitude) on the spectrum
analyzer.
15. On the spectrum analyzer, set the center frequency for 676.003045 MHz.
3-56
Adjustments and Correction Constants
16. On the HP 8752C, press [CENTER] [676.000045] [M/µ].
17. Adjust the API4 (R47) for a null (minimum amplitude) on the spectrum
analyzer.
In Case of Difficulty
18. If this adjustment cannot be performed satisfactorily, repeat the entire
procedure. If the adjustment is still unattainable, replace the A13 board
assembly.
Adjustments and Correction Constants
3-57
23. Source Spur Avoidance Tracking Adjustment
Equipment Required
Warm-up time
30 minutes
Description and Procedure
This adjustment optimizes tracking between the YO (YIG oscillator) and the
cavity oscillator when they are frequency offset to avoid spurs. Optimizing
YO-cavity oscillator tracking minimizes fluctuations in the phase-locked loop.
1. Mate a BNC-alligator clip to the BNC cable and connect the BNC end to AUX
INPUT on the rear panel. Connect the alligator-clip to AllTPlO (labeled Ø
ERR). Connect the shield clip to A11TP1 (GND), shown in Figure 3-23.
A11TP1
GNO
BROWN
A11
Phase
Lock
A11TP10
Ø ERR
Assembly
UNLK
C A V ADJ
A3
Source
Figure 3-23. All Test Point and A3 CAV ADJ Locations
3-58
Adjustments and Correction Constants
2. Press [PRESET].
3. Press [CENTER] [400] [M/u] [SPAN] [50] [M/u] to generate a sweep from 375 MHz
to 425 MHz.
4. Press [SYSTEM] [SERVICE MENU] [ANALOG BUS ON] [MEAS]
--
[ANALOG IN Aux Input] [11] [x1] [SCALE REF] [10] [k/m] [MKR FCTN]
[MARKER->REFERENCE] to observe the phase-locked loop error voltage:
If spikes are not visible on the display (see Figure 3-24): no adjustment is
necessary.
If spikes are excessive (see Figure 3-24): adjust the CAV ADJ potentiometer
(see Figure 3-23) on the A3 source bias assembly to eliminate the spikes.
5. Refer to “Start Troubleshooting Here” if visible spikes persist.
CENTER
a) Acceptable
400.000
000
MHz
SPAN 50.000
000 MHz
b) Excessive
sg637s
Figure 3-24. Display of Acceptable Versus Excessive Spikes
Adjustments and Correction Constants
3-59
Start Troubleshooting Here
The information in this chapter helps you:
n
Identify the portion of the analyzer that is at fault.
n
Locate the specific troubleshooting procedures to identify the assembly or
peripheral at fault.
To identify the portion of the analyzer at fault, follow these procedures:
Step 1. Initial Observations
Step 2. Confidence Test
Step 3. HP-IB System Check
Step 4. Faulty Group Isolation
Start Troubleshooting Here
4-1
Assembly Replacement Sequence
The following steps show the sequence to replace an assembly in an HP 8752C
Network Analyzer.
1. Identify the faulty group. Refer to the “Start Troubleshooting Here” chapter.
Follow up with the appropriate troubleshooting chapter that identifies the
faulty assembly.
2. Order a replacement assembly. Refer to the “Replaceable Parts” chapter.
3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to the “Assembly Replacement and Post-Repair Procedures” chapter.
4. Perform the necessary adjustments. Refer to the “Adjustments and
Correction Constants” chapter.
5. Perform the necessary performance tests. Refer to the “System Verification
and Performance Tests” chapter.
Having Your Analyzer Serviced
The HP 8752C has a one year on-site warranty, where available. If the analyzer
should fail any of the following checks, call your local HP sales and service
office. A customer engineer will be dispatched to service your analyzer on-site.
If a customer engineer is not available in your area, follow the steps below to
send your analyzer back to HP for repair.
1. Choose the nearest HP service center. (Hewlett-Packard sales and service
offices are listed in the “Safety and Licensing” chapter.)
2. Include a detailed description of any failed test and any error message.
3. Ship the analyzer, using the original or comparable antistatic packaging
materials.
4-2
Start Troubleshooting Here
Step 1. Initial Observations
Initiate the Analyzer Self-Test
1. Disconnect all devices and peripherals from the analyzer.
2. Switch on the analyzer and press [PRESET].
3. Watch for the indications in the order shown in Figure 4-1 to determine if the
analyzer is operating correctly.
Figure 4-1. LED Power-up Sequence
If the Self-Test Failed
1. Check the AC line power to the analyzer.
2. Check the fuse (rating listed on rear panel, spare inside holder).
3. Check the line voltage setting (use small screwdriver to change).
4. If the problem persists, refer to “Step 4. Faulty Group Isolation”.
Start Troubleshooting Here
4-3
Step 2. Confidence Test
The confidence test verifies that the circuits in the analyzer are functioning
properly. However, it does not verify the accessories or the analyzer
specifications.
The resulting measurement must fall within a limit testing window to pass the
test. The window size is based on both source and receiver specifications. The
characteristics tested are combinations of: source match, reflection tracking,
directivity, transmission tracking, noise floor, and crosstalk.
The confidence test adds all the applicable error terms together. To separate
them out or to keep a record of them for maintenance, refer to the “Error
Terms” chapter.
If you want to test the individual analyzer specifications then refer to the
“Verification and Performance Tests” chapter.
Procedure
1. Select the test data printing status.
If you do not want the test data to automatically print, continue with
step 2.
n
n
If you want to have the test data automatically print, press [PRESET]
[SYSTEM] [SERVICE MENU] [TEST OPTIONS] [RECORD ON].
Note
When using an InkJet printer, the analyzer must be set to the
standard print mode through the [copy] menu.
2. Press [SYSTEM] [SERVICE MENU] [TESTS] [EXTERNAL TESTS] [EXECUTE TEST].
The analyzer should display a short description of the test and a reminder of
the RECORD function.
3. Press [CONTINUE] to begin the test.
4. Disconnect all devices from the reflection test port, as prompted on the
analyzer display.
5. Press [CONTINUE] to run the “source match, tracking” test. There should be
a PASS/FAIL result displayed on the analyzer.
4-4
Start Troubleshooting Here
6. Press [CONTINUE] to run the “transmission crosstalk, noise floor” test. (With
the record function on, this test will automatically run). There should be a
PASS/FAIL result displayed on the analyzer.
7. Press [CONTINUE] and then connect the RF cable supplied with the analyzer
between the reflection and transmission test ports.
8. Press [CONTINUE] to run the “transmission tracking, source/load match” test.
There should be a PASS/FAIL result displayed on the analyzer.
9. Press [CONTINUE] to run the “load match, directivity” test. (With the record
function on, this test will automatically run.) There should be a PASS/FAIL
result displayed on the analyzer.
10. Press [CONTINUE] again.
The analyzer now displays the result of the confidence test. If the test
failed:
q
It could be due to loose connections. Tighten all connections and repeat
the Confidence Test.
q
It could be due to a bad frequency response correction. Run service
test 53.
q
It could be due to a faulty RF cable. Run the cable confidence test
(service test 22) or replace the cable. Run the verification procedure
(test 27) to identify which error term is causing the failure.
Cable Confidence Test
This test provides an easy check of the RF performance of the transmission
cable supplied with the HP 8752C.
The test limits used are the sum of the HP 8752C specifications that apply, plus
the uncertainties in the measurement.
Procedure
1. Press [PRESET] [SYSTEM] [SERVICE MENU] [TESTS] [EXTERNAL TESTS] [22] [x1].
The analyzer should display:
TEST
22 CABLE CONFID -ND-
Start Troubleshooting Here
4-5
2. Press [EXECUTE TEST]. The analyzer now displays a brief description of the
test and the test limits.
3. Press [CONTINUE] to begin the test. Connect an RF cable between the
reflection and the transmission test ports, as prompted on the analyzer.
4. Press [CONTINUE] and notice the PASS/FAIL result.
q
q
If the cable passes the test: press [CONTINUE] again and move the cable
gently in all possible directions to see if it stays within the limits.
If the cable fails the test: replace the cable.
Refer to “Step 4. Faulty Group Isolation” in this chapter if the problem persists
and the analyzer does not use HP-IB.
4-6
Start Troubleshooting Here
Step 3. HP-IB Systems Check
Check the analyzer’s HP-IB functions with a known working passive peripheral
(such as a plotter, printer, or disk drive).
1. Connect the peripheral to the analyzer using a good HP-IB cable..
2. Press [LOCAL] [SYSTEM CONTROLLER] to enable the analyzer to control the
peripheral.
3. Then press [SET ADDRESSES] and the appropriate softkeys to verify that the
device addresses will be recognized by the analyzer. The factory default
addresses are:
Device
HP-IB Address
HP 8752C
16
Plotter port - HP-IB
5
Printer port - HP-IB
1
Disk (external)
0
Controller
21
Power meter - HP-IB
13
Note
You may use other addresses with two provisions:
n
Each device must have its own address.
n
The address set on each device must match the one
recognized by the analyzer (and displayed).
Peripheral addresses are often set with a rear panel switch.
Refer to the manual of the peripheral to read or change its
address.
Start Troubleshooting Here
4-7
If Using a Plotter or Printer
1. Ensure that the plotter or printer is set up correctly:
n
power is on
n
pens and paper loaded
n
pinch wheels are down
n
some plotters need to have P1 and P2 positions set
2. Press [COPY] and then [PLOT] or [PRINT MONOCHROME].
q
If the result is a copy of the analyzer display, the printing/plotting features
are functional in the analyzer. Continue with "Troubleshooting Systems
with Multiple Peripherals," “Troubleshooting Systems with Controllers,” or
the “Step 4. Faulty Group Isolation” section in this chapter.
q
If the result is not a copy of the analyzer display, suspect the HP-IB
function of the analyzer: refer to the “Digital Control Troubleshooting”
chapter.
If Using an External Disk Drive
1. Select the external disk drive. Press [SAVE/RECALL] [SELECT DISK]
[EXTERNAL DISK].
2. Verify that the address is set correctly. Press [LOCAL] [SET ADDRESSES]
[ADDRESS: DISK].
3. Ensure that the disk drive is set up correctly:
4-8
n
power is on
n
an initialized disk in the correct drive
n
correct disk unit number and volume number (press [LOCAL] to access the
softkeys that display the numbers; default is 0 for both)
n
with hard disk (Winchester) drives, make sure the configuration switch is
properly set (see drive manual)
Start Troubleshooting Here
4. Press [START] [1] [M/µ] [SAVE/RECALL] [SAVE STATE]. Then press [PRESET]
[SAVE/RECALL] [RECALL STATE].
q
If the resultant trace starts at 1 MHz, HP-IB is functional in the analyzer.
Continue with "Troubleshooting Systems with Multiple Peripherals,"
“Troubleshooting Systems with Controllers,” or the “Step 4. Faulty Group
Isolation” section in this chapter.
q
If the resultant trace does not start at 1 MHz, suspect the HP-IB function
of the analyzer: refer to the “Digital Control Troubleshooting” chapter.
Troubleshooting Systems with Multiple Peripherals
Connect any other system peripherals (but not a controller) to the analyzer
one at a time and check their functionality. Any problems observed are in the
peripherals, cables, or are address problems (see above).
Troubleshooting Systems with Controllers
Passing the preceding checks indicates that the analyzer’s peripheral functions
are normal. Therefore, if the analyzer has not been operating properly with an
external controller, suspect the controller. Check the following:
n
-
n
n
n
Compatibility of controller, must be HP 9000 series 200/300. (Refer to the
“Service Equipment and Analyzer Options” chapter.)
HP-IB interface hardware is installed. (Refer to the manual, Installing and
Maintaining HP Basic/WS 6.2, that comes with your HP Basic software.)
Select code is correct. (Refer to the manual, Installing and Maintaining
HP Basic/WS 6.2, that comes with your HP Basic software.)
I/O and HP-IB binaries are loaded. (Refer to the manual, Installing and
Maintaining HP Basic/WS 6.2, that comes with your HP Basic software.)
HP-IB cables. (See “HP-1B Requirements” in the HP 8752C Network Analyzer
User’s Guide.)
Programming syntax is correct. (Refer to the HP 8752C Network Analyzer
Programmer’s Guide.)
If the analyzer appears to be operating unexpectedly but has not completely
failed, go to “Step 4. Faulty Group Isolation.”
Start Troubleshooting Here
4-9
Step 4. Faulty Group Isolation
Use the following procedures only if you have read the previous sections in
this chapter and you think the problem is in the analyzer. These are simple
procedures to verify the four functional groups in sequence, and determine
which group is faulty.
-
The four functional groups are:
n
power supplies
digital control
n
source
n
receiver
Descriptions of these groups are provided in the “Theory of Operation” chapter.
The checks in the following pages must be performed in the order presented.
If one of the procedures fails, it is an indication that the problem is in the
functional group checked. Go to the troubleshooting information for the
indicated group, to isolate the problem to the defective assembly.
Figure 4-2 illustrates the troubleshooting organization.
ISOLATE FAULTY GROUP
ASSEMBLY L E V E L T R O U B L E S H O O T I N G
sg645d
Figure 4-2. Troubleshooting Organization
4-10
Start Troubleshooting Here
Power Supply Check
Check the Rear Panel LEDs
Switch on the analyzer. Notice the condition of the two LEDs on the Al5
preregulator at rear of the analyzer (see Figure 4-3).
q
The upper (red) LED should be off.
q
The lower (green) LED should be on.
Red LED
Normally
Off
Green LED
Normally On
Line Voltage
Selector
Switch
sh663c
Figure 4-3. Al5 Preregulator LEDs
Check the A8 Post Regulator LEDs
Remove the analyzer’s top cover. Inspect the green LEDs along the top edge of
the A8 post regulator assembly.
q
All green LEDs should be on.
q
The fan should be audible.
In case of difficulty, refer to the “Power Supply Troubleshooting” chapter.
Start Troubleshooting Here
4-11
Digital Control Check
Observe the Power Up Sequence
-
Switch the analyzer power off, then on. The following should take place within
a few seconds:
On the front panel observe the following:
1. All six amber LEDs illuminate.
2. The amber LEDs go off after a few seconds, except the CH 1 LED. (See
Figure 4-4).
n
The display should come up bright and focused.
Figure 4-4. Front Panel Power-up Sequence
4-12
Start Troubleshooting Here
Verify Internal Tests Passed
1. Press [PRESET] [SYSTEM] [SERVICE MENU] [TESTS] [INTERNAL TESTS]
[EXECUTE TEST]. The display should indicate:
TEST
0
q
ALL INT
PASS
If your display shows the above message, go to step 2. Otherwise, continue
with this step.
q
If phase lock error messages are present, this test may stop without passing
or failing. In this case, continue with the next procedure to check the
source.
q
If you have unexpected results, or if the analyzer indicates a specific test
failure, that internal test (and possibly others) have failed; the analyzer
reports the first failure detected. Refer to the “Service Key Menus and
Error Messages” chapter for internal test information; then refer to the
“Digital Control Troubleshooting” chapter.
q
If the analyzer indicates failure but does not identify the test, press
to search for the failed test. (For a description of the failed test refer to
the “Service Key Menus” chapter.) Then refer to the “Digital Control
Troubleshooting” chapter. Likewise, if the response to front panel or HP-IB
commands is unexpected, troubleshoot the digital control group.
2. To perform the Analog Bus test, press [RETURN] [19] [x1] [EXECUTE TEST].
q
If this test fails, refer to the “Digital Control Troubleshooting” chapter.
q
If this test passes, continue with the next procedure to check the source.
Source Check
-
1. Check the display for any of the following phase lock error messages:
NO IF FOUND: CHECKR INPUT LEVEL
n
NO PHASE LOCK: CHECK R INPUT LEVEL
n
PHASE LOCK LOST
n
PHASE LOCK CAL FAILED
If any of these error messages appear, refer to the “Source Troubleshooting”
chapter. Otherwise, continue with the next step.
Start Troubleshooting Here
4-13
2. Connect the equipment as shown in Figure 4-5.
* special option power sensor
NETWORK
ANALYZER
POWER SENSOR
Figure 4-5. Equipment Setup for Source Power Check
3. Switch on the instruments. Zero and calibrate the power meter.
4. On the analyzer, press [PRESET] Stimulus [MENU] [POWER] [-20] [x1] [MENU]
[CW FREQ] [300] [K/m]. The power meter should read approximately -20 dBm
(-85 dBm for Option 004).
5. Press [16] [M/µ] to change the CW frequency to 16 MHz. The power meter
should read approximately -20 dBm throughout the analyzer’s frequency
range. Repeat checking the frequency at 1 GHz intervals up to the maximum
frequency of the analyzer.
6. Press [POWER] [5] [x1] to increase the output power to 5 dBm (+ 10 dBm for
Option 004).
7. Step through the frequencies as above: the power meter should read
approximately 5 dBm at all frequencies (+ 10 dBm with Option 004).
If any incorrect power levels are measured, refer to the “Source
Troubleshooting” chapter. Otherwise, continue with "Receiver Check."
4-14
Start Troubleshooting Here
Receiver Check
1. Connect an RF cable directly between the reflection and transmission ports.
2. On the analyzer, press [PRESET] [MEAS] [TRANSMISSION] [SCALE REF] [.5] [x1].
3. Notice the condition of the trace: it should resemble Figure 4-6
If the trace shows unexpected results, refer to the “Receiver Troubleshooting”
chapter.
Figure 4-6. Typical Measurement Trace
Accessories Check
If the analyzer has passed all of the above checks but is still making incorrect
measurements, an accessory could be faulty: RF cables, interconnect cables, and
calibration kit devices can all induce system problems.
Reconfigure the system to its normal state and reconfirm the problem. If the
problem persists, refer to the “Accessories Troubleshooting” chapter.
Start Troubleshooting Here
4-15
Power Supply Troubleshooting
Use this procedure only if you have read the “Start Troubleshooting Here”
chapter. Follow the procedures in the order given, unless:
q
q
an error message appears on the display, refer to “Error Messages” near the
end of this chapter.
the fan is not working, refer to “Fan Troubleshooting” in this chapter.
The power supply group assemblies consist of the following:
n
A8 post regulator
n
Al5 preregulator
All assemblies, however, are related to the power supply group because power is
supplied to each assembly.
Power Supply Troubleshooting
5-1
Assembly Replacement Sequence
The following steps show the sequence to replace an assembly in an HP 8752C
Network Analyzer.
1. Identify the faulty group. Refer to the “Start Troubleshooting Here” chapter.
Follow up with the appropriate troubleshooting chapter that identifies the
faulty assembly.
2. Order a replacement assembly. Refer to the “Replaceable Parts” chapter.
3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to the “Assembly Replacement and Post-Repair Procedures” chapter.
4. Perform the necessary adjustments. Refer to the “Adjustments and
Correction Constants” chapter.
5. Perform the necessary performance tests. Refer to the “System Verification
and Performance Tests” chapter.
5-2
Power Supply Troubleshooting
Simplified Block Diagram
Figure 5-l shows the power supply group in simplified block diagram form.
Refer to the detailed block diagram of the power supply (Figure 5-8) located at
the end of this chapter to see voltage lines and specific connector pin numbers.
OFF DURING
NORMAL OPERATION
ALL ON DURING
N O R M A L OPERATION
\- ON DURING
NORMAL OPERATION
sg636d
Figure 5-1. Power Supply Group Simplified Block Diagram
Power Supply Troubleshooting
5-3
Start Here
Check the Green LED and Red LED on A15
Switch on the analyzer and look at the rear panel of the analyzer. Check the
two power supply diagnostic LEDs on the Al5 preregulator casting by looking
through the holes located to the left of the line voltage selector switch (see
Figure 5-2).
During normal operation, the bottom (green) LED is on and the top (red) LED is
off. If these LEDs are normal, then Al5 is 95% verified. Continue with "Check
the Green LEDs on A8".
• If
the green LED is not on steadily, refer to “If the Green LED on Al5 is not
On Steadily” in this procedure.
• If
the red LED is on or flashing, refer to “If the Red LED On Al5 is On” in
this procedure.
Red LED
Normally
Off
Green LED
Normally On
Line
Voltage
Selector Switch
sh663c
Figure 5-2. Location of Al5 Diagnostic LEDs
5-4
Power Supply Troubleshooting
Check the Green LEDs on A8
1. Remove the top cover of the analyzer and locate the A8 post regulator. Use
the location diagram under the top cover if necessary.
2. Check to see if the green LEDs on the top edge of A8 are all on. There
are nine green LEDs (one is not visible without removing the PC board
stabilizer).
q
q
If all of the green LEDs on the top edge of A8 are on, there is a 95%
confidence level that the power supply is verified. To confirm the last 5%
uncertainty of the power supply, refer to “Measure the Post Regulator
Voltages” (next).
If any LED on the A8 post regulator is off or flashing, refer to “If the
Green LEDs On A8 are not All On” in this chapter.
Measure the Post Regulator Voltages
Measure the DC voltages on the test points of A8 with a voltmeter. Refer to
Figure 5-3 for test point locations and Table 5-l for supply voltages and limits.
+65V
\\
AGND
\•
2
W14
PLUG
+5VD
SDIS
-15v
\ \
\
O• •
3
-12.6VPP +15V +5VU
/
•O•O
4
/
O•
7
/
O•
-5.2V
+22V
+6V
O
8
11
A15W1
PLUG
sh664c
Figure 5-3. A8 Post Regulator Test Point Locations
Power Supply Troubleshooting
5-5
Table 5-1. A8 Post Regulator Test Point Voltages
TP
1
2
+ 65V
AGND
Range
+ 64.6 to + 65.4
n/a
3
+5 VD
+ 4.9 to + 5.3
4
SDIS
n/a
5
-15V
6
7
-12.6 VPP (probe power)
+ 15V
- 14.4 to -16.6
- 12.1 to -12.8
+ 14.6 to + 15.5
8
+5 VU
+5.05 to +5.35
4
-5.2 V
-5.0 to -6.4
10
11
5-6
Supply
+ 22V
+6V
Power Supply Troubleshooting
+21.3 to +22.7
+ 6.8 too+ 6.2
If the Green LED on Al5 is not On Steadily
If the green LED is not on steadily, the line voltage is missing or is not enough
to power the analyzer.
Check the Line Voltage, Selector Switch, and Fuse
1. Check the main power line cord, line fuse, line selector switch setting, and
actual line voltage to see that they are all correct. Figure 5-4 shows how to
remove the line fuse, using a small flat-bladed screwdriver to pry out the fuse
holder. Figure 5-2 shows the location of the line voltage selector switch.
2. Use a small flat-bladed screwdriver to select the correct switch position.
q
If the Al5 green LED is still not on steadily, replace A15.
FUSE IN USE
INSERT SCREWDRIVER,
PRY OPEN
Figure 5-4. Removing the Line Fuse
Power Supply Troubleshooting
5-7
If the Red LED On A15 is On
If the red LED is on or flashing, the power supply is shutting down. Use the
following procedures to determine which assembly is causing the problem.
Check the A8 Post Regulator
1. Switch off the analyzer.
2. Disconnect the cable A15W1 from the A8 post regulator (see Figure 5-5).
3. Switch on the analyzer and observe the red LED on A15.
If the red LED goes out, the problem is probably the A8 post regulator.
Continue with “Verify the Al5 Preregulator” to first verify that the inputs
to A8 are correct.
If the red LED is still on, the problem is probably the Al5 preregulator, or
one of the assemblies obtaining power from it. Continue with "Check for a
Faulty Assembly."
5-8
Power Supply Troubleshooting
A15W1 ( T O P O S T
REGULATOR A8J2)
Al5
PREREGULATOR
A15W1 (TO
MOTHERBOARD
A17J2)
W20
W14 ( D I S P L A Y
POWER CABLE)
Al9 GRAPHICS
PROCESSOR
A8 POST
REGULATOR
A18 DISPLAY
(INSIDE)
FRONT
sh6200d
Figure 5-5. Power Supply Cable Locations
Verify the Al5 Preregulator
Verify that the Al5 preregulator is supplying the correct voltages to the A8 post
regulator. Use a voltmeter with a small probe to measure the output voltages of
A15W1's plug. Refer to Table 5-2 and Figure 5-6.
q
q
If the voltages are not within tolerance, replace A15.
If the voltages are within tolerance, Al5 is verified. Continue with "Check for
a Faulty Assembly."
Power Supply Troubleshooting
5-9
Table 5-2. Output Voltages
Pin
A15W1P1 (Disconnected)
Voltages
A8J2 (Connected) Voltages
Al5 Preregulator Mnemonic
1,2
+ 125 to + 100
+688to +72
+ 70V
3,4
+ 22.4 to +33.6
+ 17.0 to + 18.4
+ 18V
5,6
-22.4 to -33.6
- 17.0 to -18.4
- 18V
N/C
7
N/C
N/C
8
+9.4 to +14
+7.44to 18.0
+8 V
9,10
-9.4 to -14
-6.7 to -7.3
-8 V
11
+32 to +48
+24.6 to +26.6
+25V
12
N/C
N/C
N/C
NOTE: The + 5VD supply must be loaded by one or more assemblies at all times, or the other voltages will not
be correct. It connects to motherboard connector A17J3 Pin 4.
5-10
Power Supply Troubleshooting
1
FROM A15 PREREGULATOR
PLUG IN BACK
A8 POST
REGULATOR
SOLDER SIDE
A15J2 V O L T A G E S - A L L C A B L E S A N D
ASSEMBLIES CONNECTED
sh667c
Figure 5-6. A15W1 Plug Detail
Check for a Faulty Assembly
This procedure checks for a faulty assembly that might be shutting down the
Al5 preregulator via one of the following lines (also refer to Figure 5-l):
-
n
the A15W1 cable connected to the A8 post regulator
n
the + 5VCPU line through the motherboard
the +5VDIG line through the motherboard
Power Supply Troubleshooting
5-11
Do the following:
1. Switch off the analyzer.
2. Ensure that A15W1 is reconnected to AS (refer to Figure 5-5).
3. Remove or disconnect the assemblies listed in Table 5-3 one at a time and in
the order shown. The assemblies are sorted from most to least accessible.
Table 5-3 also lists any associated assemblies that receive power from
the assembly that is being removed. After each assembly is removed or
disconnected, switch on the analyzer and observe the red LED on A15.
--
Note
Always switch off the analyzer before removing or
disconnecting assemblies.
When extensive disassembly is required, refer the “Assembly
Replacement and Post-Repair Procedures” chapter.
Refer to the “Replaceable Parts” chapter to identify specific
cables and assemblies that are not shown in this chapter.
q
If the red LED goes out, the particular assembly removed (or one receiving
power from it) is faulty.
q
If the red LED is still on after you have checked all of the assemblies listed in
Table 5-3, continue with “Check the Operating Temperature.”
Table 5-3. Recommended Order for Removal/Disconnection
Assembly
To Remove
1. A19 Graphics Processor
2. A14 Frac N Digital
3. A9 CPU
Removal or
Disconnection Method
Disconnect W14
5-12
A18
Display
Remove from Card Cage None
Remove from Card Cage
4. A16 Rear Panel Interface Disconnect A16W1
6. A2 Front Panel Interface
Other Assemblies that Receive
Power from the Removed Assembly
Disconnect W17
Power Supply Troubleshooting
None
None
A1 Front Panel
Keyboard
Check the Operating Temperature
The temperature sensing circuitry inside the A15 preregulator may be shutting
down the supply. Make sure the temperature of the open air operating
environment does not exceed 55 °C (131 °F) and that the analyzer fan is
operating.
q
If the fan does not seem to be operating correctly, refer to “Fan
Troubleshooting” at the end of this procedure.
q
If there does not appear to be a temperature problem, it is likely that A15 is
faulty.
Inspect the Motherboard
If the red LED is still on after replacement or repair of A15, switch off the
analyzer and inspect the motherboard for solder bridges, and other noticeable
defects. Use an ohmmeter to check for shorts. The + 5VD, + 5VCPU, or
+ 5VDSENSE lines may be bad. Refer to the block diagram (Figure 5-8) at the
end of this chapter and troubleshoot these suspected power supply lines on the
A17 motherboard.
Power Supply Troubleshooting
5-13
If the Green LEDs On A8 are not All On
The green LEDs along the top edge of the A8 post regulator are normally on.
Flashing LED s on A8 indicate that the shutdown circuitry on the A8 post
regulator is protecting power supplies from overcurrent conditions by
repeatedly shutting them down. This may be caused by supply loading on A8 or
on any other assembly in the analyzer.
Remove A8, Maintain A15W1 Cable Connection
1. Switch off the analyzer.
2. Remove A8 from its motherboard connector, but keep the A15W1 cable
connected to A8.
3. Remove the display power cable W14 (see Figure 5-5).
4. Short A8TP2 (AGND) (see Figure 5-3) to chassis ground with a clip lead.
5. Switch on the analyzer and observe the green LEDs on A8.
q
If any green LEDs other than +5VD are still off or flashing, continue with
“Check the A8 Fuses and Voltages.”
q
If all LEDs are now on steadily except for the +5VD LED, the Al5
preregulator and A8 post regulator are working properly and the trouble
is excessive loading somewhere after the motherboard connections at A8.
Continue with “Remove the Assemblies.”
Check the A8 Fuses and Voltages
Check the fuses along the top edge of A8. If any A8 fuse has burned out,
replace it. If it burns out again when power is applied to the analyzer, A8 or
A15 is faulty. Determine which assembly has failed as follows.
1. Remove the A15W1 cable at A8 (see Figure 5-5).
2. Measure the voltages at A15W1P1 (see Figure 5-6) with a voltmeter that has
a small probe.
3. Compare the measured voltages with those in Table 5-2.
q
If the voltages are within tolerance, replace A8.
q
If the voltages are not within tolerance, replace A15.
5-14
Power Supply Troubleshooting
If the green LEDs are now on, the Al5 preregulator and A8 post regulator are
working properly and the trouble is excessive loading somewhere after the
motherboard connections at A8. Continue with “Remove the Assemblies.”
Remove the Assemblies
1. Switch off the analyzer.
2. Install A8. Remove the jumper from A8TP2 (AGND) to chassis ground.
3. Remove or disconnect all the assemblies listed below (see Figure 5-5).
Always switch off the analyzer before removing or disconnecting an
assembly.
A9 CPU
A10 digital IF
Al 1 phase lock
Al2 reference
Al3 fractional-N analog
Al4 fractional-N digital
A19 graphics processor (disconnect W14, A18W1, and W20)
4. Switch on the analyzer and observe the green LEDs on A8.
If any of the green LEDs are off or flashing, it is not likely that any of the
assemblies listed above is causing the problem. Continue with, "Briefly
Disable the Shutdown Circuitry."
If all green LEDs are now on, one or more of the above assemblies may
be faulty. Continue with next step.
q
q
5. Switch off the analyzer.
6. Reconnect W14 and W20 to A19.
7. Switch on the analyzer and observe the LEDs.
q
q
If the LEDs are off or blinking, replace the A19 assembly.
If the LEDs are still on, continue with next step.
8. Switch off the analyzer.
9. Reconnect A18W1 to the A19 assembly.
10. Switch on the analyzer and observe the LEDs.
q
q
If the LEDs are off, replace the Al8 display.
If the LEDs are still on, continue with the next step.
Power Supply Troubleshooting
5-15
11. Switch off the analyzer.
12. Reinstall each assembly one at a time. Switch on the analyzer after each
assembly is installed. The assembly that causes the green LEDs to go off or
flash could be faulty.
Note
It is possible, however, that this condition is caused by the
A8 post regulator not supplying enough current. To check
this, reinstall the assemblies in a different order to change the
loading. If the same assembly appears to be faulty, replace that
assembly. If a different assembly appears faulty, A8 is most
likely faulty (unless both of the other assemblies are faulty).
Briefly Disable the Shutdown Circuitry
In this step, you shutdown the protective circuitry for a short time, and the
supplies are forced on (including shorted supplies) with a 100% duty cycle.
Caution
Damage to components or to circuit traces may occur if A8TP4
(SDIS) is shorted to chassis ground for more than a few seconds.
1. Switch off the analyzer.
2. Connect A8TP4 (SDIS) to chassis ground with a jumper wire.
3. Switch on the analyzer and notice the LEDs that are off. Immediately
remove the jumper wire.
4. Refer to the block diagram (Figure 5-8) at the end of this chapter and do the
following:
a. Notice any additional signals that may connect to any A8 test point that
showed a fault in the previous step.
b. Cross reference all assemblies that use the power supplies whose A8 LEDs
went out when A8TP4 (SDIS) was connected to chassis ground.
5-16
Power Supply Troubleshooting
c. Make a list of these assemblies.
d. Delete the following assemblies from your list as they have already been
verified earlier in this section.
A9 CPU
Al0 digital IF
All phase lock
Al2 reference
Al3 fractional-N analog
Al4 fractional-N digital
A18 display
A19 graphics processor
5. Switch off the analyzer.
6. Of those assemblies that are left on the list, remove or disconnect them
from the analyzer one at a time. Table 5-4 shows the best order in which
to remove them. Table 5-4 also lists any associated assemblies that recieve
power by the assembly that is being removed. After each assembly is
removed or disconnected switch on the analyzer and observe the LEDs.
Note
-
Always switch off the analyzer before removing or
disconnecting assemblies.
n
When extensive disassembly is required, refer to the
“Assembly Replacement and Post-Repair Procedures” chapter.
n
Refer to the “Replaceable Parts” chapter to identify specific
cables and assemblies that are not shown in this chapter.
q
If all the LEDs light, the assembly removed (or one receiving power from it) is
faulty.
q
If the LEDs are still not on steadily, continue with “Inspect the Motherboard.”
Power Supply Troubleshooting
5-17
Table 5-4. Recommended Order for Removal/Disconnection
Assembly
To Remove
1. A3 Source
2. A7 Pulse Generator
Removal or
Disconnection Method
Other Assemblies that Receive
Power from the Removed Assembly
Remove from Card Cage None
Remove from Card Cage
None
3. A4 R Sampler
Remove from Card Cage
4. A5 A Sampler
Remove from Card Cage None
53. A6 B Sampler
Remove from Card Cage None
6. A2 Front Panel Interface Disconnect W17
7. Al6 Rear Panel Interface Disconnect A16W1
None
A1 Front Panel
Keyboard
|None
Inspect the Motherboard
Inspect the A17 motherboard for solder bridges and shorted traces. In
particular, inspect the traces that carry the supplies whose LEDs faulted when
A8TP4 (SDIS) was grounded earlier.
5-18
Power Supply Troubleshooting
Error Messages
Three error messages are associated with the power supplies functional group.
They are shown here.
POWERSUPPLY SHUT DOWN!
One or more supplies on the A8 post regulator assembly is shut down due to
one of the following conditions: overcurrent, overvoltage, or undervoltage.
Refer to “If the Red LED On Al5 is On” earlier in this procedure.
POWER SUPPLY HOT!
The temperature sensors on the A8 post regulator assembly detect, an
overtemperature condition. The regulated power supplies on A8 have been
shut down.
Check the temperature of the operating environment; it should not be greater
than + 55 °C (131 °F). The fan should be operating and there should be at
least 15 cm (6 in) spacing behind and all around the analyzer to allow for
proper ventilation.
PROBE POWER SHUT DOWN!
The front panel RF probe biasing supplies are shut down due to excessively
drawb current. These supplies are + 15VPP and -12.6VPP, both supplied by
the A8 post regulator. + 15VPP is derived from the + 15V supply. -12.6VPP is
derived from the -12.6V supply.
Refer to Figure 5-7 and carefully measure the power supply voltages at the
front panel RF probe connectors.
Power Supply Troubleshooting
5-19
sh668c
Figure 5-7. Front Panel Probe Power Connector Voltages
q
q
If the correct voltages are present, troubleshoot the probe.
If the voltages are not present, check the + 15V and -12.6V green LEDs on
A8.
n
n
5-20
If the LEDs are on, there is an open between the A8 assembly and the
front panel probe power connectors. Put A8 onto an extender board and
measure the voltages at the following pins:
A8P2 pins 6 and 36
- 12.6 volts
A8P2 pins 4 and 34
+ 15 volts
If the LEDs are off, continue with "Check the Fuses and Isolate A8."
Power Supply Troubleshooting
Check the Fuses and Isolate A8
1. Check the fuses associated with each of these supplies near the A8 test
points. If these fuses keep burning out, a short exists.
2. Try isolating A8 by removing it from the motherboard connector, but keeping
the cable A15W1 connected to A8J2.
3. Connect a jumper wire from A8TP2 to chassis ground.
q
If either the + 15V or -12.6V fuse blows, or the associated green LEDs do
not light, replace A8.
q
If the + 15V and -12.6V green LEDs light, troubleshoot for a short
between the motherboard connector pins XA8P2 pins 6 and 36 (-12.6V)
and the front panel probe power connectors. Also check between
motherboard connector pins XA8P2 pins 4 and 34 (+ 15V) and the front
panel probe power connectors.
Power Supply Troubleshooting
5-21
Fan Troubleshooting
Fan Speeds
The fan speed varies depending upon temperature. It is normal for the fan to
be at high speed when the analyzer is just switched on, and then change to low
speed when the analyzer is cooled.
Check the Fan Voltages
1. If the fan is dead, refer to the A8 post regulator block diagram (Figure 5-8)
at the end of this chapter. The fan is driven by the + 18V and -18V supplies
coming from the Al5 preregulator. Neither of these supplies is fused.
The -18V supply is regulated on A8 in the fan drive block, and remains
constant at approximately -14 volts. It connects to the Al7 motherboard via
pin 32 of the A8P1 connector.
The +18V supply is regulated on A8 but changes the voltage to the fan,
depending on airflow and temperature information. Its voltage ranges
from approximately -1.0 volts to +14.7 volts, and connects to the A17
motherboard via pin 31 of the A8P1 connector.
2. Measure the voltages of these supplies while using an extender board to
allow access to the PC board connector, A8P1.
Short A8TP3 to Ground
1. If there is no voltage at A8P1 pins 31 and 32, switch off the analyzer.
Remove A8 from its motherboard connector (or extender board) but keep the
cable A15W1 connected to A8 (see Figure 5-5).
2. Connect a jumper wire between A8TP3 and chassis ground.
3. Switch on the analyzer and observe the green LEDs.
q
If all the green LEDs on the top edge of A8 light (except +5VD), replace
the fan.
q
If other green LEDs on A8 do not light, refer to “If the Green LEDs On A8
are not All On” earlier in this procedure.
5-22
Power Supply Troubleshooting
Intermittent Problems
PRESET states that appear spontaneously (without pressing [PRESET]) typically
signal a power supply or A9 CPU problem. Since the A9 CPU assembly is
the easiest to substitute, do so. If the problem ceases, replace the A9. If the
problem continues, replace the A15 preregulator assembly.
Power Supply Troubleshooting
5-23
6
Digital Control Troubleshooting
Use this procedure only if you have read the “Start Troubleshooting Here”
chapter. Follow the procedures in the order given, unless instructed otherwise.
If you suspect an HP-IB interface problem, refer to "HP-IB Failures" at the end
of this chapter.
The digital control group assemblies consist of the following:
n
Al front panel keyboard
n
A2 front panel interface
n
--
A9 CPU
n
A10 digital IF
n
Al6 rear panel
A18 display
A19 GSP
Digital Control Troubleshooting
6-1
Assembly Replacement Sequence
The following steps show the sequence to replace an assembly in an HP 8752C
Network Analyzer.
1. Identify the faulty group. Refer to the “Start Troubleshooting Here” chapter.
Follow up with the appropriate troubleshooting chapter that identifies the
faulty assembly.
2. Order a replacement assembly. Refer to the “Replaceable Parts” chapter.
3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to the “Assembly Replacement and Post-Repair Procedures” chapter.
4. Perform the necessary adjustments. Refer to the “Adjustments and
Correction Constants” chapter.
5. Perform the necessary performance tests. Refer to the “System Verification
and Performance Tests” chapter.
6-2
Digital Control Troubleshooting
Digital Control Group Block Diagram
sh6101c
Figure 6-l. Digital Control Group Block Diagram
Digital Control Troubleshooting
6-3
Check A9 CPU Operation
A9 CC Jumper Positions
The A9 CC jumper must be in the “NRM” (normal) position for these procedures.
This is the position for normal operating conditions. To move the jumper to the
"NRM" position, do the following:
1. Unplug the analyzer.
2. Remove the top cover.
3. Remove the A9 CPU board.
4. Move the jumper to the NRM position. (Refer to Figure 6-2.)
5. Replace the A9 CPU board, top cover, and power cord.
H P 8 7 5 2 A9CPU A s s e m b l y
NRM
(Normal)
ALT
(Alter)
Figure 6-2. Jumper Positions on the A9 CPU
6-4
Digital Control Troubleshooting
Checking A9 CPU Red LED Patterns
The A9 CPU has four red LEDs that can be viewed by removing the top cover.
[Refer to “Major Assemblies” in Chapter 13 to locate the A9 CPU and Figure 6-3
to identify the LEDs.)
1. Cycle the power
Cycle the power on the analyzer and observe the four red LEDs. All four
LEDs should be on after power up.
If the four LEDs did not illuminate, replace the A9 CPU after verifying the
power supply.
2. Hold in the preset key
Press and hold down the [PRESET] key while observing the four LEDs on A9.
The far left LED should be off. (See Figure 6-3.)
4 RED
LEDS
HP
8 7 5 2 A9CPU
Assembly
Figure 6-3. Location of Four LEDs on A9 CPU
Digital Control Troubleshooting
6-5
3. Release the preset key
Release the [PRESET] key and watch for the rapid sequence shown below.
Notice that the far left LED always remains on. (The filled circles represent
illuminated LEDs.)
o
•
•
•
[PRESET] still held down
•
•
•
•
[PRESET]
•
o
•
•
Pattern 2
•
•
•
•
Pattern 3
•
o
•
o
Pattern 4
•
•
•
•
Pattern 5 - two left LEDs flicker
•
•
•
o
Pattern 6
•
•
•
•
Pattern 7 - two left LEDs flicker
released - Pattern 1
4. Observe and evaluate results
q
If the above sequence is observed, and the far right LED remained on, go
to “Check A19 GSP and Al8 Display Operation.”
q
If the right LED does not remain on, replace the A9 CPU assembly and
repeat the three LED pattern checks.
q
If the LEDs are held in any one of the patterns shown in Table 6-1, and
have the corresponding error message, replace the A9 firmware ICs.
(Firmware ICs are not separately replaceable. Replacement kits are listed
in the “Replaceable Parts” chapter.)
Table 6-1. LED Code and Pattern Versus Test Failed
LED Code Sum
RUN
1
2
4
o
•
•
•
•
•
•
•
•
•
ROM 1L FAIL
o
ROM 2L FAIL
•
•
•
6-6
Message Displayed
Faulty Component
U24
U25
•
ROM 1M FAIL
U4
o
ROM 2M FAIL
U5
Digital Control Troubleshooting
Check A19 GSP and Al8 Display Operation
Cycle Power and Look at the Display
Switch the analyzer off, and then on. The display should be bright and focused
with the annotation legible and intelligible.
q
If the display is acceptable, go to "A1/A2 Front Panel Troubleshooting."
q
If the display is unacceptable, continue with the next step.
Perform Display Intensity and Focus Adjustments
Refer to the “Adjustments and Correction Constants” chapter, and perform the
“Display Intensity Adjustments.” If this does not resolve the problem, refer to
“A19 GSP and Al8 Display Troubleshooting,” located later in this chapter.
A1/A2 Front Panel Troubleshooting
Check Front Panel LEDs After Preset
1. Press [PRESET] on the analyzer.
2. Observe that all front panel LEDs turn on and, within five seconds after
releasing [PRESET], all but the CH1 LED turns off. Refer to Figure 6-4.
q
If all the front panel LEDs either stay on or off, there is a control problem
between A9 and A1/A2. See “Inspect Cables,” located later in this chapter.
q
If, at the end of the turn on sequence, the channel 1 LED is not on and all
HP-IB status LEDs are not off, continue with "Identify the Stuck Key."
Digital Control Troubleshooting
6-7
Figure 6-4. Preset Sequence
Identify the Stuck Key
Match the LED pattern with the patterns in Table 6-2. The LED pattern
identifies the stuck key. Free the stuck key or replace the front panel part
causing the problem.
6-8
Digital Control Troubleshooting
Table 6-2. Front Panel Key Codes
Decimal
Number
LED Pattern
CH1
CH2
R
Key
L
T
Front Panel Block
S
0
Response
1
•
•
2
3
•
•
•
•
4
5
6
7
•
•
•
•
•
•
•
•
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
26
•
•
•
•
•
•
•
•
•
•
•
Entry
•
Response
Entry
Response
•
•
•
•
•
•
•
•
•
•
•
Entry
Entry
[softkey
3]
[softkey 5]
Softkey
[9]
[G/n]
Entry
•
Active Channel
•
•
•
•
•
Entry
Entry
•
[softkey 1]
•
[SAVE/RECALL]
•
•
•
•
Entry
Active Channel
[STOP]
•
•
•
Softkey
Softkey
Stimulus
Instrument state
[SEQ]
Instrument State
[MENU]
Stimulus
Stimulus
•
•
•
Instrument State
Instrument State
•
Softkey
Response
•
Entry
Digital Control Troubleshooting
6-9
Table 6-2. Front Panel Key Codes (continued)
Decimal
Number
LED Pattern
CH1
CH2
R
26
.
.
27
.
.
28
.
.
L
Key
T
.
.
.
.
.
.
.
.
30
.
.
.
.
31
.
.
.
.
32
.
[MEAS]
Response
.
Response
[5]
Entry
[4]
Entry
[softkey 2]
.
33
.
.
.
36
.
.
36
.
.
37
.
.
38
.
.
.
39
.
.
.
Softkey
Entry
[ENTRY OFF]
.
[CENTER]
[softkey 8]
Entry
Stimulus
Softkey
Entry
.
[LOCAL]
.
[softkey 7]
Instrument State
Softkey
Not used
48
.
.
49
.
.
50
.
.
Entry
.
61
.
.
.
.
.
63
.
.
.
54
.
.
.
.
.
Entry
.
52
66
Entry
Stimulus
34
40-47
[M/µ]
[FORMAT]
29
Front Panel Block
S
.
.
[x1]
.
.
.
.
[MKR]
Response
[MKR FCTN]
Response
[.]
Entry
[0]
.
Entry
[softkey 4]
Entry
Softkey
Inspect Cables
Remove the front panel assembly and visually inspect the ribbon cable that
connects the front panel to the motherboard. Also, inspect the interconnecting
ribbon cable between Al and A2. Make sure the cables are properly connected.
Replace any bad cables.
6-10
Digital Control Troubleshooting
Test Using a Controller
If a controller is available, write a simple command to the analyzer. If the
analyzer successfully executes the command, the problem is either the A2 front
panel interface or W17 (A2 to motherboard ribbon cable) is faulty.
Run the Internal Diagnostic Tests
The analyzer incorporates 20 internal diagnostic tests. Most tests can be run as
part of one or both major test sequences: all internal (test 0) and preset (test 1).
1. Press [SYSTEM] [SERVICE MENU] [TESTS] [0] [x1] [EXECUTE TEST] to perform All
INT tests.
2. Then press [1] [x1] to see the results of the preset test. If either sequence
fails, press the [
keys to find the first occurrence of a FAIL message for
tests 2 through 20. See Table 6-3 for further troubleshooting information.
Digital Control Troubleshooting
6-11
Table 6-3. Internal Diagnostic Test with Commentary
Test
Sequence*
Probable Failed Assemblies †;
Comments and Troubleshooting Hints
--
0 All Int
1 Preset
-: Executes tests 3-11, 13-16, 20.
-: Executes tests 2-11, 14-16. Runs at power-on or preset.
2 ROM
P,AI
A9: Repeats on fail; refer to “Check A9 CPU Operation” in this chapter
to replace ROM or A9.
3 CMOS RAM
P,AI
A9: Replace A9.
4 Main DRAM
P,AI
A9: Repeats on fail; replace A9.
5 DSP Wr/Rd
P,AI
A9: Replace A9.
6 DSP RAM
P,AI
A 9 : Replace A9.
7 DSP ALU
P,AI
A 9 : Replace A9.
8 DSP Intrpt
P,AI
A9/A10: Remove A10, rerun test. If fail, replace A9. If pass, replace A10
9 DIF Control
P,AI
A9/A10: Most likely A9 assembly.
10 DIF Counter
P,AI
A10/A9/A12: Check analog bus node 17 for 1 MHz. If correct, A12 is
verified; suspect A10.
11 DSP Control
P,AI
A10/A9: Most likely A10.
12 Fr Pan Wr/Rd
--
A2/A1/A9: Run test 23. If fail, replace A2. If pass, problem is on bus
between A9 and A2 or on A9 assembly.
13 Rear Panel
AI
A16/A9: Disconnect A16, and check A9J2 pin 48 for 4 MHz clock signal.
If OK, replace A16. If not, replace A9.
14 Post-reg
P,AI
16 Frac-N Cont
P,AI
A14: Replace A14.
16 Sweep Trig
P,AI
A14,A10: Most likely A14.
A15/A8/Destination assembly: Refer to the “Power Supply
Troubleshooting” chapter.
17 ADC Lin
--
A10: Replace A10.
18 ADC Ofs
--
A10: Replace A10.
19 ABUS Test
--
A10: Replace A10.
20 FN Count
AI
A14/A13/A10: Most likely Al4 or A13, as previous tests check A10.
Refer to the “Source Troubleshooting” chapter.
*P = part of PRESET sequence; AI -part of ALL INTERNAL sequence.
† in decreasing order of probability.
6-12
Digital Control Troubleshooting
A19 GSP and Al8 Display Troubleshooting
Measure Display Power Supply Voltages on A19
Measure the display power supply voltages on the A19 GSP assembly. Check
pins 2, 4, and 6 on A19J5 for +65 ±0.4 V (see Figure 6-5).
q
If the voltages are incorrect, continue with the next check.
q
If the voltages are correct, go to “Run Display Test 59” later in this chapter.
REAR
W14
A18W1
sh6201c
Figure 6-5. Pin Locations on A19J5
Digital Control Troubleshooting
6-13
Measure Display Power Supply Voltages Entering A19
Measure the power supply voltages entering the Al9 assembly coming from the
A8 assembly. Check pins 1 and 2 on the connector of W14 for +65 ±0.4 V, and
pin 6 for +5.16 ±0.1 V (see Figure 6-6).
If the voltages are incorrect, refer to the “Power Supply Troubleshooting”
chapter.
If the voltages are correct entering, but incorrect leaving the GSP assembly,
replace the A19 GSP assembly.
A18W1
PINS ON CONNECTOR OF W14
Figure 6-6. Pin Locations on Connector of W14
6-14
Digital Control Troubleshooting
Run Display Test 59
1. On the analyzer, press [PRESET] [SYSTEM] [SERVICE MENU] (softkey 8) [TESTS]
(softkey 1) [DISPLAY TESTS] (softkey 7). The analyzer will display:
TEST
59 Disp/cpu corn -ND2. Press [EXECUTE TEST] (softkey 8). The display will blank and the front panel
LEDs will flash once.
q
If all of the LEDs go off and the display remains blank the analyzer passed
the test. If the analyzer passes the test, press [PRESET] and go to "Run
display Tests 60-65".
q
If any of the front panel LEDs remain on (except for the port LEDs), the
analyzer failed the test. Continue with the next check.
Inspect Ribbon Cable Repeat Display Test 59
1. Inspect the W20 (A9-A19) ribbon cable for a loose connection.
2. Repeat “Run Display test 59.” If the test fails, a walking one pattern will be
continuously transferred from the CPU, through the cable, to the GSP.
3. Immediately go to the next check.
Digital Control Troubleshooting
6-15
Perform Walking One Pattern
1. Disconnect the W20 (A9-A19) ribbon cable from A19J6.
2. Use an oscilloscope to verify a walking one pattern is transferring from
the A9 CPU through the cable. The walking one pattern (see Figure 6-7) is
found on pins 3 through 10, and 13 through 20 on the connector of W20 (see
Figure 6-8).
q
q
If the signal is not present at the end of the cable, check for it at the A9
connector of the ribbon cable.
If the signal is still not present, replace the A9 assembly.
sg601s
Figure 6-7. A9 CPU Walking One Pattern
6-16
Digital Control Troubleshooting
W20
REAR
Figure 6-8. Pin Locations on Connector of W20
Run display Tests 60-66
1. Press [PRESET] [SYSTEM] [SERVICE MENU] (softkey 8) [TESTS] (softkey 1)
[DISPLAY TESTS] (softkey 7) [60] [x1].
2. Press [EXECUTE TEST] (softkey 8). If the analyzer passes the test, the display
will blank and the front panel LEDs will flash once.
3. Press [PRESET] and perform display tests 61 through 65 (substitute the next
test number where [60] was used). Watch for the LEDs to go off and the
display to blank except for test 65. Test 65 causes the display to dim rather
than blank.
•
•
If any of the display tests fail, replace the A19 assembly.
If all of the following is true, replace the Al8 display assembly.
CPU test passes the LED test.
GSP passes all of the internal display tests (59 through 65).
Power supply checks out.
Intensity, focus, and vertical adjustments fail to produce an acceptable
image.
Digital Control Troubleshooting
6-17
If the Fault is Intermittent
Repeat Test Function
If the failure is intermittent, do the following:
1. Press [SYSTEM] [SERVICE MENU] [TEST OPTIONS] [REPEAT ON] to activate the
repeat function.
2. Then press [RETURN TESTS].
3. Select the desired test and press [EXECUTE TEST].
4. Press [PRESET] to stop the function. The test repeat function is explained in
the “Service Key Menus and Error Messages” chapter.
HP-IB Failures
If you have performed “Step 3. Troubleshooting HP-IB Systems” in the “Start
Troubleshooting Here” chapter, and you suspect there is an HP-IB problem in
the analyzer, perform the following test. It checks the internal communication
path between the A9 CPU and the Al6 rear panel. It does not check the HP-IB
paths external to the analyzer.
Press [SYSTEM] [SERVICE MENU] [TESTS] [13] [x1] [EXECUTE TEST].
• If the analyzer fails the test, the problem is likely to be the A16 rear panel.
• If the analyzer passes the test, it indicates that the A9 CPU can communicate
with the Al6 rear panel with a 50% confidence level. There is a good chance
that the Al6 rear panel is working. This is because internal bus lines have
been tested between the A9 CPU and A16, and HP-IB signal paths are not
checked external to the analyzer.
6-16
Digital Control Troubleshooting
Source Troubleshooting
Use this procedure only if you have read the “Start Troubleshooting Here”
chapter. This chapter is divided into two troubleshooting procedures for the
following problems:
n
Incorrect power levels: Perform the “Power” troubleshooting checks.
n
Phase lock error: Perform the “Phase Lock Error” troubleshooting checks.
The source group assemblies consist of the following:
n
A3 source
n
-
A4 sampler/mixer
n
A7 pulse generator
n
n
All phase lock
Al2 reference
Al3 fractional-N (analog)
Al4 fractional-N (digital)
Source Troubleshooting
7-1
Assembly Replacement Sequence
The following steps show the sequence to replace an assembly in an HP 8752C
Network Analyzer.
1. Identify the faulty group. Refer to the “Start Troubleshooting Here” chapter.
Follow up with the appropriate troubleshooting chapter that identifies the
faulty assembly.
2. Order a replacement assembly. Refer to the “Replaceable Parts” chapter.
3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to the “Assembly Replacement and Post-Repair Procedures” chapter.
4. Perform the necessary adjustments. Refer to the “Adjustments and
Correction Constants” chapter.
5. Perform the necessary performance tests. Refer to the “System Verification
and Performance Tests” chapter.
Before You Start Troubleshooting
Make sure all of the assemblies are firmly seated. Also make sure that input R
has a signal of at least -35 dBm (about 0.01 Vp-p into 50 ohms) at all times to
maintain phase lock.
7-2
Source Troubleshooting
Power
If the analyzer output power levels are incorrect but no phase lock error is
present, perform the following checks in the order given:
1. Source Default Correction Constants (Test 44)
1. Press [PRESET] [SYSTEM] [SERVICE MENU] [TESTS] [44] [x1] [EXECUTE TEST].
When complete, “DONE” should appear on the analyzer display.
2. Use a power meter to verify that source power can be controlled and that
the power level is approximately correct.
q
q
If the source passes these checks, proceed with step 2.
If “FAIL” appears on the analyzer display, or if the analyzer fails the
checks, replace the source.
2. RF Output Power Correction Constants (Test 47)
1. Follow the instructions for this procedure given in the “Adjustments and
Correction Constants” chapter. The procedure is complete when “DONE”
appears on the analyzer display.
2. Use a power meter to verify that power levels are now correct.
q
If power levels are incorrect, or if the analyzer fails the routine, proceed
with step 3.
3. Sampler Magnitude and Phase Correction Constants
(Test 53)
1. Follow the instructions for this procedure given in the “Adjustments and
Correction Constants” chapter. The procedure is complete when “DONE”
appears on the analyzer display.
2. Repeat step 2.
q
If the analyzer fails the routine in step 2, replace the source.
q
If the analyzer fails the routine in step 3, replace the source.
Source Troubleshooting
7-3
Phase Lock Error
OSC I L LOSCOPE
Figure 7-l. Phase Lock Error Troubleshooting Equipment Setup
Troubleshooting tools include the assembly location diagram and phase lock
diagnostic tools. The assembly location diagram is on the underside of the
instrument top cover. The diagram shows major assembly locations and RF cable
connections. The phase lock diagnostic tools are explained in the “Source Group
Troubleshooting Appendix” and should be used to troubleshoot phase lock
problems. The equipment setup shown in Figure 7-l can be used throughout this
chapter.
Phase Lock Loop Error Message Check
Phase lock error messages may appear as a result of incorrect pretune
correction constants. To check this possibility, perform the pretune correction
constants routine.
The four phase lock error messages, listed below, are described in the “Source
Group Troubleshooting Appendix” at the end of this chapter.
n
NO IF FOUND: CHECKR INPUT LEVEL
n
NO PHASELOCK: CHECKR INPUT LEVEL
n
PHASE LOCK CAL FAILED
n
PHASE LOCK LOST
7-4
Source Troubleshooting
1. Make sure the A9 CC Jumper is in the ALTER position:
a. Unplug the analyzer.
b. Remove the top cover.
c. Remove the A9 CPU board.
d. Move the jumper to the ALT position. (Refer to Figure 7-2.)
e. Replace the A9 CPU board, top cover, and power cord.
HP 8752 A9CPU Assembly
NRM
(Normal)
ALT
(Alter)
Figure 7-2. Jumper Positions on the A9 CPU
Source Troubleshooting
7-5
2. Switch on the analyzer and press [PRESET] [SYSTEM] [SERVICE MENU] [TESTS]
[EXECUTE TEST] [YES] to generate new analog bus correction
constants.
[46] [x1]
3. Then press [PRESET] [SYSTEM] [SERVICE MENU] [TESTS] [45] [x1] [EXECUTE TEST]
[YES] to generate new pretune correction constants.
4. Press [PRESET] [SYSTEM] [SERVICE MENU] [TESTS] [48] [x1] [EXECUTE TEST] [YES]
to generate new pretune correction constants.
Note
Always press [PRESET] before and after performing an
adjustment test.
5. Press [PRESET] and observe the analyzer display:
q
q
If no error message is displayed: restore the A9 CC jumper to the NRM
position. Then refer to “Post-Repair Procedures” in the “Assembly
Replacement and Post-Repair Procedures” chapter to verify operation.
If an error message is displayed: continue with “A4 Sampler/Mixer Check.”
A4 Sampler/Mixer Check
The A4, A5, and A6 (R, A and B) sampler/mixers are similar in operation. Any
sampler can be used to phase lock the source. To eliminate the possibility of a
faulty R sampler, follow this procedure.
1. Remove the W8 cable (A11J1 to A4) from the R-channel sampler (A4) and
connect it to either the A-channel sampler (A5) or the B-channel sampler
(A6). Refer to Figure 7-3.
7-6
Source Troubleshooting
A1 1
TOP RIGHT FRONT
A4
W8
A5
Figure 7-3. Sampler/Mixer to Phase Lock Cable Connection Diagram
2. If you connected W8 to:
• A5, press [MEAS] [RELECTION]
• A6, connect a cable between the reflection and transmission test ports and
press [MEAS] [TRANSMISSN]
3. Ignore the displayed trace, but check for phase lock error messages. If the
phase lock problem persists, the R-channel sampler is not the problem.
Source Troubleshooting
7-7
A3 Source and All Phase Lock Check
This procedure checks the source and part of the phase lock assembly. It opens
the phase-locked loop and exercises the source by varying the source output
frequency with the All pretune DAC.
Note
If the analyzer failed internal test 48, default pretune correction
constants were stored which may result in a constant offset of
several MHz. Regardless, continue with this procedure.
Note
Use a spectrum analyzer for problems above 100 MHz.
1. Connect the oscilloscope or spectrum analyzer as shown in Figure 7-1. (Set
the oscilloscope input impedance to 50 ohms.)
2. Press [PRESET] [SYSTEM] [SERVICE MENU] [SERVICE MODES] [SRC ADJUST MENU]
[SRC TUNE ON] [SRC TUNE FREQ] to activate the source tune (SRC TUNE)
service mode.
3. Use the front panel knob or front panel keys to set the pretune frequency
to 300 kHz, 30 MHz, and 40 MHz. Verify the signal frequency on the
oscilloscope.
Note
In SRC TUNE mode, the source output frequency changes in
1 to 2 MHz increments and should be 1 to 6 MHz above the
indicated output frequency.
4. Check for the frequencies indicated by Table 7-l.
Table 7-1. Output Frequency in SRC Tune Mode
Setting
300 kHz
7-8
Observed
Frequency
1.3 to 6.3 MHz
30 MHz
31 to 36 MHz
40 MHz
41 too46 MHz
Source Troubleshooting
5. The signal observed on an oscilloscope should be as solid as the signal in
Figure 7-4.
0.00000 sec
-50. 000 nsec
Ch. 1
=
100.0 mvolts/dlv
Timebase = 10.0 nsec/div
50.000
Offset
Delay
=
=
nsec
4.000 mvolts
0.00000 sec
sg607s
Figure 7-4. Waveform Integrity in SRC Tune Mode
6. The signal observed on the spectrum analyzer will appear jittery as in
Figure 7-5b, not solid as in Figure 7-5a. This is because in SRC TUNE mode
the output is not phase locked.
a
Figure 7-5.
Phase Locked Output Compared to Open Loop Output in SRC Tune Mode
Source Troubleshooting
7-9
7. Press [MENU] [POWER] to vary the power and check for corresponding level
changes on the test instrument. (A power change of 20 dB will change the
voltage observed on the oscilloscope by a factor of ten.)
8. Note the results of the frequency and power changes:
q
If the frequency and power output changes are correct, continue with
“Al2 Reference Check” located in this chapter.
q
If the frequency changes are incorrect, continue with "YO Coil Drive Check
with Analog Bus."
q
If the power output changes are incorrect, check analog bus node 3.
a. Press [SYSTEM] [SERVICE MENU] [ANALOG BUS ON] [MEAS]
[ANALOG IN Aux Input] [FORMAT] [MORE REAL] [3] [x1].
b. Press [MARKER] [2] [G/n]. The marker should read approximately 434 mU.
c. Press [MARKER] [4] [G/n]. The marker should read approximately 646 mU.
7-10
Source Troubleshooting
YO Coil Drive Check with Analog Bus
Note
If the analog bus is not functional, perform the “YO Drive Coil
Check with Oscilloscope” procedure.
Press [PRESET] [SYSTEM] [SERVICE MENU] [ANALOG BUS ON] [SERVICE MODES]
[SOURCE PLL OFF] [MEAS] [ANALOG IN Aux Input] [COUNTER: ANALOG BUS].
Then press [16] [x1] [FORMAT] [MORE] [REAL] [SCALE REF] [AUTOSCALE]. This
keystroke sequence lets you check the pretune DAC and the All output to
the YO coil drive by monitoring the 1V/GHz signal at analog bus node 16.
Compare the waveform to Figure 7-6. If the waveform is incorrect, the All
phase lock assembly is faulty.
START
.300 000 MHz
STOP 6
000.000 000 MHz
6 GHz 8752C
sh6116c
Figure 7-6. 1V/GHz at Analog Bus Node 16 with Source PLL Off.
Source Troubleshooting
7-11
YO Coil Drive Check with Oscilloscope
Note
Use the large extender board for easy access to the voltage
points. The extender board is included with the HP 8753 Tool
Kit. See the “Replaceable Parts” chapter for part numbers and
ordering information.
1. Connect oscilloscope probes to A11P1-1 and A11P1-2. The YO coil drive
signal is actually two signals whose voltage difference drives the coil.
2. Press [PRESET] [SYSTEM] [SERVICE MENU] [SERVICE MODES] [SOURCE PLL OFF] to
operate the analyzer in a swept open loop mode.
3. Monitor the two YO coil drive lines. In source tune mode the voltage
difference should vary from approximately 3.5 to 5.0 volts as shown in
Figure 7-7.
q
If the voltages are incorrect, replace the faulty All assembly.
q
If the voltages are correct, replace the faulty A3 source assembly.
q
If neither the Al 1, nor the A3 assembly is faulty, continue with the next
check.
Ch. 1
Ch. 2
Timbase
=
=
=
1.000 volts/div
1.000 volts/div
30.0 ms/div
Offset
Offset
Delay
=
=
=
7.000 volts
7.000 volts
0. 00000 s
Figure 7-7.
YO- and YO + Coil Drive Voltage Differences with SOURCE PLL OFF
7-12
Source Troubleshooting
Al2 Reference Check
The signals are evaluated with pass/fail checks. The most efficient way to check
the A12 frequency reference signals is to use the analog bus while referring to
Table 7-2.
Alternatively, you can use an oscilloscope, while referring to Table 7-3 and
Figure 7-8 through Figure 7-14. If any of the observed signals differs from
the figures, there is a 90% probability that the Al2 assembly is faulty. Either
consider the A12 assembly defective or perform the "A12 Digital Control Signals
Check."
Both of these procedures are described next.
Analog Bus Method
1. Press [PRESET] [SYSTEM] [SERVICE MENU] [ANALOG BUS UN] [MEAS]
[ANALOG IN Aux Input] [ANALOG BUS] to switch on the analog bus and its
counter.
2. Press [21] [x1] to count the frequency of the 100 kHz signal.
3. Press [MENU] [CW FREQ] [500] [k/m] Verify that the counter reading (displayed
on the analyzer next to cnt :) matches the corresponding 100 kHz value for
the CW frequency. (Refer to Table 7-2.)
4. Verify the remaining CW frequencies, comparing the counter reading with
the value in Table 7-2:
a. Press [2] [M/µ]
b. Press [50] [M/µ].
Table 7-2. Analog Bus Check of Reference Frequencies
CW Frequency
Analog Bus Node 21
100 kHz
Analog Bus Node 24
2nd LO
Analog Bus Node 25
PLREG
500 kHz
0.100 MHz
0.604 MHz
0.600 MHz
2 MHz
0.100 MHz
2.007 MHz
2.000 MHz
50 MHz
0.100 MHz
0.996 MHz
1.000 MHz
NOTE: The counter should indicate the frequencies listed in this table to within ±0.1%. Accuracy may vary
with gate time and signal strength.
Source Troubleshooting
7-13
5. Press [24] [x1] to count the frequency of the 2nd LO signal.
6. Press [MENU] [CW FREQ] [500] [k/m]. Verify that the counter reading matches
the corresponding 2nd LO value for the CW frequency. (Refer to Table 7-2.)
7. Verify the remaining CW frequencies, comparing the counter reading with
the value in Table 7-2:
a. Press [2] [M/µ].
b. Press [50] [M/µ].
8. Press [25] [x1] to count the frequency of the PLREF signal.
9. Press [MENU] [CW FREQ] [500] [k/m]. Verify that the counter reading matches
the corresponding PLREF value for the CW frequency. (Refer to Table 7-2.)
10. Verify the remaining CW frequencies, comparing the counter reading with
the value in Table 7-2:
a. Press [2] [M/µ].
b. Press [50] [M/µ].
11. Check the results.
q
If all the counter readings match the frequencies listed in Table 7-2,
continue with "A13/A14 Fractional-N Check."
q
If the counter readings are incorrect at the 500 kHz and 2 MHz settings
only, continue with “FN LO at Al2 Check.”
q
7-14
If all the counter readings are incorrect at all three CW frequencies, the
counter may be faulty. Perform the “Oscilloscope Method” check of the
signals described below. (If the signals are correct, either the A10 or Al4
assemblies could be faulty.)
Source Troubleshooting
Oscilloscope Method
You need not use the oscilloscope method unless the analog bus is
non-functional or any of the signals fail the specifications listed in Table 7-2.
If the analog bus is non-functional or the previous check has revealed
questionable signals, observe the signal(s) with an oscilloscope. Table 7-3
identifies convenient test points and figures showing the five signals listed.
Table 7-3. Al2 Reference Frequencies
Mnemonic
FN100kHzREF
REF
REF
Signal
Description
Test Point
Location
Figure
100 kHz Reference
A13TP5
Figure 7-8
Phase Lock
Reference
Phase Lock
Reference
Analyzer
Setting
AllTPl PIN 9
Figure 7-9
> or = 16 MHz CW
AllTPl PIN 9
Figure 7- 10
6 MHz CW
FN LO*
Fractional-N LO
A14J2
Figure 7-11
10 MHz CW
4MHz REF
4 MHz Reference
A12TP9
Figure 7-12
any
2ND LO +/-
Second LO
A12P1-2,4
Figure 7-13
2ND LO +/-
Second LO
A12P1-2,4
Figure 7-14
> or = 16 MHz CW
14 MHz CW
* not an A12 signal, but required for Al2 lowband operation.
Source Troubleshooting
7-15
100 kHz Pulses
The 100 kHz pulses are very narrow and typically 1.5V in amplitude. You may
have to increase the oscilloscope intensity to see these pulses. (See Figure 7-8.)
-100.000 us
Ch. 1
=
Timebase =
0.00000
1.000 volts/div
20.0 us/div
s
100.000 us
Offset
Delay
= 0.000 volts
= 0.00000 s
sg610s
Figure 7-8. Sharp 100 kHz Pulses at A13TP5 (any frequency)
7-16
Source Troubleshooting
PLREF Waveforms
REF Signal At A11TP1 PIN 9. REF is the buffered PLREF+ signal. The 1st IF
is phase locked to this signal. Use an oscilloscope to observe the signal at the
frequencies noted in Figure 7-9 and Figure 7-10.
High Hand REF Signal. In high band the REF signal is a constant 1 MHz square
wave as indicated by Figure 7-9.
-1.00000 us
Ch. 1
Timebase
0.00000 s
=
=
500.0 mvolts/div
200 ns/div
1.00000 us
Offset
Delay
=
=
0.000 volts
0.00000 s
sg611s
Figure 7-9. High Hand REF Signal (> or = 16 MHz CW)
Source Troubleshooting
7-17
Low Band REF Signal. In low band this signal follows the frequency of the RF
output signal. Figure 7-10 illustrates a 5 MHz CW signal.
0. 00000 s
Ch. 1
Timebase
= 500.0 mvolts/div
= 200 ns/div
Offset
Delay
=
=
0.000 volts
0.00000 s
sg612s
Figure 7-10. REF Signal at A11TP9 (5 MHz CW)
• If REF looks correct, continue with “4 MHz Reference Signal.”
• If REF is incorrect in low band, continue with “FN LO at Al2 Check.”
7-18
Source Troubleshooting
FN LO at A12 Check
1. Use an oscilloscope to observe the FN LO from Al4 at the cable end
of A14J2. Press [PRESET] [SYSTEM] [SERVICE MENU] [SERVICE MODES]
[FRACN TUNE ON] to switch on the fractional-N service mode.
2. Use the front panel knob to vary the frequency from 30 to 60 MHz. The
signal should appear similar to Figure 7-11. The display will indicate 10 to
60.8 MHz.
q
q
If the FN LO signal is correct, the Al2 assembly is faulty.
If the FN LO signal is incorrect, continue with "A13/A14 Fractional-N
Check. "
-50. 000 nsec
Ch. 2
Timebase
=
=
0.00000 sec
100.0 mvolts/div
10.0 nsec/div
Offset
Delay
=
=
0.000 volts
0.00000 sec
sg613s
Figure 7-11. Typical FN LO Waveform at A12J1
Source Troubleshooting
7-19
4 MHz Reference Signal
This reference signal is used to control the receiver. If faulty, this signal can
cause apparent source problems because the CPU uses receiver data to control
the source. At A12TP9 it should appear similar to Figure 7-12.
-500.000 nsec
Ch. 1 = 1.000 volts/div
Timebase = 100 nsec/div
0.00000 sec
500.000 nsec
Offset = 0.000 volts
Delay = 0.00000 sec
sg614s
Figure 7-12. 4 MHz Reference Signal at A12TP9 (Preset)
7-20
Source Troubleshooting
2ND LO Waveforms
The 2nd LO signals appear different in phase and shape at different frequencies.
Refer to Table 7-3 for convenient test points.
90 Degree Phase Offset of 2nd LO Signals in High Band. In high band, the
2nd LO is 996 kHz. As indicated by Figure 7-13, the 2nd LO actually consists of
two signals 90 degrees out of phase.
-1.00000 usec
Ch. 1 = 200.0 mvolts/div
Ch. 2 = 200.0 mvolts/div
Timebase = 200 nsec/div
0.00000
sec
1.00000 usec
Offset = 0.000 volts
Offset = 0.000 volts
Delay = 0.00000 sec
sg615s
Figure 7-13.
90 Degree Phase Offset of High Band 2nd LO Signals (> or = 16 MHz CW)
Source Troubleshooting
7-21
In-Phase 2nd LO Signals in Low Band. The 2nd LO signals in low band, as
shown in Figure 7-14, are not phase shifted. In low band these signals track the
RF output with a 4 kHz offset.
-100. 000 nsec
0.00000
sec
100.000 nsec
sg616s
Figure 7-14. In-Phase Low Band 2nd LO Signals (14 MHz CW)
If any of the signals of Table 7-2 are incorrect, the probability is 90% that the
Al2 assembly is faulty. Either consider the Al2 assembly faulty or perform the
“Al2 Digital Control Signals Check” described next.
7-22
Source Troubleshooting
Al2 Digital Control Signals Check
Several digital control signals must be functional for the Al2 assembly
to operate correctly. Check the control lines listed in Table 7-4 with the
oscilloscope in the high input impedance setting.
Table 7-4. A12-Related Digital Control Signals
Mnemonic
Signal
Description
Location
See
Figure
Analyzer
Setting
L ENREF
L-Reference Enable
A12P2-16
Figure 7-15
Preset
LHB
L = High Band
A12P2-32
Figure 7-16
Preset
LLB
L = Low Band
A12P1-23
Figure 7-16
Preset
L ENREF Line. This is a TTL signal. To observe it, trigger on the negative edge.
In preset state, the signal should show activity similar to Figure 7-15.
Ch. 2 = 2.000 volts/div
Timebase = 1.00 usec/div
= 5.000 volts
= 0.00000 sec
sg617s
Figure 7-15. L ENREF Line at A12P2-16 (Preset)
Source Troubleshooting
7-23
L HB and L LB Lines. These complementary signals toggle when the instrument
switches from low band to high band as illustrated by Figure 7-16.
Timebase =1000 msec/div
sg618s
Figure 7-16. Complementary L HB and L LB Signals (Preset)
If all of the digital signals appeared correct, the Al2 assembly is faulty.
A13 / A14 Fractional-N Check
Use the analog bus or an oscilloscope to check the Al4 VCO's ability to sweep
from 30 MHz to 60 MHz. The faster analog bus method should suffice unless
problems are detected.
Fractional-N Check with Analog Bus
1. Press [PRESET] [SYSTEM] [SERVICE MENU][ANALOG BUS ON] [MEAS]
[ANALOG IN Aux Input] [FRAC N] to switch on the analog bus and the
fractional-N counter.
2. Then press [MENU] [CW FREQ] to set the analyzer to CW mode.
3. Set the instrument as indicated in Table 7-5 and see whether the VCO
generates the frequencies listed.
7-24
Source Troubleshooting
Table 7-5. VCO Range Check Frequencies
Instrument Setting
31 MHz
60.999999 MHz
Counter Reading
30±0.030 MHz
60±0.060 MHz
4. Check the counter reading at the frequencies indicated.
q
q
If the readings are within the limits specified, the probability is greater
than 90% that the fractional-N assemblies are functional. Either continue
with the “A7 Pulse Generator Check” or perform the more conclusive “Al4
VCO Range Check with Oscilloscope” described below.
If the readings fail the specified limits, perform the “A14 VCO Exercise.”
Source Troubleshooting
7-25
Al4 VCO Range Check with Oscilloscope
1. Remove the W9 HI OUT cable (A14J1 to A7) from the A7 assembly and
connect it to an oscilloscope set for 50 ohm input impedance. Switch on the
analyzer.
2. Press [PRESET] [SYSTEM] [SERVICE MENU] [SERVICE MODES] FRACN TUNE ON] to
activate the FRACN TUNE service mode. See the “Service Key Menus and
Error Messages” chapter for more information on the FRACN TUNE mode.
3. Vary the fractional-N VCO frequency with the front panel knob and check
the signal with the oscilloscope. The waveform should resemble Figure 7-17,
Figure 7-18, and Figure 7-19.
If the fractional-N output signals are correct, continue source troubleshooting
by continuing with “A7 Pulse Generator Check.”
-50.000
nsec
0.00000
sec
50.000
nsec
sg619s
Figure 7-17. 10 MHz HI OUT Waveform from A14J1
7-26
Source Troubleshooting
Ch. 2 = 100.0 mvolts/div
Timebase = 10. 0 nsec/div
Offset = 0.000 volts
Delay = 0. 00000 sec
sg620s
Figure 7-18. 25 MHz HI OUT Waveform from A14J1
-50. 000 nsec
Ch. 2 = 100.0 mvolts/div
Timebase =10.0 nsec/div
0.00000
sec
50.000
nsec
Offset = 0.000 volts
Delay = 0.00000 sec
sg621s
Figure 7-19. 60 MHz HI OUT Waveform from A14J1
Source Troubleshooting
7-27
Al4 VCO Exercise
The nominal tuning voltage range of the VCO is + 10 to -5 volts. When the
analyzer is in operation, this voltage is supplied by the Al3 assembly. This
procedure substitutes a power supply for the Al3 assembly to check the
frequency range of the Al4 VCO.
1. Switch off the analyzer and remove the Al3 assembly.
--
2. Put the A14 assembly on an extender board and switch on the instrument.
3. Prepare to monitor the VCO frequency, either by:
Activating the analog bus and setting the internal counter to the FRACN
node, or
Connecting an oscilloscope to A14J2 (labeled LO OUT) and looking for
waveforms similar to Figure 7-20.
-50.000 nsec
0.00000 sec
Ch. 2 = 100.0 mvolts/div
Timebase 10.0 nsec/div
50.000 nsec
Offset = 0.000 volts
Delay = 0.00000 sec
sg613s
Figure 7-20. LO OUT Waveform at A14J2
4. Vary the voltage at A14TP14 from + 10 to -5 volts either by:
n
n
7-28
Connecting an appropriate external power supply to A14TP14, or
First jumping the + 15V internal power supply from A8TP8 to A14TP14 and
then jumping the -5.2V supply from A8TP10 to A14TP14.
Source Troubleshooting
5. Confirm that the VCO frequency changes from approximately 30 MHz or less
to 60 MHz or more.
6. If this procedure produces unexpected results, the Al4 assembly is faulty.
7. If this procedure produces the expected results, continue with the "Al4
Divide-by-N Circuit Check."
Al4 Divide-by-N Circuit Check
Note
The Al3 assembly should still be out of the instrument and the
Al4 assembly on an extender board.
1. Ground A14TP14 and confirm (as in the Al4 VCO Exercise) that the VCO
oscillates at approximately 50 to 55 MHz.
2. Put the analyzer in CW mode (to avoid relock transitions) and activate the
FRACN TUNE service mode.
3. Connect an oscilloscope to A14J3 and observe the output.
4. With the FRACN TUNE service feature, vary the frequency from 30 MHz to
60.8 MHz.
5. The period of the observed signal should vary from 5.5 µs to 11 µs.
q
q
If this procedure produces unexpected results, the Al4 assembly is faulty.
If this procedure produces the expected results, perform the "A14-to-A13
Digital Control Signals Check."
6. Remember to replace the Al3 assembly.
Source Troubleshooting
7-29
A14-to-A13 Digital Control Signals Check.
The Al4 assembly generates a TTL cycle start (CST) signal every 10
microseconds. If the VCO is oscillating and the CST signal is not detectable at
A14TP3, the Al4 assembly is non-functional.
Use the CST signal as an external trigger for the oscilloscope and monitor the
signals in Table 7-6. Since these TTL signals are generated by Al4 to control
A13, check them at Al3 first. Place Al3 on the large extender board. The
signals should look similar to Figure 7-21. If these signals are correct, the Al3
assembly is defective.
Table 7-6. A14-to-A13 Digital Control Signal Locations
Mnemonic
Al4 Location
CST
none
TP3
L FNHOLD
P2-2
P2-2
FNBIAS
API1
7-30
Al3 Location
P2-5
P2-32
P2-5
P2-32
API2
P2-3
P2-3
API3
P2-34
P2-34
API4
P2-4
P2-4
API5
P2-35
P2-35
NLATCH
Pl-28
P1-58
Source Troubleshooting
CST
L FNHOLO
FN BIAS
APl1-5
FN LATCH
Figure 7-2 1. Al4 Generated Digital Control Signals
Source Troubleshooting
7-31
H MB Line. This signal is active during the 16 MHz to 31 MHz sweep. The
upper trace of Figure 7-22 shows relative inactivity of this signal during preset
condition. The lower trace shows its status during a 16 MHz to 31 MHz sweep
with inactivity during retrace only.
-1.00000
sec
0.00000
sec
1.00000
sec
Figure 7-22.
H MB Signal at A14P1-5 (Preset and 16 MHz to 31 MHz Sweep)
7-32
Source Troubleshooting
A7 Pulse Generator Check
The pulse generator affects phase lock in high band only. It can be checked with
either a spectrum analyzer or an oscilloscope.
A7 Pulse Generator Check with Spectrum Analyzer
1. Remove the A7-to-A6 SMB cable (W7) from the A7 pulse generator assembly.
Set the analyzer to generate a 16 MHz CW signal. Connect the spectrum
analyzer to the A7 output connector and observe the signal. The A7 comb
should resemble the spectral display in Figure 7-23.
0 Hz
RES BW 10 kHz
VBW 10 kHz
STOP 2. 50 GHz
SWP 75. 0 sec
sg624s
Figure 7-23. Pulse Generator Output
Source Troubleshooting
7-33
2. If the analyzer malfunction relates to a particular frequency or range, look
more closely at the comb tooth there. Adjust the spectrum analyzer span
and bandwidth as required. Even at 3 GHz, the comb should look as clean
as Figure 7-24. For Option 006 instruments at 6 GHz the comb tooth level
should be approximately -46 dBm.
sg625s
Figure 7-24. High Quality Comb Tooth at 3 GHz
3. If the signal at the A7 output is correct, check the A7-to-A4 cable.
4. If the signal is not as clean as Figure 7-24, observe the HI OUT input signal to
the A7 assembly.
a. On the network analyzer, press [SYSTEM] [SERVICE MENU] [SERVICE MODES]
[PLL AUTO OFF]. Otherwise do not readjust the instrument. Remove
the A14-to-A7 SMB cable (W9) from the A7 pulse generator assembly.
~ 16 MHz).
(CW ~
b. Set the spectrum analyzer to a center frequency of 45 MHz and a span
of 30 MHz. Connect it to the A14-to-A7 cable still attached to the Al4
assembly. Narrow the span and bandwidth to observe the signal closely.
5. If the HI OUT signal is as clean as Figure 7-25, the A7 assembly is faulty.
Otherwise, check the A14-to-A7 cable or recheck the A13/A14 fractional-N as
described ahead.
7-34
Source Troubleshooting
Rechecking the A13/A14 Fractional-N
Some phase lock problems may result from phase noise problems in the
fractional-N loop. To troubleshoot this unusual failure mode, do the following:
1. Set the network analyzer at 60 MHz in the FRACN TUNE mode.
2. Use a spectrum analyzer, to examine the HI OUT signal from the A14
assembly. The signal should appear as clean as Figure 7-25. The comb shape
may vary from pulse generator to pulse generator.
sg626s
Figure 7-25. Stable HI OUT Signal in FRACN TUNE Mode
A7 Pulse Generator Check with Oscilloscope
Perform this check if a spectrum analyzer is not available.
1. Remove the A4-to-A11 SMB cable from the A4 (R) sampler/mixer output.
Connect the oscilloscope to the A4 output (1st IF).
2. Activate the FRACN TUNE service mode and tune the fractional-N to
50 MHz. Press [SYSTEM] [SERVICE MENU] [SERVICE MODES] [FRACN TUNE ON] [50]
[M/µ]
3. Activate the SRC TUNE service mode of the analyzer and tune the source to
50 MHz. Press [SRC TUNE ON] [SRC TUNE FREQ] [50] [M/µ].
Source Troubleshooting
7-35
4. Set the SRC TUNE frequency to those listed in Table 7-7 and observe the 1st
IF waveforms. They should appear similar to Figure 7-26.
q
q
If the signals observed are correct, continue with “All Phase Lock Check.”
If the signals observed are questionable, use a spectrum analyzer to
perform the preceding “A7 Pulse Generator Check with Spectrum
Analyzer.”
Table 7-7. 1st IF Waveform Settings
SRC TUNE
FRACN
50 MHZ
50MHz
1
1 to 6 MHz
250 MHz
50MHz
5
1 to 6 MHz
2550 MHz
50MHz
51
-1.00000 us
Harmonic
0.00000 s
1st IF
1 to 6 MHz
1.00000 us
sg627s
Figure 7-26. Typical 1st IF Waveform in FRACN TUNE/SRC TUNE Mode
7-36
Source Troubleshooting
All Phase Lock Check
At this point, the All phase lock assembly appears to be faulty (its inputs
should have been verified already). Nevertheless, you may elect to use the
phase lock diagnostic routines or check the relevant signals at the assembly
itself for confirmation.
Note
If external source mode is the only operating mode with phase
lock problems, replace the All phase lock assembly.
Phase Lock Check with PLL DIAG
Refer to “Phase Lock Diagnostic Tools” in “Source Group Troubleshooting
Appendix” at the end of this chapter for an explanation of the error messages
and the diagnostic routines. Follow the steps there to determine in which state
the phase lock is lost.
q
q
q
If NO IF FOUND is displayed, confirm that the analog bus is functional and
perform the “Source Pretune Correction Constants (Test 48)” as outlined in
the “Adjustments and Correction Constants” chapter.
If phase lock is lost in the ACQUIRE state, the All assembly is faulty.
If phase lock is lost in the TRACK state, troubleshoot source phase lock loop
components other than the All assembly.
Phase Lock Check by Signal Examination
To confirm that the All assembly is receiving the signals required for its
operation, perform the following steps.
1. Place the A11 assembly on the large extender board.
2. Switch on the analyzer and press [PRESET]
3. Check for the signals listed in Table 7-8.
Source Troubleshooting
7-37
Table 7-8. All Input Signals
Mnemonic
FM COIL –
I/O
O
Access
A11P1-3,33
See
Figure
Figure 7-27
Notes
Aids YO COIL in setting YIG. Press [PRESET] [MENU]
NUMBER OF POINTS [3] [x1] to observe this signal.
REF
I
A11TP9
YO COIL +
O
A11P1-2,32
YO COIL –
O
A11P1-1,31
1ST IF
I
All PL IF IN
-1.00000 s
Figure 7-9,
Figure 7-10
Figure 7-7
Observe both low band and high band CW frequencies.
Use SOURCE PLL OFF.
Figure 7-7
Figure 7-26 Check for 1 MHz with tee a All jack (not at cable end) in
high band.
-500.000 ms
Ch. 1 = 2.000 volts/div
Timebasee = 100 ms/div
0.00000 s
Offset =0.000 volts
Delay = 0.00000 s
sg628s
Figure 7-27. FM Coil – Plot with 3 Point Sweep
4. If any of the input signal is not correct, refer to the overall block diagram in
the “Start Troubleshooting Here”chapter as an aid to trouble shooting the
problem to its source.
5. If any of the output signals are incorrect, the All assembly is faulty.
7-38
Source Troubleshooting
Source Group Troubleshooting Appendix
Troubleshooting Source Problems with the Analog Bus
The analog bus can perform a variety of fast checks. However, it too is subject
to failure and should be tested prior to use. You should have done this in the
“Start Troubleshooting Here” chapter.
To use the analog bus to check any one of the nodes, press [PRESET] [SYSTEM]
[SERVICE MENU] [ANALOG BUS ON]. Then press [MEAS] [ANALOG IN Aux Input]
and enter the analog bus node number followed by [x1]. Refer to “Analog
Bus” in the “Service Key Menus and Error Messages” chapter for additional
information.
--
Phase Lock Diagnostic Tools
error messages
diagnostic routines
Phase Lock Error Messages
All phase lock error messages can result from improper front panel connections.
NO IF FOUND: CHECK R INPUT LEVEL means no IF was detected during pretune:
a source problem. Perform the “A4 Sampler/Mixer Check.”
NO PHASE LOCK: CHECK R INPUT LEVEL means the IF was not acquired after
pretune: a source problem. Perform the “A4 Sampler/Mixer Check,” earlier in
this chapter.
PHASE LOCK CAL FAILED means that a calculation of pretune values was not
successful: a source or receiver failure. Perform the “Source Pretune Correction
Constants” routine as outlined in the “Adjustments and Correction Constants”
chapter. If the analyzer fails that routine, perform the “A4 Sampler/Mixer
Check. ”
PHASE LOCK LOST means that phase lock was lost or interrupted before the band
sweep ended: a source problem. Refer to “Phase Lock Diagnostic Routines”
next to access the phase lock loop diagnostic service routine. Then troubleshoot
the problem by following the procedures in this chapter.
Source Troubleshooting
7-39
Phase Lock Diagnostic Routines
Perform the following steps to determine at what frequencies and bands the
phase lock problem occurs.
1. Press [PRESET] [SYSTEM] [SERVICE MENU] [SERVICE MODES] [PLL AUTO OFF] to
switch off the automatic phase-locked loop. Normally, when the phase-locked
loop detects lock problems, it automatically aborts the sweep and attempts to
recalibrate the pretune cycle. Switching off PLL AUTO defeats this routine.
2. Press [PLL DIAG ON] to switch on the phase-locked loop diagnostic service
mode. In this mode, the phase lock cycle and subsweep number are displayed
on the analyzer display. (See “Service modes menu” in the “Service Key
Menus and Error Messages” chapter for more information.)
3. Press [PLL PAUSE] to pause the phase lock sequence and determine where the
source is trying to tune when lock is lost.
Refer to “Source theory” in the “Theory of Operation” chapter for additional
information regarding band related problems. Then use the procedures in this
chapter to check source functions at specific frequencies.
Broadband Power Problems
This section assumes that a power problem exists across the full frequency
range, but that no error message is displayed on the analyzer. The problem will
only effect the reflection test port. Assemblies in question include:
-
A3 source
n
A30 dual directional coupler
n
any cables from the A3 source to the output of the reflection test port
7-40
Source Troubleshooting
8
Receiver Troubleshooting
Use this procedure only if you have read the “Start Troubleshooting Here”
chapter. Follow the procedures in the order given, unless instructed otherwise.
-
The receiver group assemblies consist of the following:
A4/5/6 sampler/mixer assemblies
n
A10 digital IF assembly
n
A30 dual directional coupler
Receiver Troubleshooting
9-1
Assembly Replacement Sequence
The following steps show the sequence to replace an assembly in an HP 8752C
Network Analyzer.
1. Identify the faulty group. Refer to the “Start Troubleshooting Here” chapter.
Follow up with the appropriate troubleshooting chapter that identifies the
faulty assembly.
2. Order a replacement assembly. Refer to the “Replaceable Parts” chapter.
3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to the “Assembly Replacement and Post-Repair Procedures” chapter.
4. Perform the necessary adjustments. Refer to the “Adjustments and
Correction Constants” chapter.
5. Perform the necessary performance tests. Refer to the “System Verification
and Performance Tests” chapter.
Receiver Failure Error Messages
There are two error messages that indicate receiver group problems. These
messages may be caused by the analyzer itself or by external devices or
connections. An explanation of each error message follows.
CAUTION: OVERLOAD ON REFL PORT, POWER REDUCED
You have exceeded approximately + 20 dBm at the reflection port. The RF
output power is automatically reduced to –20 dBm. The annotation P
appears in the left margin of the display to indicate that the power trip function
has been activated.
To reset the analyzer’s power and regain control of the power level, do the
following:
1. Remove any devices under test which may have contributed excess power to
the analyzer’s reflection port.
2. Press [MENU] [POWER] [0] [x1] [SOURCE POWER ON] to turn the analyzer’s
internal source back on.
8-2
Receiver Troubleshooting
q
q
If the power trip indicator
does not reappear, reconfigure the test
setup to keep input power levels at 0 dBm or below.
If
reappears, continue with “Check the R, A, and B Inputs.”
CAUTION: OVERLOAD ON TRANS PORT, POWER REDUCED
You have exceeded approximately +4 dBm at the transmission port. The
RF output power is automatically reduced to –20 dBm. The annotation P
appears in the left margin of the display to indicate that the power trip function
has been activated.
To reset the analyzer’s power and regain control of the power level, do the
following:
1. Remove any devices under test which may have contributed excess power to
the analyzer’s transmission port.
2. Connect a cable from the reflection port to the transmission port.
3. Press [MENU] [POWER] [0] [x1] [SOURCE POWER ON] to turn the analyzer’s
internal source back on.
q
q
If the power trip indicator
does not reappear, reconfigure the test
setup to keep input power levels at 0 dBm or below.
If
reappears, continue with “Check the R, A, and B Inputs.”
Receiver Troubleshooting
9-3
Check the R, A, and B Inputs
Use the following procedure to check the flatness of the R, A, and B input
traces by comparing them with the sample traces shown in Figure 8-1 through
Figure 8-3.
1. Check the R trace
a. Press [MEAS] [INPUT PORTS] [R] [SCALE REF] [AUTO SCALE].
b. Check the flatness of the R trace by comparing it with the trace in
Figure 8-1.
Figure 8-1. Sample R Input Trace
2. Check the A trace.
a. Connect a short to the reflection test port of the analyzer.
b. Press [MEAS] [INPUT PORTS][A][SCALE REF] [AUTO SCALE].
c. Check the flatness of the input A trace by comparing it with the trace in
Figure 8-2.
8-4
Receiver Troubleshooting
sh6104C
Figure 8-2. Sample A Input Trace
3. Check the B trace.
a. Connect a thru cable from the reflection test port to the transmission test
port of the analyzer.
b. Press [MEAS] [INPUT PORTS][B][SCALE REF] [AUTO SCALE].
c. Check the flatness of the input B trace by comparing it with the trace in
Figure 8-3.
Receiver Troubleshooting
9-5
Figure 8-3. Sample B Input Trace
4. Review the results.
8-6
q
If none of the input traces resemble the corresponding sample trace,
continue with “Troubleshooting When All Inp;uts Look Bad.”
q
If at least one input trace resembles its corresponding sample trace,
continue with “Troubleshooting When One or More Inputs Look Good.”
Receiver Troubleshooting
Troubleshooting When All Inputs Look Bad
Run Internal Tests 18 and 17
1. Press [PRESET] [SYSTEM] [SERVICE MENU] [TESTS] [18] [x1] [EXECUTE TEST] to
run the ADC offset.
2. Then, when the analyzer finishes test 18, press [17] [x1] [EXECUTE TEST] to
run the ADC linearity test.
3. If either of these tests FAIL, continue with “Check the 4 MHz REF Signal.”
Receiver Troubleshooting
8-7
Check the 4 MHz REF Signal
1. Press [PRESET].
2. Use an oscilloscope to observe the 4 MHz reference signal at A10P2-6.
If the signal does not resemble Figure 8-4, troubleshoot the signal source
(A12P2-36) and path.
If the signal is good, the probability is greater than 90% that the A10
assembly is faulty. For confirmation, perform “Vhrvk S10 by Substitution
or Signal Examination..”
0.00000
-500.000 nsec
sec
Ch. 1 = 1.000 volts/div
Timebase = 100 nsec/div
500.000 nsec
Offset =0.000 volts
Delay = 0.00000 sec
sg603s
Figure 8-4. 4 MHz REF Waveform
Check A10 by Substitution or Signal Examination
If the 4 MHz REF signal is good at the A10 digital IF assembly, check the A10
assembly by one of the following methods:
Substitute another A10 assembly and rerun internal tests 18 and 17.
n
n
Check the signal/control lines required for its operation. The pins and signal
sources of those lines are identified in Table 8-1. It is possible that the A9
assembly may not be providing the necessary signals. These signal checks
allow you to determine which assembly is faulty. Some of the waveforms are
illustrated by Figure 8-5 and Figure 8-6.
8-8
Receiver Troubleshooting
If the substitute assembly shows no improvement or if all of the input signals
are valid, continue with “Check the 4 kHz Signal.” Otherwise troubleshoot the
suspect signal(s) or consider the A10 assembly faulty.
Table 8-1. Signals Required for A10 Assembly Operation
Mnemonic
Description
A10
Location
Signal
Source
See
Figure
DIFDO
Digital IF data 0 (LSB)
P2-27
A9P2-27
*
DIFD1
Digital IF data 1
P2-57
A9P2-57
*
DIGD2
Digital IF data 2
P2-28
A9P2-28
*
DIFD3
Digital IF data 3
P2-58
A9P2-58
*
DIFD4
Digital IF data 4
P2-29
A9P2-29
*
DIFD5
Digital IF data 5
P2-59
A9P2-59
*
DIFD6
Digital IF data 6
P2-30
A9P2-30
*
DIFD7
Digital IF data 7 (MSB)
P2-60
A9P2-60
*
L DIFENO
Digital IF enable 0
P2-34
A9P2-34
*
L DIFEN1
Digital IF enable 1
P2-5
A9P2-5
*
L DIFEN2
Digital IF enable 2
P2-35
A9P2-35
*
DIFCC
Digital IF conversion comp.
P2-33
A10P2-33
Figure 8-6
DIFCLK
Digital IF serial clock
P2-4
A10P2-4
Figure 8-5
DIF DATA
Digital IF serial data out
P2-3
A10P2-3
Figure 8-5
L ENDIF
L-enable digital IF
P2-17
A9P2-17
Figure 8-6
L INTCOP
L-interrupt, DSP
P2-2
A10P2-2
Figure 8-6
* Check for TTL activity.
Receiver Troubleshooting
8-9
DIFCLK
DIF DATA*
* DIF DATA consists of 16 serial bits per input conversion.
the LSB is on the right side and is the most volatile.
Figure 8-5. Digital Data Lines Observed Using L INTCOP as Trigger
= 20.0 us/div
sg604s
Figure 8-6. Digital Control Lines Observed Using L INTCOP as Trigger
9-10
Receiver Troubleshooting
Troubleshooting When One or More Inputs Look Good
Since at least one input is good, all of the common receiver circuitry beyond the
multiplexer is functional. Only the status of the individual sampler/mixers and
their individual signal paths is undetermined.
q
q
If all inputs look good but the average power level is incorrect, continue with
“Check the Frequency Response Correction.”
If one or two inputs look bad, continue with “Check the 4 kHz Signal.”
Check the Frequency Response Correction
1. Remove all connections to the reflection and transmission ports and press
[PRESET] You should observe a straight line at 0 dB with a scale of 5 dB/DIV.
2. Connect a thru between the reflection and transmission ports. Press [CH 2].
The trace observed should be the same as the previous one.
q
q
If the traces are not as described, perform the Frequency Response
Correction adjustment in the “Adjustments and Correction Constants”
chapter.
If the traces are still not as described after performing the adjustment,
replace the A10 assembly.
Check the 4 kHz Signal
1. Press
[PRESET] [MENU]
CW FREQ] .
2. Use an oscilloscope to check the 4 kHz output of the sampler/mixer in
question at the Al0 assembly. The input and output access pins are listed in
Table 8-2. The signal should resemble the waveform of Figure 8-7.
q
If the signal is good, replace the A10 assembly.
q
If the signal is bad, continue with “Check 1st LO Signal at Sampler/Mixer.”
Receiver Troubleshooting
8-11
Table 8-2. 2nd IF (4 kHz) Signal Locations
Mnemonic
Description
A10 Location
Signal Source
IFR
4 kHz
A10P1-1, 31
A4P1-6
IFA
4 kHz
A10P1-4, 34
A5P1-6
IFB
4 kHz
A10P1-7, 37
A6P1-6
-500. 000 usec
0.00000
Ch. 1 = 1.000 volts/div
Timebase = 100 usec/div
Vmarker1 = 20.00 mvolts
sec
Vmarker2 = 20.00
500.000 usec
Offset = 28.00 mvolts
Delay = 0.00000 sec
Delto V = 0.000 volts
sg605s
Figure 8-7. 2nd IF (4 kHz) Waveform
Check 1st LO Signal at Sampler/Mixer
If the 4 kHz signal is bad at the sampler/mixer assembly, check the 1st LO signal
where it enters the sampler/mixer assembly in question.
q
If the 1st LO is faulty, check the 1st LO signal at its output connector on the
A7 assembly to determine if the failure is in the cable or the assembly.
q
If the 1st LO is good, continue with “Check 2nd LO Signal at Sampler/Mixer.”
8-12
Receiver Troubleshooting
Check 2nd LO Signal at Sampler/Mixer
Check the 2nd LO signal at the pins identified in Table 8-3. Refer to the “Al2
Reference Check” in the “Source Troubleshooting” chapter for analog bus
and oscilloscope checks of the 2nd LO and waveform illustrations. Table 8-3
identifies the signal location at the samplers and the Al2 assembly.
Table 8-3. 2nd LO Locations
Mnemonic
Description
Sampler
Location
Signal
Source
2nd LO 1
2nd LO (0 degrees)
A41516 P1-11
A12P1-2, 32
2nd LO 2
2nd LO (-90 degrees)
A4/5/6 P1-4
A12P1-4, 34
• If the 2nd LO is bad, troubleshoot the Al2 reference assembly and signal
path.
• If the 2nd LO is good and the B sampler is suspected faulty, replace the A6
(B) sampler/mixer.
• If the 2nd LO is good but the R or A sampler is suspected faulty, continue
with “Check Input Trace.”
Receiver Troubleshooting
9-13
Check Input Trace
All inputs to the sampler have been verified except for the signal coming from
the coupler. The problem is most likely a faulty coupler or sampler. However,
the A10 assembly may also be at fault.
Press [PRESET] [MEAS] [INPUT PORTS] and select the input with the bad trace.
The trace normally has a number of jumps in it due to band switches, as shown
in Figure 8-l through Figure 8-3. Each jump should be less than 2 dB.
q
q
If there are other peaks or holes in the trace, the sampler is probably faulty.
Remove the suspected sampler and exchange it with the known good sampler.
If the problem disappears, replace the suspected sampler.
If there is a broadband problem, it is probably caused by the coupler.
n
If the level (average value) of the trace is wrong but the trace is otherwise
correct, the problem is most likely in the coupler or the A10 assembly.
Either measure the output of the coupler with a power meter, or swap the
Al0 assembly with another known working A10 assembly.
n
Check directivity, source match, and crosstalk by performing the
system verification procedure described in the “System Verification and
Performance Tests” chapter. If any of these fail, check the coupler and
sampler connections.
To verify the coupler is faulty, remove the sampler that has the bad input
and exchange it with the known good sampler. If there is no improvement,
replace the coupler. If the problem disappears, replace the original sampler.
If the 2nd LO is good at the sampler/mixer, the sampler/mixer assembly is faulty.
Otherwise, troubleshoot the Al2 assembly and associated signal path.
8-14
Receiver Troubleshooting
9
Accessories Troubleshooting
Use this procedure only if you have read Chapter 4, “Start Troubleshooting
Here.” Follow the procedures in the order given, unless instructed otherwise.
Measurement failures can be divided into two categories:
n
Failures which don’t affect the normal functioning of the analyzer but render
incorrect measurement data.
n
Failures which impede the normal functioning of the analyzer or prohibit the
use of a feature.
This chapter addresses the first category of failures which are usually caused by
the following:
--
n
operator errors
n
faulty calibration devices or connectors
n
bad cables or adapters
improper calibration techniques
These failures are checked using the following procedures:
“Inspect the Accessories”
“Inspect the Error Terms”
Accessories Troubleshooting
9-1
Assembly Replacement Sequence
The following steps show the sequence to replace an assembly in an HP 8752C
Network Analyzer.
1. Identify the faulty group. Refer to the “Start Troubleshooting Here” chapter.
Follow up with the appropriate troubleshooting chapter that identifies the
faulty assembly.
2. Order a replacement assembly. Refer to the “Replaceable Parts” chapter.
3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to the “Assembly Replacement and Post-Repair Procedures” chapter.
4. Perform the necessary adjustments. Refer to the “Adjustments and
Correction Constants” chapter.
5. Perform the necessary performance tests. Refer to the “System Verification
and Performance Tests” chapter.
9-2
Accessories Troubleshooting
Inspect the Accessories
Inspect the Test Port Connectors and Calibration Devices
1. Check for damage to the mating contacts of the test port center conductors
and loose connector bulkheads.
2. Inspect the calibration kit devices for bent or broken center conductors and
other physical damage. Refer to the calibration kit operating and service
manual for information on gaging and inspecting the device connectors.
If any calibration device is obviously damaged or out of mechanical
tolerance, replace the device.
Inspect the Error Terms
Error terms are a measure of a “system”: a network analyzer, calibration kit,
and any cables used. As required, refer to Chapter 11, “Error Terms”, for the
following:
n
The specific measurement calibration procedure used to generate the error
terms.
n
The routines required to extract error terms from the instrument.
-
Typical error term data.
Use Table 9-l to cross-reference error term data to system faults.
Accessories Troubleshooting
9-3
Table 9-l. Components Related to Specific Error Terms
X
A10 digital IF
dual directional coupler
X
X
X
X
X
X
test port connectors
X
X
X
X
X
X
X
X
External cables
If you detect problems using error term analysis, use the following approach to
isolate the fault:
1. Check the cable by examining the load match and transmission tracking
terms. If those terms are incorrect, go to “Cable Test”.
2. Verify the calibration kit devices:
Loads: If the directivity error term looks good, the load and the port are
good. If directivity looks bad, check directivity again with a known good
load. If the problem is still present, replace the dual directional coupler
assembly.
Shorts and opens: If the source match and reflection tracking terms look
good, the shorts and the opens are good. If these terms look bad while the
rest of the terms look good, proceed to “Verify Shorts and Opens.”
9-4
Accessories Troubleshooting
Cable Test
The load match error term is a good indicator of cable problems. You can
further verify a faulty cable by measuring the reflection of the cable. Connect
the suspect cable between the reflection port and the transmission port.
Figure 9-1 shows the return loss trace of a good (left side) and faulty cable.
Note that the important characteristic of a cable trace is its level (the good cable
trace is much lower) not its regularity. Refer to the cable manual for return loss
specifications.
Another way to verify the operation of the cable is to run the Cable Confidence
Test (test number 22). Press [SYSTEM] [SERVICE MENU] [TESTS] [22] [x1][ EXECUTE].
sh6114c
Figure 9-1. Typical Return Loss Traces of Good and Poor Cables
Accessories Troubleshooting
9-5
Verify Shorts and Opens
Substitute a known good short and open of the same connector type and sex as
the short and open in question. If the devices are not from one of the standard
calibration kits, refer to the HP 8752C Network Analyzer User’s Guide for
information on how to use the [MODIFY CAL KIT] function. Set aside the short
and open that are causing the problem.
1. Perform a reflection l-port calibration using the good short and open. Then
press [FORMAT] [SMITH CHART] to view the devices in Smith chart format.
2. Connect the good short to the reflection port. Press [SCALE REF]
[ELECTRICAL DELAY]. Turn the front panel knob to enter enough electrical
delay so that the trace appears as a dot at the left side of the smith chart
(see Figure 9-2a).
Replace the good short with the questionable short at the reflection port.
The trace of the questionable short should appear very similar to the known
good short.
3. Connect the good open to the reflection port. Press [SCALE REF]
[ELECTRICAL DELAY] and turn the front panel knob to enter enough electrical
delay so that the trace appears as a dot at the right side of the circle (see
Figure 9-2b).
Replace the good open with the questionable open at the reflection port. The
trace of the questionable open should appear very similar to the known good
open.
9-6
Accessories Troubleshooting
(B)
sh6115c
Figure 9-2. Typical Smith ChartTraces of Good Short (a) and Open (b)
Accessories Troubleshooting
9-7
Error Terms
The analyzer generates and stores factors in internal arrays when a
measurement error-correction (measurement calibration) is performed. These
factors are known by the following terms:
-
n
n
error terms
E-terms
measurement calibration coefficients
The analyzer creates error terms by measuring well-defined calibration devices
over the frequency range of interest and comparing the measured data with the
ideal model for the devices. The differences represent systematic (repeatable)
errors of the analyzer system. The resulting calibration coefficients are good
representations of the systematic error sources. For details on the various levels
of error-correction, refer to the “Optimizing Measurement Results” chapter of
the HP 8752C Network Analyzer User’s Guide . For details on the theory of
error-correction, refer to the “Application and Operation Concepts” chapter of
the HP 8752C Network Analyzer User’s Guide.
Error Terms
11-1
Error Terms Can Also Serve a Diagnostic Purpose
Specific parts of the analyzer and its accessories directly contribute to the
characteristics of the error terms. Since we know this correlation and we know
what typical error terms look like, we can examine error terms to monitor
system performance (preventive maintenance) or to identify faulty components
in the system (troubleshooting).
Preventive Maintenance: A stable, repeatable system should generate
repeatable error terms over long time intervals, for example, six months.
If you make a hardcopy record (print or plot) of the error terms, you can
periodically compare current error terms with the record. A sudden shift in
the values of the error terms reflects a sudden shift in systematic errors, and
may indicate the need for further troubleshooting. A long-term trend often
reflects drift, connector and cable wear, or gradual degradation, indicating the
need for further investigation and preventive maintenance. Yet, the system
may still conform to specifications. The cure is often as simple as cleaning and
gaging connectors or inspecting cables.
Troubleshooting: If a subtle failure or mild performance problem is
suspected, the magnitude of the error terms should be compared against
values generated previously with the same instrument and calibration kit.
This comparison will produce the most precise view of the problem.
However, if previously generated values are not available, compare the
current values to the typical values listed in Table 11-2, and shown graphically
on the plots in this chapter. If the magnitude exceeds its limit, inspect the
corresponding system component, which may ultimately need replacing.
Consider the following while troubleshooting:
All parts of the system, including cables and calibration devices, can
contribute to systematic errors and impact the error terms.
Connectors must be clean, gaged, and within specification for error term
analysis to be meaningful.
Avoid unnecessary bending and flexing of the cables following measurement
calibration, minimizing cable instability errors.
Use good connection techniques during the measurement calibration.
The connector interface must be repeatable. Refer to the “Principles
of Microwave Connector Care” section in the “Service Equipment and
Analyzer Options” chapter for information on connection techniques and on
cleaning and gaging connectors.
11-2
Error Terms
q
Use error term analysis to troubleshoot minor, subtle performance problems.
Refer to the “Start Troubleshooting Here” chapter if a blatant failure or
gross measurement error is evident.
q
It is often worthwhile to perform the procedure twice (using two distinct
measurement calibrations) to establish the degree of repeatability. If the
results do not seem repeatable, check all connectors and cables.
Error Terms
11-3
Reflection 1-Port Error-Correction Procedure
1. Set any measurement parameters that you want for the device
measurement: power, format, number of points, IF bandwidth.
2. To access the measurement correction menus, press:
[CAL]
3. Assuming that your calibration kit is the N 503 default, press:
[CAL KIT] [N 50 ohm] [RETURN]
4. To select the correction type, press:
[CALIBRATE MENU] [REFLECTION 1-PORT]
5. Connect a shielded open circuit to the REFLECTION port. See Figure 11-1.
HP 8752C
OPEN
SHORT
LOAD
* DIRECT CONNECTION
Figure 11-l. Standard Connections for One-Port Error-Correction
11-4
Error Terms
6. To measure the standard, press:
[FORWARD: OPENS] [OPEN (f)]
When the analyzer is done measuring the standard, press:
[DONE: OPENS]
7. Disconnect the open, and connect a short circuit to the REFLECTION port.
8. To measure the device, press:
[FORWARD: SHORTS] [SHORT (f)]
After the beep, press:
[DONE: SHORTS]
9. Disconnect the short, and connect an impedance-matched load to the
REFLECTION port.
10. To measure the standard, press:
[FORWARD : LOAD]
The analyzer underlines the [LOAD] softkey after it measures the standard.
11. To compute the reflection correction coefficients, press:
[DONE: 1-PORT GAL]
Error Terms
11-5
Response and Isolation Calibration Procedures
1. Press [MEAS] [TRANSMISSN].
2. Press [CAL] [CAL KIT] [N 50 ohm] [RETURN].
3. Press [CALIBRATE MENU] [RESPONSE & ISOL 'N].
4. Press [RESPONSE].
5. Connect equipment as shown in Figure 11-2.
U
24 INCH
TYPE-N
RF CABLE
Figure 11-2. Standard Connections for Response Calibration
6. Press [THRU].
7. After the beep, press [DONE: RESPONSE].
8. Connect the equipment as shown in Figure 11-3.
11-6
Error Terms
HP 8752C
RF CABLE
*
DIRECT CONNECTION
Figure 11-3. Standard Connections for Isolation Calibration
9. Press [ISOL'N STD].
10. After the beep, press [DONE: RESP ISOL'N CAL].
11. This completes the full two-port correction procedure. You can connect and
measure your device under test.
Table 11-l. Calibration Coefficient Terms and Tests
Calibration
Coefficient
1
2
3
Calibration Type
1-port
Test
Number
Response
Response
and Isolation 1
ER or ET
EX (ED)
ED
32
ET (ER)
ES
33
ER
34
NOTES:
Meaning of first subscript: D-directivity; S-source match; R-reflection tracking; X-crosstalk;
L=load match; T=transmission tracking.
1 Response and Isolation cal yields: EX or ET if a transmission measurement or ED or ER if a
reflection measurement.
Error Terms
11-7
Error Term Inspection
Note
If the correction is not active, press [CAL] [CORRECTION ON].
1. Press [SYSTEM] [SERVICE MENU] [TESTS] [32] [x1] [EXECUTE TEST].
The analyzer copies the first calibration measurement trace for the selected
error term into memory and then displays it. Table 11-2 lists the test
numbers.
2. Press [SCALE REF] and adjust the scale and reference to study the error term
trace.
3. Press [MKR FCTN] and use the marker functions to determine the error term
magnitude.
4. Compare the displayed measurement trace to the trace shown in the
following “Error Term descriptions” section, and to previously measured
data. If data is not available from previous measurements, refer to the
typical uncorrected performance specifications listed in Table 11-2.
5. Make a hardcopy of the measurement results:
a. Connect a printing or plotting peripheral to the analyzer.
b. Press [LOCAL] [SYSTEM CONTROLLER] [SET ADDRESSES] and select the
appropriate peripheral to verify that the HP-IB address is set correctly on
the analyzer.
c. Press [SAVE/RECALL] and then choose either [PRINT] or [PLOT].
d. Press [DISPLAY] [MORE] [TITLE] and title each data trace so that you can
identify it later.
for detailed information on creating hardcopies, refer to “Printing,
Plotting, and Saving Measurement Results” in the HP 8752C Network
Analzyer User’s Guide.
11-8
Error Terms
If Error Terms Seem Worse than Typical Values
1. Perform a system verification to verify that the system still conforms to
specifications.
2. If system verification fails, refer to “Start Troubleshooting Here.”
Uncorrected Performance
The following table shows typical performance without error-correction. RF
cables are not used except as noted. Related error terms should be within these
values.
Table 11-2. Uncorrected System Performance
Frequency Range (GHz)
0.0003 to1.3
1.3 to 3.0
3.0 to 6.0
Directivity
40 dB1
36 dB
Source Match
30 dB
26 dB
20 dB
Reflection Tracking
±0.2 dB
±0.3 dB
±0.4 dB
Transmission Tracking
±0.2 dB
±0.3 dB
±0.4 dB
100 dB
100 dB
90 dB
Crosstalk
32 dB
1 30 dB, 300 kHzzto10 MHz
Error Terms
11-9
Error Term Descriptions
The error term descriptions in this section include the following information:
-
n
n
significance of each error term
typical results following either a reflection l-port or a response and isolation
calibration
guidelines to interpret each error term
11-10
Error Terms
Directivity (ED) - After a Reflection 1-Port Calibration
Description
Directivity is a measure of any detected power that is reflected when a load is
attached to the test port. The directivity error of the test port is determined by
measuring the reflection of the load during the error-correction procedure.
-
Significant System Components
n
load used in the error-correction (calibration)
test port connectors
analyzer’s directional coupler
Affected Measurements
Low reflection device measurements are most affected by directivity errors,
Highly reflective device measurements will look normal.
Procedure
To view the analyzer’s directivity parameters, perform a 1-port calibration, then
press: [SYSTEM] [SERVICE MENU] [TEST] [32] [x1].
Error Terms
11-11
Figure 11-4. Typical ED (Reflection Test Port)
11-12
Error Terms
Source Match (ES) - After a Reflection 1-Port Calibration
Description
Source match is a measure of test port connector match, as well as the match
between all components from the source to the test port. It is obtained by
measuring the reflection of an open and a short connected directly to the test
port.
Significant System Components
-
n
n
n
open calibration kit device
short calibration kit device
analyzer’s directional coupler
test port connectors
Affected Measurements
Reflection and transmission measurements of highly reflective devices are most
affected by source match errors.
Procedure
To view the analyzer’s source match parameters, perform a 1-port calibration,
then press: [SYSTEM] [SERVICE MENU] [TEST] [33] [x1].
Error Terms
11-13
sh6125c
Figure 11-5. Typical ES (Reflection Test Port)
11-14
Error Terms
Reflection Tracking (ER) . After a Reflection 1-Port Calibration
Description
Reflection tracking is the difference between the frequency response of the
reference path (R path) and the frequency response of the reflection test path
(A input path). The error term is obtained by measuring the reflections of an
open and a short during calibration.
Significant System Components
n
n
n
open calibration kit device
short calibration kit device
R or A signal path for large variation in ER
Affected Measurements
All reflection measurements (high or low return loss) are affected by the
reflection tracking errors.
Procedure
To view the analyzer’s reflection tracking parameters, perform a 1-port
calibration, then press: [SYSTEM] [SERVICE MENU] [TEST] [34] [x1].
Error Terms
11-15
Figure 11-6. Typical ER (Reflection Test Port)
11-16
Error Terms
Isolation (Crosstalk, EX) - After a Response and Isolation
(Transmission) Calibration
Description
Isolation is a measure of the leakage between the test ports and the signal
paths. The isolation error terms are characterized by measuring transmission
with loads attached to both ports during the error-correction procedure. Since
these terms are low in magnitude, they are usually noisy (not very repeatable).
The error term magnitude changes dramatically with IF bandwidth: a 10 Hz IF
bandwidth must be used in order to lower the noise floor beyond the crosstalk
specification. Using averaging will also reduce the peak-to-peak noise in this
error term.
Significant System Components
n
sampler crosstalks
Affected Measurements
Transmission measurements, (primarily where the measured signal level is very
low), are affected by isolation errors. For example, transmission measurements
where the insertion loss of the device under test is large.
Procedure
To view the analyzer’s isolation parameters, perform a response and isolation
calibration, then press: [SYSTEM] [SERVICE MENU] [TEST] [34] [x1].
Error Terms
11-17
PRm
Cor
HI d
sh6127c
Figure 11-7. Typical EX with 10 Hz Bandwidth
sh6128c
Figure 11-8. Typical EX with 3 kHz Bandwidth
11-18
Error Terms
Transmission Tracking (ET)
Description
Transmission tracking is the difference between the frequency response of the
reference path (including R input) and the transmission test path (including A
input) while measuring transmission. The response of the test port cables is
included. These terms are characterized by measuring the transmission of the
“thru” configuration during the error-correction procedure.
Significant System Components
n
n
n
R signal path
A input paths
“thru” cable
Affected Measurements
All transmission measurements are affected by transmission tracking errors.
Procedure
To view the analyzer’s transmission tracking parameters, perform a 1-port
calibration, then press: [SYSTEM] [SERVICE MENU] [TEST] [34] [x1].
Error Terms
11-19
sh6129c
Figure 11-9. Typical ET
11-20
Error Terms
12
Theory of Operation
This chapter is divided into two major sections:
n “How the HP 8752C Works” gives a general description of the HP 8752C
network analyzer’s operation.
n
“A Close Look at the Analyzer’s Functional Groups” provides more detailed
operating theory for each of the analyzer’s functional groups.
Theory of Operation
12-1
How the HP 87520 Works
Network analyzers measure the reflection and transmission characteristics of
devices and networks. A network analyzer test system consists of the following:
n
source
n
signal-separation devices
n
receiver
n
display
The analyzer applies a signal that is either transmitted through the device under
test or reflected from its input, and then compares it with the incident signal
generated by the swept RF source. These signals are then applied to a receiver
for measurement, signal processing, and display.
The HP 8752C vector network analyzer integrates a high resolution synthesized
RF source, transmission/reflection test set, and a dual channel three-input
receiver to measure and display magnitude, phase, and group delay of
transmitted and reflected power. The HP 8752C Option 010 has the additional
capability of transforming measured data from frequency domain to time
domain. Figure 12-1 is a simplified block diagram of the network analyzer
system. A detailed block diagram of the analyzer is located at the end of the
“Start Troubleshooting Here” chapter.
.3 GHz
SYNTHESIZED
SOURCE
[ATTEN]
*
30 kHz to 3 or 6 GHz R
TEST
SET
A
RECEIVER
B
Figure 12-1. Simplified Block Diagram of the Network Analyzer System
12-2
Theory of Operation
The Built-In Synthesized Source
The analyzer’s built-in synthesized source produces a swept RF signal in the
range of 300 kHz to 1.3 GHz. The HP 8752C Option 003 is able to generate
signals up to 3 GHz and the Option 006 generates signals up to 6 GHz. The
source output power is leveled by an internal ALC (automatic leveling control)
circuit. To achieve frequency accuracy and phase measuring capability, the
analyzer is phase locked to a highly stable crystal oscillator.
For this purpose, a portion of the transmitted signal is routed to the R
sampler/mixer of the receiver, where it is sampled by the phase detection loop
and fed back to the source.
The Source Step Attenuator (Option 004)
The HP 8752C Option 004 includes a 70 dB, electro-mechanical step attenuator.
This very low-loss attenuator is contained in the source assembly. It is used to
adjust the power level to the device under test without changing the level of
the incident power in the reference path. The user sets the attenuation levels
via the front panel softkeys.
Theory of Operation
12-3
The Built-In Transmission/Reflection Test Set
The HP 8752C features a built-in test set that provides the signal separation
capability for the device under test. The test uses a dual directional coupler
to separate the incident signal from the transmitted and reflected signals. The
incident signal is applied to the R sampler/mixer via one of coupled arms of the
dual directional coupler. Meanwhile, the reflected signal is routed from the
reflection test port via the other coupled arm of the dual directional coupler
to the input of the A sampler/mixer in the receiver. The transmitted signal is
fed directly from the transmission test port to the B sampler/mixer. (Analyzers
having Option 006 have an 8 dB pad between the transmission test port and the
B sampler/mixer.)
The Receiver Block
The receiver block contains three sampler/mixers (for the R, A, and B
inputs). The signals are sampled and down-converted to produce a 4 kHz IF
(intermediate frequency). A multiplexer sequentially directs each of the three
IF signals to the ADC (analog to digital converter) where it is converted from
an analog to a digital signal to be measured and processed for viewing on the
display. Both amplitude and phase information are measured simultaneously,
regardless of what is displayed on the analyzer.
The Microprocessor
A microprocessor takes the raw data and performs all the required error
correction, trace math, formatting, scaling, averaging, and marker operations
according to the instructions from the front panel or over HP-IB. The formatted
data is then displayed.
12-4
Theory of Operation
A Close Look at the Analyzer’s Functional Groups
The operation of the analyzer can be divided into five functional groups. Each
group consists of several major assemblies and performs a distinct function.
Some assemblies are related to more than one group, and in fact all the groups
are to some extent interrelated and affect each other’s performance.
Power Supply. The power supply functional group consists of the A8 post
regulator and the Al5 preregulator. It supplies power to the other assemblies
in the instrument.
Digital Control. The digital control group consists of the Al front panel and
A2 front panel processor, the A9 CPU, the Al6 rear panel, the Al8 display,
and the A19 graphics system processor (GSP) assemblies. The A10 digital IF
assembly is also related to this group. These assemblies combine to provide
digital control for the analyzer.
Source. The source group consists of the A3 source, A7 pulse
phase lock, Al2 reference, Al3 fractional-N (analog), and Al4
(digital) assemblies. The A4 R sampler is also related since it is
source phase lock loop. The source supplies a phase-locked RF
device under test.
generator, All
fractional-N
part of the
signal to the
Signal Separation. The signal separation group consists of the A30 dual
directional coupler assembly. This assembly performs the function of a
reflection/transmission test set. It divides the source signal into a reference
path and a test path, and provides connections to the device under test.
Receiver. The receiver group consists of the A4/A5/A6 sampler/mixers and
the A10 digital IF assemblies. The Al2 reference assembly and the A9 CPU
assembly are also related. The receiver measures and processes input signals
for display.
The following pages describe the operation of each of the functional groups.
Theory of Operation
12-5
Power Supply Theory
The power supply functional group consists of the Al5 preregulator and the
A8 post regulator. These two assemblies comprise a switching power supply
that provides regulated DC voltages to power all assemblies in the analyzer. The
Al5 preregulator is enclosed in a casting at the rear of the instrument behind
the display. It is connected to the A8 post regulator by a wire bus (A15W1).
Figure 12-2 is a simplified block diagram of the power supply group.
OFF DURING
N O R M A L OPTERATION
ALL ON DURING
N O R M A L OPERATION
ON DURING
NORMAL OPERATION
sg636d
Figure 12-2. Power Supply Functional Group, Simplified Block Diagram
A15 Preregulator
The A15 preregulator steps down and rectifies the line voltage. It provides a
fully regulated +5V digital supply, and several preregulated voltages that go to
the A8 post regulator assembly for additional regulation.
The A15 preregulator assembly includes the line power module, a 60 kHz
switching preregulator, and overvoltage protection for the + 5V digital supply. It
provides LEDs (visible from the rear of the instrument) to indicate either normal
operating or shutdown status.
12-6
Theory of Operation
Line Power Module
The line power module includes the line power switch, voltage selector switch,
and main fuse. The line power switch is activated from the front panel. The
voltage selector switch, accessible at the rear panel, adapts the analyzer to local
line voltages of approximately 115V or 230V (with 350 VA maximum). The main
fuse, which protects the input side of the preregulator against drawing excessive
line current, is also accessible at the rear panel. Refer to the HP 8752C Network
Analyzer Installation and Quick Start Guide for line voltage tolerances and
other power considerations.
Preregulated Voltages
The switching preregulator converts the line voltage to several DC voltages.
The regulated +5V digital supply is routed directly to the motherboard. The
following partially regulated voltages are routed through A15W1 to the A8 post
regulator for final regulation:
+70V +25V +18V -18V +8V -8V
Regulated + 5V Digital Supply
The + 5VD supply is regulated by the control circuitry in the Al5 preregulator.
It is routed directly to the motherboard, and from there to all assemblies
requiring a low noise digital supply. A +5V sense line returns from the
motherboard to the Al5 preregulator. The + 5V CPU is derived from the + 5 VD
in the A8 post regulator and goes directly to the A19 GSP.
In order for the preregulator to function, the +5V digital supply must be loaded
by one or more assemblies, and the +5V sense line must be working. If not, the
other preregulated voltages will not be correct.
Shutdown Indications: the Green LED and Red LED
The green LED is on in normal operation. It is off when line power is not
connected, not switched on, set too low, or if the line fuse has blown.
The red LED, which is off in normal operation, lights to indicate a fault in the
+5V supply. This may be an over/under line voltage, over line current, or
overtemperature condition. Refer to the troubleshooting chapters for more
information.
Theory of Operation
12-7
A8 Post Regulator
The A8 post regulator filters and regulates the DC voltages received from the
Al5 preregulator. It provides fusing and shutdown circuitry for individual
voltage supplies. It distributes regulated constant voltages to the individual
assemblies throughout the instrument. It includes the overtemperature
shutdown circuit, the variable fan speed circuit, and the air flow detector. Nine
green LEDs provide status indications for the individual voltage supplies.
Refer to the “Power Supply Block Diagram” located at the end of the “Power
Supply Troubleshooting” chapter to see the voltages provided by the A8 post
regulator.
Voltage Indications: the Green LEDs
The nine green LEDs along the top edge of the A8 assembly are on in normal
operation, to indicate the correct voltage is present in each supply. If they are
off or flashing, a problem is indicated. The troubleshooting procedures later in
this chapter detail the steps to trace the cause of the problem.
Shutdown Circuit
The shutdown circuit is triggered by overcurrent, overvoltage, undervoltage, or
overtemperature. It protects the instrument by causing the regulated voltage
supplies to be shut down. It also sends status messages to the A9 CPU to trigger
warning messages on the analyzer’s display. The voltages that are not shut
down are the + 5VD and + 5VCPU digital supplies from the preregulator, the
fan supplies, the probe power supplies, and the display supplies. The shutdown
circuit can be disabled momentarily for troubleshooting purposes by jumpering
the SDIS line (A8TP4) to ground.
Variable Fan Circuit and Air Flow Detector
The fan power is derived directly from the +18V and -18V supplies from the
Al5 preregulator. Because the fan is not fused, it will continue to provide
airflow and cooling when the instrument is otherwise disabled. If overheating
occurs, the main instrument supplies are shut down and the fan runs at full
speed. An overtemperature status message is sent to the A9 CPU to initiate a
warning message on the analyzer’s display. The fan also runs at full speed if the
air flow detector senses a low output of air from the fan. (Full speed is normal
at initial power on.)
12-8
Theory of Operation
Display Power
The A8 assembly supplies voltages to the display through a wire cable. The A8
supplies + 5VCPU and + 65V to the A19 GSP, then the + 65V is routed to the
display. Because they are not connected to the protective shutdown circuitry,
the A18 display assemblies can operate during troubleshooting when other
supplies do not work.
Probe Power
The +18V and -18V supplies are post regulated to +15V and -12.6V to provide
a power source at the front panel for an external RF probe or milli-meter
modules.
Digital Control Theory
-
The digital control functional group consists of the following assemblies:
n
A1 front panel
A2 front panel processor
n
A9 CPU
n
A10 digital IF
n
Al6 rear panel
n
A18 display
A19 GSP
These assemblies combine to provide digital control for the entire analyzer.
They provide math processing functions, as well as communications between the
analyzer and an external controller and/or peripherals. Figure 12-3 is a block
diagram of the digital control functional group.
Theory of Operation
12-9
IF B 4 kHz
Figure 12-3. Digital Control Group, Block Diagram
Al Front Panel Keyboard
The A1 front panel keyboard assembly provides user interface with the
analyzer. It includes the keyboard for local user inputs, and the front panel
LEDs that indicate instrument status. The RPG (rotary pulse generator) is not
electrically connected to the Al front panel keyboard, but provides user inputs
directly to the front panel processor.
12-10
Theory of Operation
A2 Front Panel Processor
The A2 front panel processor detects and decodes user inputs from the front
panel keys and RPG knob, and transmits them to the CPU. It has the capability
to interrupt the CPU to provide information updates. It also controls the front
panel LEDs that provide status information to the user.
A9 CPU/A10 Digital IF
The A9 CPU assembly contains the main CPU (central processing unit), the
digital signal processor, memory storage. The main CPU is the master controller
for the analyzer, including the other dedicated microprocessors. The memory
includes EEPROM, RAM, EPROM, and ROM.
Data from the receiver is serially clocked into the A9 CPU assembly from
the A10 digital IF. The data-taking sequence is triggered either from the A14
fractional-N assembly, externally from the rear panel, or by firmware on the A9
assembly.
Main CPU
The main CPU is a 16-bit microprocessor that maintains digital control over the
entire instrument through the instrument bus. The main CPU receives external
control information from the front panel or HP-IB, and performs processing
and formatting operations on the raw data in the main RAM. It controls the
digital signal processor, the front panel processor, the display processor, and
the interconnect port interfaces. In addition, when the analyzer is in the
system controller mode, the main CPU controls peripheral devices through the
peripheral port interfaces.
The main CPU has a dedicated EPROM that contains the operating system
for instrument control. Front panel settings are stored in CMOS RAM, with a
battery providing at least 5 years of backup storage when external power is
switched off.
Main RAM
The main RAM (random access memory) is shared memory for the CPU and
the digital signal processor. It stores the raw data received from the digital
signal processor, while additional calculations are performed on it by the CPU.
The CPU reads the resulting formatted data from the main RAM and converts
it to GSP commands. It writes these commands to the GSP for output to the
analyzer’s display.
Theory of Operation
12-11
Detailed information on the data processing sequence is provided in HP 8752C
Network Analyzer User’s Guide.
EEPROM
EEPROM (electrically-erasable programmable read only memory) contains
factory set correction constants unique to each instrument. These constants
correct for hardware variations to maintain the highest measurement accuracy.
The correction constants can be updated by executing the routines in the
“Adjustments and Correction Constants” chapter.
Digital Signal Processor
The digital signal processor receives the digitized data from the A10 digital
IF. It computes discrete Fourier transforms to extract the complex phase and
magnitude data from the 4 kHz IF signal. The resulting raw data is written into
the main RAM.
Al8 Display
The A18 display is a 7.5-inch raster scan CRT with associated drive circuitry.
It receives a +65V power supply from the A19 GSP, along with digital TTL
horizontal and vertical sync signals, as well as red, green, and blue (RGB)
video signals. Automatic degaussing is performed whenever the instrument is
switched on to minimize the magnetization of the display.
A19 GSP
The A19 graphics system processor (GSP) provides an interface between the
A9 CPU and the Al8 display. The CPU (A9) converts the formatted data to
GSP commands and writes it to the GSP. The GSP processes the data to obtain
the necessary video signals and sends the signals to the A18 display. It also
produces RGB output signals which are sent to the rear panel. The assembly
receives two power supply voltages: +5VCPU, which is used for processing, and
+65V, which is passed on to A18 display but not used on A19 GSP.
12-12
Theory of Operation
Al6 Rear Panel
The Al6 rear panel includes the following interfaces:
TEST SET I/O INTERCONNECT. The HP 8752C cannot be used with external
test sets. However, with an adapter, you can use signal levels for sequencing.
Refer to the “Application and Operation Concepts” chapter of the HP 8752C
Network Analyzer User’s Guide for information on applying the test set
interconnect.
EXT REF IN. This allows for a frequency reference signal input that can
phase lock the analyzer to an external frequency standard for increased
frequency accuracy.
The analyzer automatically enables the external frequency reference feature
when a signal is connected to this input. When the signal is removed, the
analyzer automatically switches back to its internal frequency reference.
AUX INPUT. This allows for a dc or ac voltage input from an external signal
source, such as a detector or function generator, which you can then measure.
(You can also use this connector as an analog output in service routines.)
EXT AM. This allows an external analog signal input to be applied to the
ALC circuitry of the analyzer’s source. This input analog signal amplitude
modulates the RF output signal.
EXT TRIGGER. This allows connection of an external negative
TTL-compatible signal that will trigger a measurement sweep. The trigger can
be set to external through softkey functions.
EXT MON: RED, GREEN, BLUE. Although these interfaces are not
electrically connected to the Al6 rear panel interface board, they are
connected to the rear panel assembly. Three video output connectors
provide analog blue, green, and red video signals which you can use to
drive an analog multi-sync monitor. The monitor must be compatible with
the analyzer’s 25.5 kHz scan rate and video levels: 1 Vp-p, 0.7 V= white,
0 V=black, -0.3 V sync, sync on green.
Theory of Operation
12-13
Source Theory Overview
The source produces a highly stable and accurate RF output signal by phase
locking a YIG oscillator to a harmonic of the synthesized VCO (voltage controlled
oscillator). The source output produces a CW or swept signal between 300 kHz
and 1.3 GHz (3 GHz for Option 003 and 6 GHz for Option 006). The maximum
leveled power is + 5 dBm. Option 004 analyzers have a 70 dB step attenuator
built into the source that allows the power to be decreased to -85 dBm and
increased to a maximum leveled power of + 10 dBm.
The full frequency range of the source is produced in 13 subsweeps, two in low
band and eleven in high band. The high band frequencies start at 16 MHz and
go up to 1.3 GHz (3 GHz for Option 003 and 6 GHz for Option 006). The high
band frequencies are achieved by harmonic mixing with a different harmonic
number for each subsweep. The low band frequencies (300 kHz to 16 MHz) are
down-converted by fundamental mixing.
The source functional group consists of the individual assemblies described
below.
A14/A13 Fractional-N
These two assemblies comprise the synthesizer. The 30 to 60 MHz VCO in
the Al4 assembly generates the stable LO frequencies for fundamental and
harmonic mixing.
Al2 Reference
This assembly provides stable reference frequencies to the rest of the
instrument by dividing down the output of a 40 MHz crystal oscillator. In low
band operation, the output of the fractional-N synthesizer is mixed down in the
Al2 reference assembly. (The 2nd LO signal from the Al2 assembly is explained
in “Receiver Theory” .)
A7 Pulse Generator
A step recovery diode in the pulse generator produces a comb of harmonic
multiples of the VCO output. These harmonics provide the high band LO (local
oscillator) input to the samplers. In low band operation the pulse generator is
turned off.
12-14
Theory of Operation
All Phase Lock
This assembly compares the first IF (derived from the source output in the A4 R
sampler) to a stable reference, and generates an error voltage that is integrated
into the drive for the A3 source assembly.
A3 Source
This assembly includes a 3.0 to 6.8 GHz YIG oscillator and a 3.8 GHz cavity
oscillator. The outputs of these oscillators are mixed to produce the RF output
signal. In Option 006 (300 kHz to 6 GHz) the frequencies 3.0 to 6.0 GHz are no
longer a mixed product, but are the direct output of the YIG oscillator. The
signal tracks the stable output of the synthesizer. The ALC (automatic leveling
control) circuitry is also in the A3 assembly.
Theory of Operation
12-15
Source Low Band Operation
The low band frequency range is 300 kHz to 16 MHz. These frequencies are
generated by locking the A3 source to a reference signal. The reference signal
is synthesized by mixing down the fundamental output of the fractional-N VCO
with a 40 MHz crystal reference signal. Low band operation differs from high
band in these respects: The reference frequency for the All phase lock is not a
fixed 1 MHz signal, but varies with the frequency of the fractional-N VCO signal.
The sampler diodes are biased on to pass the signal through to the mixer. The
1st IF signal from the A4 R sampler is not fixed but is identical to the source
output signal and sweeps with it. The following steps outline the low band
sweep sequence, illustrated in Figure 12-4.
1. A signal (FN LO) is generated by the fractional-N VCO. The VCO in the
Al4 fractional-N assembly generates a CW or swept signal that is 40 MHz
greater than the start frequency. The signal is divided down to 100 kHz and
phase locked in the Al3 assembly, as in high band operation.
2. The fractional-N VCO signal is mixed with 40 MHz to produce a
reference signal. The signal (FN LO) from the fractional-N VCO goes to the
A12 reference assembly, where it is mixed with the 40 MHz VCXO (voltage
controlled crystal oscillator). The resulting signal is the reference to the
phase comparator in the All assembly.
3. The A3 source is pretuned. The source output is fed to the A4 R
sampler/mixer. The pretuned DAC in the All phase lock assembly sets
the A3 source to a frequency 1 to 6 MHz above the start frequency. This
signal (source output) is applied to the A4 R sampler/mixer assembly via the
coupled arm of the A30 dual directional coupler.
4. The signal from the source is fed back (1st IF) to the phase comparator.
The source output signal passes directly through the R sampler in the A4
assembly, because the sampler is biased on. The signal (1st IF) is fed back
unaltered to the phase comparator in the All phase lock assembly. The other
input to the phase comparator is the heterodyned reference signal from the
A12 assembly. Any frequency difference between these two signals produces
a proportional error voltage.
5. A tuning signal (YO DRIVE) tunes the source and phase lock is achieved.
The error voltage is used to drive the A3 source YIG oscillator to bring the
YIG closer to the reference frequency. The loop process continues until the
source frequency and the reference frequency are the same and phase lock is
achieved.
12-16
Theory of Operation
6 . A synthesized sub sweep is generated. The source tracks the
synthesizer. When phase lock is achieved at the start frequency, the
synthesizer starts to sweep. This changes the phase lock reference frequency
and causes the source to track at a difference frequency 40 MHz below the
synthesizer.
sh6106c
Figure 12-4. Low Band Operation of the Source
Theory of Operation
12-17
The full low band is produced in two subsweeps, to allow addition IF filtering
below 3 MHz . At the transition between subsweeps, the source is pretuned
and then relocks. Table 12-1 lists the low band subsweep frequencies at the
fractional-N VCO and the source output.
Table 12-1. Low Band Subsweep Frequencies
Fractional-N (MHz)
12-18
1st IF (MHz)
Source Output (MHz)
40.3 too43.3
0.3 too3.3
0.3 too3.3
43.3 to 56.0
3.3 to 16.0
3.3 to 16.0
Theory of Operation
Source High Band Operation
The high band frequency range is 16 MHz to 1.3 GHz (3.0 GHz for Option 003
and 6.0 GHz for Option 006). These frequencies are generated in subsweeps by
phase-locking the A3 source signal to harmonic multiples of the fractional-N
VCO. The high band subsweep sequence, illustrated in Figure 12-5, follows these
steps:
1. A signal (III OUT) is generated by the fractional-N VCO. The VCO in the
Al4 fractional-N assembly generates a CW or swept signal in the range of
30 to 60 MHz. This signal is synthesized and phase locked to a 100 kHz
reference signal from the A12 reference assembly. The signal from the
fractional-N VCO is divided by 1 or 2, and goes to the pulse generator.
2. A comb of harmonics (1st LO) is produced in the A7 pulse generator.
The divided-down signal from the fractional-N VCO drives a step recovery
diode (SRD) in the A7 pulse generator assembly. The SRD multiplies
the fundamental signal from the fractional-N into a comb of harmonic
frequencies. The harmonics are used as the 1st LO (local oscillator) signal to
the samplers. One of the harmonic signals is 1 MHz below the start signal set
from the front panel.
3. The A3 source is pretuned. The source output is fed to the A4 R
sample/mixer. The pretune DAC in the All phase lock assembly sets the A3
source to a first approximation frequency (1 to 6 MHz higher than the start
frequency). This signal (RF OUT) goes to the A4 R sampler/mixer assembly
via the coupled arm of the dual directional coupler.
4. The synthesizer signal and the source signal are combined by the
sampler. A difference frequency is generated. In the A4 R sampler, the 1st
LO signal from the pulse generator is combined with the source output signal.
The IF (intermediate frequency) produced is a first approximation of 1 MHz.
The 1st IF is routed back to the All phase lock assembly.
5. The difference frequency (1st IF) from the A4 R sampler is compared to
a reference. The 1st IF feedback signal from the A4 is filtered and applied to
a phase comparator circuit in the All phase lock assembly. The other input
to the phase comparator is a crystal-controlled 1 MHz signal from the A12
reference assembly. Any frequency difference between these two signals
produces a proportional error voltage.
Theory of Operation
12-19
6. A tuning signal (YO DRIVE) tunes the source and phase lock is achieved.
The error voltage is used to drive the A3 source YIG oscillator, in order to
bring it closer to the required frequency. The loop process continues until
the 1st IF feedback signal to the phase comparator is equal to the 1 MHz
reference signal, and phase lock is achieved.
7. A synthesized subsweep is generated by A13/A14. The A3 source tracks
the synthesizer. When the source is phase locked to the synthesizer at the
start frequency, the synthesizer starts to sweep. The phase locked loop forces
the source to track the synthesizer, maintaining a constant 1 MHz 1st IF
signal.
The full high band sweep is generated in a series of subsweeps, by phase
locking the A3 source signal to harmonic multiples of the fractional-N VCO.
The 16 to 31 MHz subsweep is produced by a one-half harmonic, using
the divide-by-2 circuit on the Al4 assembly. At the transitions between
subsweeps, the source is pretuned and then relocks. Table 12-2 lists the high
band subsweep frequencies from the fractional-N VCO and the source output.
12-20
Theory of Operation
sh6107c
Figure 12-5. High Band Operation of the Source
Theory of Operation
12-21
Table 12-2. High Band Subsweep Frequencies
Fractional-N (MHz) Harmonic Source Output (MHz)
12-22
30 to 60
1/2
16 to 31
30 to 60
1
31 to 61
30 to 60
2
61 to 121
40 to 59
3
121 to 178
35.4 to 59.2
5
178 to 296
32.8 to 59.4
9
296 to 536
35.7 to 59.5
15
536 to 893
33.0 to 59.5
27
893 to 1607
31.5 to 58.8
51
1607 to 3000
37.0 to 59.6
83
3000 to 4950
49.0 to 59.4
101
4950 to 6000
Theory of Operation
Signal Separation
The A30 Dual Directional Coupler
Signal separation in the analyzer is accomplished with a dual directional coupler
which, by itself, comprises the analyzer’s built-in test set. The dual directional
coupler is connected to the reflection test port. It is used to separate the
incident signal going to the device under test from reflected signal coming from
the device under test. The incident signal is applied to the R sampler/mixer via
one of coupled arms of the dual directional coupler. Meanwhile, the reflected
signal is routed from the reflection test port via the other coupled arm of the
dual directional coupler to the input of the A sampler/mixer in the receiver.
The transmitted signal is fed directly from the transmission test port to the B
sampler/mixer. (Analyzers having Option 006 have an 8 dB pad between the
transmission test port and the B sampler/mixer.)
Receiver Theory
The receiver functional group consists of the following assemblies:
A4 R sampler/mixer
A5 A sampler/mixer
A6 B sampler/mixer
Al0 digital IF
These assemblies combine with the A9 CPU (described in “Digital Control
Theory”) to measure and process input signals into digital information for
display on the analyzer. Figure 12-6 through Figure 12-9 are simplified block
diagrams of the different receiver functional groups for the various analyzer
options.
Theory of Operation
12-23
|A10 DIGITAL IF
sh6108c
Figure 12-6. Receiver Functional Group (standard and Option 003)
12-24
Theory of Operation
sh6109c
Figure 12-7. Receiver Functional Group (Option 003 and 004)
Theory of Operation
12-25
Figure 12-8. Receiver Functional Group (Option 006)
12-26
Theory of Operation
sh6110c
Figure 12-9. Receiver Functional Group (Option 004 and 006)
Theory of Operation
12-27
A4/A5/A6 Sampler/Mixer
The A4, A5, and A6 sampler/mixers all down-convert the RF input signals to
fixed 4 kHz 2nd IF signals with amplitude and phase corresponding to the RF
input. For the analyzer with with Option 006, the A6 B sampler/mixer assembly
includes an 8 dB gain preamplifier in front of the sampler. This improves the
noise figure performance of the analyzer’s receiver channel B.
The Sampler Circuit in High Band
In high band operation, the sampling rate of the samplers is controlled by
the 1st LO from the A7 pulse generator assembly. The 1st LO is a comb of
harmonics produced by a step recovery diode driven by the fractional-N VCO
fundamental signal. One of the harmonic signals is 1 MHz below the start
frequency set at the front panel. The 1st LO is combined in the samplers with
the source output signal. In options 003 and 006, samplers are additionally
capable of receiving RF input signals up to 3 and 6 GHz respectively. The mixing
products are filtered, so that the only remaining response is the difference
between the source frequency and the harmonic 1 MHz below it. This fixed
1 MHz signal is the 1st IF. Part of the 1st IF signal from the A4 R sampler is fed
back to the All phase lock assembly.
The Sampler Circuit in Low Band
In low band the sampler diodes are biased continuously on, so that the RF input
signal passes through them unchanged. Thus the 1st IF is identical to the RF
output signal from the source (300 kHz to 16 MHz), and sweeps with it. Part
of the 1st IF signal from the A4 R sampler is fed back to the All phase lock
assembly.
(Refer to “Source Theory Overview” for information on high band and low band
operation of the source.)
The 2nd LO Signal
The 2nd LO is obtained from the A12 reference assembly. In high band, the 2nd
LO is fixed at 996 kHz. This is produced by feeding the 39.84 MHz output of a
phase-locked oscillator in the Al2 assembly through a divide-by-40 circuit.
In low band, the 2nd LO is a variable frequency produced by mixing the output
of the fractional-N VCO with a fixed 39.996 MHz signal in the Al2 assembly.
The 2nd LO covers the range of 0.014 to 16.004 MHz in two subsweeps that
correspond with the source subsweeps. These subsweeps are 0.304 to 3.304 MHz
and 3.304 to 16.004 MHz.
12-28
Theory of Operation
The Mixer Circuit
The 1st IF and the 2nd LO are combined in the mixer circuit. The resulting
difference frequency (the 2nd IF) is a constant 4 kHz in both bands, as
Table 12-3 shows.
Table 12-3. Mixer Frequencies
Band
Low
High
1st IF
0.300 to 16.0 MHz
1.000 MHz
2nd LO
2nd IF
0.304 to 16.004 MHz
0.996 MHz
4.0kHz
4.0kHz
A10 Digital IF
The three 4 kHz 2nd IF signals from the sampler/mixer assemblies are input
to the A10 digital IF assembly. These signals are sampled at a 16 kHz rate. A
fourth input is the analog bus, which can monitor either an external input at
the rear panel AUX IN connector or one of 31 internal nodes. A multiplexer
sequentially directs each of the signals to the ADC (analog-to-digital converter).
Here they are converted to digital form and sent to the A9 CPU assembly for
processing. Refer to “Digital Control Theory” for more information on signal
processing.
Theory of Operation
12-29
13
Replaceable Parts
This chapter contains information for ordering replacement parts for the
HP 8752C network analyzer. Replaceable parts include the following:
-
n
major assemblies
n
cables
chassis hardware
In general, parts of major assemblies are not listed. Refer to “Abbreviations” at
the back of this chapter to help interpret part descriptions in the replaceable
parts lists that follow.
Replaceable Parts
13-1
Assembly Replacement Sequence
The following steps show the sequence to replace an assembly in an HP 8752C
Network Analyzer.
1. Identify the faulty group. Refer to the “Start Troubleshooting Here” chapter.
Follow up with the appropriate troubleshooting chapter that identifies the
faulty assembly.
2. Order a replacement assembly. Refer to the “Replaceable Parts” chapter.
3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to the “Assembly Replacement and Post-Repair Procedures” chapter.
4. Perform the necessary adjustments. Refer to the “Adjustments and
Correction Constants” chapter.
5. Perform the necessary performance tests. Refer to the “System Verification
and Performance Tests” chapter.
Save Money with Rebuilt-Exchange Assemblies
Under the rebuilt-exchange assembly program, certain factory-repaired and
tested modules (assemblies) are available on a trade-in basis. These assemblies
cost less than a new assembly, and meet all factory specifications required of a
new assembly.
The defective assembly must be returned for credit under the terms of the
rebuilt-exchange assembly program. Figure 13-1 illustrates the module exchange
procedure. “Major Assemblies” shows all major assemblies, including those that
can be replaced on an exchange basis.
13-2
Replaceable Parts
The module exchange program described here is a fast, efficient, economical
method of keeping your Hewlett-Packard instrument in service.
A.
Locate defective module
using troubleshooting
procedures in this
manual
R e s t o r e d - e x c h a n g e m o d u l e s are
s h i p p e d individually in boxes like
this. In addition to the circuit
m o d u l e , t h e b o x contains:
Exchange assembly failure report
Return address label
Is a replacement
m o d u l e o n hand?
NO
Open box carefully-it will be
used to return defective module
to HP. Complete failure report.
Place it and defective module
i n b o x . B e s u r e t o remove
enclosed return address label
Return defective module
to HP.
Return defective module
to HP.
Seal box with tape. Inside
U.S.A. *, stick preprinted return
a d d r e s s l a b e l over label a l r e a d y
on box, a n d r e t u r n b o x t o H P .
Outside U.S.A., do not use address label: instead address box
to the nearest HP office.
sg613d
Figure 13-1. Module Exchange Procedure
Replaceable Parts
13-3
Gather This Information Before Ordering
To order a part listed in the replaceable parts lists:
1. Determine the part number.
2. Determine the quantity required.
3. Mail this information to the nearest Hewlett-Packard office or, in the U.S.,
call the hotline number listed in the following section.
To order a part not listed in the replaceable parts lists:
1. Note the instrument model number (HP 8752C).
2. Note the serial number and options, if any (see rear panel).
3. Describe the part.
4. Describe the function of the part.
5. Determine the quantity required.
6. Mail this information to the nearest Hewlett-Packard office or, in the U.S.,
call the hotline number listed in the following section.
Call (800) 227-8164 to Order Parts Fast (U.S. only)
When you have gathered the information required to place an order, contact
Hewlett-Packard’s direct ordering team by calling the following toll-free hotline
number:
(800) 227-8164
Monday through Friday, 6 AM to 5 PM (Pacific Standard Time)
The parts specialists have direct online access to replacement parts inventory
corresponding to the replaceable parts lists in this manual. Four day delivery
time is standard; there is a charge for hotline one-day delivery.
This information applies to the United States only. Outside the United States,
contact your nearest HP office.
13-4
Replaceable Parts
Replaceable Part Listings
The following pages list the replacement part numbers and descriptions for
the HP 8753C network analyzer. Illustrations with reference designators
are provided to help identify and locate the part needed. The parts lists are
organized into the following categories:
----------
Major Assemblies
Front Panel Assemblies
Rear Panel Assemblies
Cables, Top View
Front Panel, Cables and Attaching Hardware
Rear Panel, Cables and Attaching Hardware
Source and Sampler Parts: Standard and Option 003
Source and Sampler Parts: Option 004/006
Source and Sampler Parts: Options 004 and 003/004
Source and Sampler Parts: Option 006
Display Bezel Assembly
Chassis Parts
Top View of Attaching Hardware and Post Regulator Fuses
Bottom View of Attaching Hardware
Right View of Attaching Hardware
Left View of Attaching Hardware
Rear Panel Attaching Hardware
Replaceable Labels
Miscellaneous Parts and Accessories
Replaceable Parts
13-5
Major Assemblies
Item
Opt.
HP Part
Number
Qty
41
Description
FRONT PANEL KEYBOARD ASSY (see “Front Panel Assemblies”)
42
FRONT PANEL INTERFACE ASSY (see “Front Panel Assemblies”)
43
SOURCE ASSY (see “Source and Sampler Parts”)
44
R SAMPLER ASSY (see “Source and Sampler Parts”)
45
A SAMPLER ASSY (see “Source and Sampler Parts”)
B SAMPLER ASSY (see “Source and Sampler Parts”)
46
08753-60007
47
1
08753-60208
48
PULSE GENERATOR BD ASSY
PULSE GENERATOR BD ASSY (Rebuilt-Exchange) (includes board cover)
08753-69007
1
POST REGULATOR BD ASSY
POST REGULATOR BD ASSY (Rebuilt-Exchange)
08753-69208
CPU BD ASSY
A9
08752-60016
1
A9BT1
1420-0394
1
BATTERY-LITHIUM 3V 1A (not shown)
A10
08753-60095
1
DIGITAL IF BD ASSY
All
08753-60162
Al2
08752-60023 1
Al3
08753-60013
DIGITAL IF BD ASSY (Rebuilt-Exchange)
08753-69095
1
1
Al4
08753-60068
1
Al5
08753-60098
1
FRACTIONAL-N DIGITAL BD ASSY
PREREGULATOR
REAR PANEL BD ASSY (see “Rear Panel Assemblies”)
A16
08753-60130
Al7
2090-0210
A18
1
1
A19
08763-60170
1
A30
5086-7955
1
076
5086-7557
5086-6557
DISPLAY ASSY
GRAPHICS SYSTEM PROCESSOR (GSP) ASSY
600 DUAL DIRECTIONAL COUPLER*
50 ohm COUPLER* (Rebuilt-Exchange)
5086-6955
076
MOTHERBOARD ASSY REPLACEMENT KIT (includes motherboard, card
cage, and corner struts)
DISPLAY ASSY (Rebuilt-Exchange)
5180-8484
1
75 ohm DUAL DIRECTIONAL COUPLER*
75 ohm COUPLER” (Rebuilt-Exchange)
8 dB ATTENUATOR (see “Source and Sampler Parts”)
006
08763-60047
1
FAN ASSEMBLY
* includes bracket and front panel connectors
13-6
ASSY
PREREGULATOR ASSY (Rebuilt-Exchange)
08753-69098
B1
FRACTIONAL-N ANALOG BD ASSY
FRACTIONAL-N ANALOG BD ASSY (Rebuilt-Exchange)
08753-69013
AT1
PHASE LOCK BD ASSY
REFERENCE BD ASSY
Replaceable Parts
Major Assemblies
Al6
(NOT VISIBLE)
415
A8
(NOT
A17
VISIBLE)
A9
A3
A-l
A10
All
Al2
Al3
A14
A4
A30
A5
A6
(NOT VISIBLE)
( NOT
sh65c
Replaceable Parts
13-7
Front Panel Assemblies
Item
Opt.
1
HP Part
Number
Qty
Description
08752-60029
1
0875260030
1
2
2190-0016
3
WASHER-LOCK INTERNAL T 3/8 INCH 0.377-INCH-ID
3
2950-0043
3
NUT-HEX-DOUBLE CHAMFER 3/8-32-THREAD
4
01660-47401
1
RPG KNOB
5*
0515-0374
6
SCREW-MACHINE M3.0x 10 CW-PN-TX
1
075
503 FRONT DRESS PANEL
75 ohm FRONT DRESS PANEL
6
08752-4000.
1
KEYPAD, RUBBER
7*
0515-1410
2
SCREW-MACHINE M3.0 x 20 CW-PN-TX
8*
05150375
2
SCREW-MACHINE M3.0 x 16 CW-PN-TX
A1
08753-60140
1
FRONT PANEL KEYBOARD ASSY
RIBBON CA ASSY, Al to A2 (p/o Al) (see “Cables, Top View”)
A1W1
A2
08763-60091
1
FRONT PANEL INTERFACE BD ASSY
RPG1
08757-60053
1
ROTARY PULSE GENERATOR (RPG)
W18
08711-60037
1
PROBE POWER CA ASSY, A2 to FRONT PANEL
* Metric hardware: other thread types will damage threaded holes.
13-8
Replaceable Parts
Front Panel Assemblies
(2 PLACES)
not visible
not visible
connects RPG1
not visible
A1
sh610c
Replaceable Parts
13-9
Rear Panel Assemblies
Item
Opt.
HP Part
Number
Qty
1
Description
REAR FRAME (see “Chassis Parts”)
2
2190-0584
4
3*
0515-0965
4
SCREW-SOCKET-HEAD-CAP M3 x 0.6 14MM-LONG
4
08753-20040
1
FAN GASKET
5
08753-00047
1
REAR PANEL
A16
08752-60013
1
REAR PANEL B D ASSY (includes A16W1
B1
08753-60047
1
FAN (includes cable assembly)
W18
WASHER-LOCK HELICAL 3.0 MM 3.1-MM-ID
CA ASSY, REAR PANEL to Al2 (see “Cables, Top View”)
* Metric hardware: other thread types will damage threaded holes.
13-10
Replaceable Parts
Rear Panel Assemblies
(4
PLACES)
4
A16
(INSIDE)
sh612c
Replaceable Parts
13-11
Cables, Top View
Item
Opt.
HP Part
Number
Qty
Description
A18W1
p/o A18
1
CA ASSY, A18 to A19
W1
08752-20021
1
SEMI-RIGID CA ASSY, A3 to A30 (see “Front Panel, Cables and Attaching
Hardware”)
W2
5021-8770
1
SEMI-RIGID CA ASSY, A30 to A4
W3
5021-8771
1
SEMI-RIGID CA ASSY, A30 to A5
W4
08753-20030
1
SEMI-RIGID CA ASSY. RF IN to A6
W5
08753-60027
1
FLX RF CA ASSY, A7 to A4
W6
08753-60027
1
FLX RF CA ASSY, A7 to A6
W7
08753-60027
1
FLX RF CA ASSY, A7 to A6
W8
08753-60061
1
FLX RF CA ASSY, A4 to All
W9
08753-60061
1
FLX RF CA ASSY, Al4 to A7
W10
08753-60029
1
FLX RF CA ASSY, Al4 to Al2
W11
08763-60029
1
FLX RF CA ASSY, Al4 to Al3
W12
08753-60029
1
FLX RF CA ASSY, Al2 to Al3
W13
08753-60026
1
FLX RF CA ASSY, Al6 to Al2
W14
08763-60113
1
DISPLAY POWER CA ASSY, A8 to A19
08513-60036
1
CA ASSY, A9 to Al9
W20
13-12
Replaceable Parts
Cables, Top View
W1
W5
W2
(W32 Opt004)
W6
W3
W7
W4
(W34 Opt006)
W10
W11
W12
sh68c
Replaceable Parts
13-13
Front Panel, Cables and Attaching Hardware
Item
Opt.
HP Part
Number
Qty
Description
1*
0515-0458
3
SCREW-MACHINE M3.5x 8 CW-PN-TX
W1
5021-8769
1
SEMI-RIGID CA ASSY, A3 to A30
W3
5021-8771
1
W17
08763-60033
1
RIBBON CA ASSY, A2 to A17
1260-2189
1
CA ASSY, A30 to REFLECTION PORT
1250-2311
1
CA ASSY, A30 to REFLECTION PORT
W50
W75
075
SEMI-RIGID CA ASSY, A30 to A5
* Metric hardware: other thread types will damage threaded holes.
Note
13-14
The cables described on this page are common to all instrument
options. For option specific cables refer to the “Source and
Sampler Parts” section for your option.
Replaceable Parts
Front Panel Cables and Attaching Hardware
W17
W50 or W75
(BEHIND)
W3
(3 PLACES)
sh63c
Replaceable Parts
13-15
Rear Panel, Cables and Attaching Hardware
Item
Qty
Description
SCREW-MACHINE M3.0x 14 SH-HX
1*
2
WASHER-LOCK M3.0 NOM
A15W1
CA ASSY, Al5 to A8 and Al7
A16W1
08753-60033
RIBBON CA ASSY, Al6 to Al7 (p/o A16)
W13
08753-60026
FLX RF CA ASSY, REAR PANEL to A12
W21
08753-60117
FLX RF CA ASSY, RED (p/o A16)
W22
08753-60118
FLX RF CA ASSY, GREEN (p/o A16)
W23
08753-60119
1
FLX RF CA ASSY, BLUE (p/o A16)
* Metric hardware: other thread types will damage threaded holes.
13-16
Replaceable Parts
Rear Panel Cables and Attaching Hardware
sh613c
Replaceable Parts
13-17
Source and Sampler Parts: Standard and Option 003
Item
HP Part
Number
Qty
1
Description
A3
08753-60234
A3
08753-69234
A3MP1
1250-0590
1
SMB CAP
A3W1
08753-20107
1
RF CA, SEMI-RIGID, EYO (A3A3) to SOURCE (A3)
A3W2
08753-20032
1
RF CA, SEMI-RIGID, CAV OSC A 3 A 4 ) to SOURCE (A3)
A3A2W1
08753-60034
1
RIBBON CA ASSY, EYO (A3A3) to ALC (A3A2)
A3W7
08752-20024
1
A4
08753-60004
1
A5
08753-60004
1
A SAMPLER ASSY
A6
08753-60004
1
B SAMPLER ASSY
Wl
08752-20021
1
RF CA, SOURCE (A3) to COUPLER (A30)
W2
5021-8770
1
RF CA, COUPLER (A30) to R SAMPLER (A4)
W3
5021-8771
1
RF CA, COUPLER (A30) to A SAMPLER (AS)
W4
08753-20030
1
RF CA, TRANSMISSION PORT to B SAMPLER (A6)
13-18
Replaceable Parts
SOURCE ASSY
SOURCE ASSY (Rebuilt-Exchange)
RF CA, 4 dB ATTENUATOR (A3AT1) to BULKHEAD (A3 OUTPUT)
R SAMPLER ASSY
Source and Sampler Parts: Standard and Option 003
W1
A4
A5
W3
A6
W4
W2
SAMPLERS AND FRONT PANEL CABLES
sh6130c
A3MP1
A3A2W1
A3W1
A3W2
A3 SOURCE CABLES
Replaceable Parts
13-19
Source and Sampler Parts: Option 004/006
Item
HP Part
Number
Qty
1
1250-0590
A3
08753-60146
A3
08763-69146
A3W1
08753-20107
1
RF CA, SEMI-RIGID, EYO ( A 3 A 3 to SOURCE (A3)
A3W2
08753-20032
1
RF CA, SEMI-RIGID, CAV OSC (A3A4) to SOURCE (A3)
A3A2W1
08753-60034
1
RIBBON CA ASSY, EYO (A3A3) to ALC (A3A2)
A3W3
08753-20106
1
RF CA, SOURCE (A3) to 70 dB STEP ATTENUATOR (A3A5)
A3W4
08763-20111
1
AT1
0956-0206
1
8 dB ATTENUATOR (connects to B sampler)
A4
08753-60004
1
R SAMPLER ASSY
A5
08763-60004
1
A SAMPLER ASSY
A6
08753-60169
1
B SAMPLER ASSY
W1
08752-20021
1
RF CA, SOURCE (A3) to COUPLER (A30)
W3
6021-8771
1
RF CA, COUPLER (A30) to A SAMPLER (A5)
W32
08752-20022
1
RF CA, SOURCE (A3) to R SAMPLER (A4)
W34
08752-20023
1
RF CA, TRANSMISSION PORT to 8 dB ATTENUATOR (AT1)
13-20
Replaceable Parts
1
Description
1
SMB CAP (used on coupler)
SOURCE ASSY
SOURCE ASSY (Rebuilt-Exchange)
RF CA, 70 dB STEP ATTENUATOR (A3A5) to BULKHEAD (A3 OUTPUT)
Source and Sampler Parts: Option 004/006
W1
SAMPLERS
A3W4
AND
W3
FRONT
A3W3
PANEL
CABLES
A3W4
A3A2W1
A3W1
A3W5
A3W2
A3 SOURCE C A B L E S
Replaceable Parts
13-21
Source and Sampler Parts: Options 004 and 003/004
Item
HP Part
Number
Qty
Description
1
1250-0590
1
SMB CAP
A3
08753-60231
1
SOURCE ASSY
A3
08753-69231
A3W1
08753-20107
1
A3W2
08753-20032
1
RF CA, SEMI-RIGID, CAV OSC (A3A4) to SOURCE (A3)
A3A2W1
08753-60034
1
RIBBON CA ASSY, EYO (A3A3) to ALC (A3A2)
A3W3
08753-20106
1
RF CA, SOURCE (A3) to 70 dB STEP ATTENUATOR (A3A5)
A3W4
08753-20111
1
RF CA, 70 dB STEP ATTENUATOR (A3A5) to BULKHEAD (A3 OUTPUT)
A4
08753-60004
1
R SAMPLER ASSY
A5
08753-60004
1
A SAMPLER ASSY
A6
08753-60004
1
B SAMPLER ASSY
W1
08752-20021
1
RF CA, SOURCE (A3) to COUPLER (A30)
W3
5021-8771
1
RF CA, COUPLER (A30) to A SAMPLER (A6)
W4
08763-20030
1
RF CA, TRANSMISSION PORT to B SAMPLER (A)
W32
08752-20022
1
RF CA, SOURCE (A3) to R SAMPLER (A4)
13-22
Replaceable Parts
SOURCE ASSY (Rebuilt-Exchange)
RF CA, SEMI-RIGID, EYO (A3A3) to SOURCE (A3)
Source and Sampler Parts: Options 004 and 003/004
W4
W32
(1)
W1
SAMPLERS
AND
W3
FRONT
A3W4
PANEL
CABLES
sh6136c
A3W4
A3A2W1
A3W1
A3W5
A3W2
A3 SOURCE CABLES
Replaceable Parts
13-23
Source and Sampler Parts: Option 006
Item
HP Part
Number
Qty
1
Description
A3
08753-60233
A3
08753-69233
SOURCE ASSY
A3MP1
1250-0590
SMB CAP
A3W1
08753-20107
RF CA, SEMI-RIGID, EYO (A3A3) to SOURCE (A3)
A3W2
08753-20032
RF CA, SEMI-RIGID, CAV OSC ( A 3 A 4 ) to SOURCE (A3)
A3A2W1
08753-60034
RIBBON CA A S S Y , EYO (A3A3) to ALC (A3A2)
SOURCE ASSY (Rebuilt-Exchange)
RF CA, 4 dB ATTENUATOR (A3AT1) to BULKHEAD (A3 OUTPUT)
A3W7
08752-20024
A4
08753-60004
R SAMPLER ASSY
A5
08753-60004
A SAMPLER ASSY
A6
08753-60169
W1
08752-20021
1
RF CA, SOURCE (A3) to COUPLER (A30)
W2
5021-8770
1
RF CA, COUPLER (A30) to R SAMPLER (A4)
W3
5021-8771
1
RF CA, COUPLER (A30) to A SAMPLER (AS)
W34
08762-20023
1
RF CA, TRANSMISSION PORT to 8 dB ATTENUATOR (AT1)
13-24
Replaceable Parts
B SAMPLER ASSY
Source and Sampler Parts: Option 006
A4
A5
A6
AT1 (not visible)
W34
W3
W2
SAMPLERS AND FRONT PANEL CABLES
A3W1
A3W2
A3
SOURCE
CABLES
sh6205c
Replaceable Parts
13-25
Display Bezel Assembly
Item
Opt.
HP Part
Number
Qty
Description
1
08757-40012
1
SOFTKEYS COVER
2
5062-7208
1
BEZEL ASSY (nameplate must be ordered separately)
3*
0515-2113
4
2
SCREW-MACHINE M4.0x8 PC-PN-TX
08752-80032
1
NAMEPLATE 8752C
4
003
08752-80034
1
NAMEPLATE 87526 OPTION 003
4
006
08752-80036
1
NAMEPLATE 8752C OPTION 006
08757-40003
1
BEZEL SUPPORT
5
* Metric hardware: other thread types will damage threaded holes.
13-26
Replaceable Parts
Display Bezel Assembly
HOWN)
Replecaable Parts
13-27
Chassis Parts
Item
HP Part
Number
Qty
Description
1
5062-3735
1
COVER, TOP ASSY
2
5021-5806
1
REAR FRAME
3
5062-3842
1
COVER-SIDE (for use with strap handle)
4
5062-3704
1
STRAP HANDLE 18 INCH
5
5041-8820
1
STRAP, HANDLE, CAP-REAR
6*
0515-1384
2
SCREW-MACHINE M5.0 x10 PC-FL-TX
7
5001-0540
2
TRIM, SIDE (used when front handles are removed)
8
5041-8819
1
STRAP, HANDLE, CAP-FRONT
9
1460-1345
2
TILT STAND
10
5041-8801
4
FOOT (STANDARD)
11
5062-3747
1
COVER, BOTTOM ASSY (order item 11A also)
11A
08753-20039
1
BOTTOM COVER MYLAR INSULATOR (not shown)
12
5062-3817
1
COVER-SIDE-PERF
13
5041-8802
1
TRIM, TOP
14
5062-3990
1
FRONT HANDLE KIT (for rack mount options)
15
6041-8821
4
REAR STANDOFF
16*
0616-1402
4
SCREW-MACHINE M3.5x8 PC-PN-TX
17
5021-8405
1
FRONT FRAME
* Metric hardware: other thread types will damage threaded holes.
NOTE: See “Miscellaneous Parts and Accessories” for touch-up paint.
13-28
Replaceable Parts
Chassis Parts
sh627c
Replaceable Parts
13-29
Top View of Attaching Hardware and Post Regulator Fuses
Ref. Desig.
HP Part
Number
Qty
Description
1*
0515-2086
1
SCREW-MACHINE M4.0x7 PC-FL-TX
2*
0515-1400
2
SCREW-MACHINE M3.5x8 PC-FL-TX
3*
0515-0374
15
4*
1
0515-2035
SCREW-MACHINE M3.0x10 CW-PN-TX
SCREW-MACHINE M3.0x16 PC-FL-TX
5*
0515-0458
2
SCREW-MACHINE M3.5x8 CW-PN-TX
SCREW-MACHINE M3.5x10 CW-PN-TX
6*
0515-0377
2
7*
0515-0390
3
SCREW-MACHINE M4.0x6 CW-FL-TX
8*
0515-0433
1
SCREW-MACHINE M4.0x8 CW-FL-TX
9*
0515-0664
1
SCREW-MACHINE M3.0x12 CW-PN-TX
10
3050-0891
1
WASHER-FLAT M3.0 NOM
A8F1
2110-0425
1
FUSE 2A 125V NTD 0.25x0.27
A8F2
2 1 lo-0424
1
FUSE 0.75A 125V NTD 0.25x0.27
A8F3
2110-0425
1
FUSE 2A 125V NTD 0.25x0.27
A8F4
2110-0424
1
FUSE 0.75A 125V NTD 0.26x0.27
A8F5
2110-0476
1
FUSE 4A 125V NTD 0.25x0.27
A8F6
2110-0425
1
FUSE 2A 125V NTD 0.25x0.27
A8F7
2110-0476
1
FUSE 4A 126V NTD 0.25x0.27
A8F8
2110-0047
1
FUSE 1A 125V NTD 0.26x0.27
A8F9
2110.0046
1
FUSE 0.5A 125V NTD 0.26x0.27
MP1
08753-00039
1
A6 ISOLATION GROUNDING CLIP
MP2
08753-00040
1
A7 ISOLATION GROUNDING SHIELD
MP3
08753-40006
1
PC BOARD STABILIZER-BAR
08753-20062
1
PC BOARD STABILIZER-CAP
*
0515-0374
2
SCREW-MACHINE M3.0x10 CW-PN-TX (attaches cap to bar)
MP4
08753-00044
1
SOURCE RETAINER BRACKET
* Metric hardware: other thread types will damage threaded holes.
13-30
Replaceable Parts
Top View of Attaching Hardware and Post Regulator Fuses
(2 PLACES)
A8F3
A8F4
(UNDERNEATH)
A8F5
MP3
(4 PIECES
CAP, BAR,
2 SCREWS)
A8F6
A8F7
A8F8
(15 PLACES)
A 8 F 9
(3 PLACES)
Replaceable Parts
13-31
Bottom View of Attaching Hardware
Item
HP Part
Number
Qty
1*
0515-1400
2
5180-8500
1
3*
0515-0377
2
4*
0515-0458
2
Al7
5
Description
SCREW-MACHINE M3.5x8 PC-FL-TX
INSULATOR
SCREW-MACHINE M3.5x10 CW-PN-TX
SCREW-MACHINE M3.5x8 CW-PN-TX
MOTHERBOARD ASSY (see “Major Assemblies”)
* Metric hardware: other thread types will damage threaded holes.
13-32
Replaceable Parts
Bottom View of Attaching Hardware
A17
(5
PLACES)
(UNDERNEATH)
Replaceable Parts
13-33
Right View of Attaching Hardware
Item
HP Part
Number
Qty
Description
1*
0515-2086
8
SCREW-MACHINE M4.0x7 PC-FL-TX
2*
0616-1400
1
SCREW-MACHINE M3.5x8 PC-FL-TX
* Metric hardware: other thread types will damage threaded holes.
(8 PLACES)
13-34
Replaceable Parts
Left View of Attaching Hardware
Item
HP Part
Qty
Description
1*
0515-2086
8
SCREW-MACHINE M4.0x7 PC-FL-TX
2*
0515-2086
3
SCREW-MACHINE M4.0x7 PC-FL-TX
3
1460-1573
1
SPRING-EXTENSION .138 OD
4*
0515-0430
1
SCREW-MACHINE M3.0x6 CW-PN-TX
5
08753-00036
1
INSULATOR-SWITCH
6
08753-00048
1
ACTUATOR-LINE SWITCH
7
08767-40005
1
LINE BUTTON
* Metric hardware: other thread types will damage threaded holes.
(11 PLACES)
(1)
sh62c
(NOT VISIBLE)
Replaceable Parts
13-35
Rear Panel Attaching Hardware
Item
HP Part
Number
Qty
Description
1
2190-0102
4
2
2950-0035
7
NUT-HEX-DOUBLE CHAMFER 15/32-32-THREAD
3
2190-0686
2
WASHER-LOCK HELICAL 4.0 MM 4.1-MM-ID
4
0380-0643
2
STANDOFF-HEX 0.255-INCH-LONG 6-32 THREAD
5
1261-2942
2
LOCK-SUBMIN D CONN (includes lockwashers)
6*
0515-0372
3
SCREW-MACHINE M3.0x8 CW-PN-TX
7
2110-0780
1
FUSE 3A 250V NON-TIME DELAY
WASHER-LOCK INTERNAL TEETH 15/32 INCH 0.472-INCH-ID
* Metric hardware: other thread types will damage threaded holes.
(7 PLACES)
SHOWN)
(2
13-36
PLACES)
Replaceable Parts
(3
PLACES)
Replaceable Labels
Item
HP Part
Number
Qty
Description
1
08752-80003
1
LABEL, LOCATION DIAGRAM
2
7120-4296
1
LABEL, HAZARDOUS VOLTAGE WARNING
3
7120-6999
1
LABEL, LINE VOLTAGE SELECTOR SWITCH
4
7121-2527
1
LABEL, METRIC HARDWARE CAUTION
5
08753-80066
1
LABEL, WARNING CAUTION
6
7121-5125
1
TAG, WARNING ESD SENSITIVE
sh616c
Replaceable Parts
13-37
Miscellaneous Parts and Accessories
HP Part Number
Description
ACCESSORIES
5062-4072
13-38
OPT 1CP, RACK MOUNT KIT FOR INSTRUMENTS EQUIPPED WITH HANDLES
0515-1106
REPLACEMENT SCREWS FOR OPT 913
60623978
OPT ICM, RACK MOUNT KIT FOR INSTRUMENTS WITHOUT HANDLES
0516-1114
REPLACEMENT SCREWS, OPT 908
HP 85032B
50 OHM-TYPE N CALIBRATION KIT (OPT 001)
HP 85033C
50 OHM-3.5 MM CALIBRATION KIT (OPT 001)
HP 11852B
50-75 ohm MINIMUM LOSS ATTENUATOR
HP 11853A
50 ohm TYPE-N ADAPTER KIT
HP 11878A
50 ohm 3.6 MM ADAPTER KIT
HP 11864A
50 ohm BNC ADAPTER KIT
HP 11855A
75 ohm TYF’E-N ADAPTER KIT
HP 11856A
75 ohm BNC ADAPTER KIT
8120-5639
50 ohm TYPE-N TEST PORT RETURN CA
8120-2408
75 ohm TYPE-N TEST PORT RETURN CA
9300-0969
ESD WRIST STRAP (SMALL)
9300-1117
ESD WRIST STRAP (MEDIUM)
9300-0970
ESD WRIST STRAP (LARGE)
HP 92176T
ESD TABLE MAT
HP 10833A
HP-IB CA (1 M, 3.3 FEET)
HP 10833B
HP-IB CA (2 M, 6.6 FEET)
HP 10833C
HP-IB CA (4 M, 13.2 FEET)
HP 10833D
HP-IB CA (0.6 M, 1.7 FEET)
HP 92192A
FLOPPY DISKS (box of 10 double-sided 3.6 inch disks)
HP 85043B
SYSTEM RACK MOUNT
Replaceable Parts
Miscellaneous Parts and Accessories
BP Part Number
Description
SOFTWARE
08753-10004
HP 8752C EXAMPLE MEASUREMENT PROGRAM DISK
08753-10005
HP 8752C EXAMPLE MEASUREMENT PROGRAM DISK
08753-60023
HP 8752C TOOL KIT
08752-90134
HP 8752C MANUAL SET includes the following:
SERVICE TOOLS
DOCUMENTATION
08752-90135
HP 8752C USER’S GUIDE (includes Quick Reference, 08752-90138)
08752-90137
HP 8752C PROGRAMMING GUIDE
08752-90139
HP 8752C INSTALLATION & QUICK START GUIDE
08752-90157
HP 8752C SYSTEM VERIFICATION AND PERFORMANCE TESTS
08752-90136
HP 8752C SERVICE GUIDE (this manual)
08752-90158
HP 8752C COMPONENT-LEVEL INFORMATION
HP 11884D
6 GHz UPGRADE KIT (conversion to Opt 006)
UPGRADE KITS
HP 11885A
3 GHz RECEIVER UPGRADE KIT (conversion to Opt 003)
HP 85019C
TIME DOMAIN UPGRADE KIT (conversion to Opt 010)
08752-60019
ATTENUATOR UPGRADE KIT (concversion to Opt 004)
8753A-1
9 EEPROM BACKUP
8753A-5
IMPROVING RELIABILITY OF THE A3 SOURCE ASSEMBLY
6010-1146
DOVE GRAY PAINT (front panel frame, portions of front handles)
6010-1147
FRENCH GRAY (side, top, bottom covers)
6010-1148
PARCHMENT WHITE (rack mount flanges, rack support shelves, front panel;
SERVICE NOTES*
TOUCH-UP PAINT
* To obtain a service note, contact your local HP Service Center.
Replaceable Parts
13-39
Abbreviations
Reference Designations, Abbreviations, and Options
REFERENCE DESIGNATIONS
A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . assembly
B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fan; motor
J . . . . . . . . electrical connector (stationary portion); jack
RPG . . . . . . . . . . . . . . . . . . . . . . . . . . . rotary pulse generator
W . . . . . . . . . . . . . . . . . . . . . cable; transmission path; wire
ABBREVIATIONS
A ........................................
ampere
ALC . . . . . . . . . . . . . . . . . . . . . . . . . automatic level control
ASSY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . assembly
AUX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . auxiliary
BD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . board
CA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cable
COAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . coaxial
CPU . . . . . . . . . . . . . . . . . . . . . . . . .central processing unit
C W . . . . . . . . . . . . . . . . . .conical washer (screws)
D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . diameter
ESD . . . . . . . . . . . . . . . . . . . . . . . . . electrostatic discharge
EXT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . external
EYO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . YIG oscillator
FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . flathead (screws)
FLX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . flexible
FP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . front panel
FRAC-N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fractional N
FREQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . frequency
GHzz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gigahertz
HEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . hexagonal
HP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hewlett-Packard
HP-IB . . . . . . . . . . . . . . . . . Hewlett-Packard interface bus
HX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . hex recess (screws)
ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . inside diameter
IF
. intermediate frequency
I/O
O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . input/output
LED
D . . . . . . . . . . . . . . . . . . . . . . . . . . . . light-emitting diode
13-40
Replaceable Parts
M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . meters
M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . metric hardware
MHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . megahertz
mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . millimeters
MNL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . manual
MON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . monitor
NOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . nominal
. NTD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . non-time delay
NY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . nylon
OD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . outside diameter
Opt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . option
OSC
% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . oscillator
PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . patch lock (screws)
PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . printed circuit
PN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . panhead (screws)
p/oo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . part of
REF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . reference
REPL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . replacement
RF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . radio frequency
RP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . rear panel
SH . . . . . . . . . . . . . . . . . . . . . . . . . socket head cap (screws)
TX . . . . . . . . . . . . . . . . . . . . . . . . . . . TORX recess (screws)
Qty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . quantity
v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . volt
WFR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . wire formed
W/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . without
YIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . yttrium-iron garnet
OPTIONS
003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 GHz performance
004 . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 dB step attenuator
006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 GHz performance
010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . time domain
076 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 ohm test set
14
Assembly Replacement and Post-Repair
Procedures
This chapter contains procedures for removing and replacing the major
assemblies of the HP 8752C network analyzer. A table showing the
corresponding post-repair procedures for each replaced assembly is located at
the end of this chapter.
Procedures described in this chapter consist of the following:
Cover Removal
Initial Front Panel Procedure
Initial Rear Panel Procedure
A1, A2 (keyboard, front panel interface)
A3 (source)
A15, A16 (preregulator, rear panel board)
A18 (display)
A30 (directional coupler)
B1 (fan)
A9BT1 (battery)
Caution
Many of the assemblies in this instrument are very susceptible
to damage from ESD (electrostatic discharge). Perform the
following procedures only at a static-safe workstation and wear
a grounding strap.
Assembly Replacement and Post-Repair Procedures
14-1
Assembly Replacement Sequence
The following steps show the sequence to replace an assembly in an HP 8752C
Network Analyzer.
1. Identify the faulty group. Refer to the “Start Troubleshooting Here” chapter.
Follow up with the appropriate troubleshooting chapter that identifies the
faulty assembly.
2. Order a replacement assembly. Refer to the “Replaceable Parts” chapter.
3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to the “Assembly Replacement and Post-Repair Procedures” chapter.
4. Perform the necessary adjustments. Refer to the “Adjustments and
Correction Constants” chapter.
5. Perform the necessary performance tests. Refer to the “System Verification
and Performance Tests” chapter.
Tools Required
ESD wrist strap and grounding cord
Small flat edge screwdriver
TORX driver
q Number 10
q Number 15
q Number 25
Wrenches, open end:
q 3/16-inch
q 9/32-inch
q 5/16-inch
q 9/16-inch
14-2
Assembly Replacement and Post-Repair Procedures
Cover Removal Procedure
Figure 14-1. Cover Removal Procedure
To remove top cover:
To remove right side cover:
remove screws (1) & upper standoffs (2) remove top cover
loosen screw (3)
remove screw (9) & lower standoff (10)
slide cover off
loosen screw (11)
slide cover back
To remove left side cover:
To remove bottom cover:
remove top cover
remove bottom feet (12)
remove screw (4) & lower standoff (5)
remove screws (4,9) & lower standoffs (5,10)
remove screws (6) & handle (7)
loosen screw (13)
loosen screw (8)
slide cover off
slide cover back
Assembly Replacement and Post-Repair Procedures
14-3
Initial Front Panel Procedure
sh617c
Figure 14-2. Initial Front Panel Procedure
1. Remove the bezel’s softkey cover (item 1, Figure 14-2) by sliding your
fingernail under the left edge, near the top or bottom of the cover.
2. Pry the cover away from the bezel. Do not scratch the glass.
3. Remove the two screws (item 2) exposed by the previous step.
4. Remove the bezel (item 3) from the frame.
5. Remove the trim strip from the top edge of the front frame by prying it with
a flat screwdriver.
6. Remove the two right-most screws from the top edge of the frame (item 4).
14-4
Assembly Replacement and Post-Repair Procedures
Figure 14-3. Location of Screws on Bottom Edge of Frame
7 . Turn the instrument over and remove the right front foot.
8 . Remove the two screws from the bottom edge of the frame (item 5).
9 . Continue with the procedure which referred you to this one.
Assembly Replacement and Post-Repair Procedures
14-5
Initial Rear Panel Procedure
1. Remove the top and bottom covers (see “Cover Removal Procedure”).
2. Remove the PC board stabilizer (item 6, Figure 14-4).
Figure 14-4. Location of EXT REF cable and GSP Assembly
14-6
Assembly Replacement and Post-Repair Procedures
3. Lift the Al2 reference assembly from its motherboard connector and
disconnect the EXT REF coax cable (item 7) from A12J3.
4. Remove the A19 GSP assembly clamp (item 8).
5. Disconnect the RED, GREEN, and BLUE coax cables from the GSP board (you
may need to move the large ribbon cable to access them).
Figure 14-5. Location of Rear Panel Fasteners
6. Remove seven screws from the rear panel assembly: two from the top and
bottom frames (item 9), and three from the back (item 10, Figure 14-5).
7. Pull the rear panel away from the frame. Disconnect the ribbon cable from
its motherboard connector by pressing down and out on the connector locks.
8. Continue with the procedure which referred you to this one.
Assembly Replacement and Post-Repair Procedures
14-7
A1, A2 Front Panel Keyboard, Interface
How to Remove the Front Panel Keyboard or Interface
1. Perform the “Initial Front Panel Procedure.”
2. Slide the front panel over the type-N connectors.
CES)
13
(4
PLACES)
Figure 14-6. Location of Aland A2 components
14-8
Assembly Replacement and Post-Repair Procedures
3. Disconnect the ribbon cable from the front panel by pressing down and out
on the connector locks.
4. Remove the probe power cable (item 11) and the RPG cable (item 12).
5. Remove the four screws in the corners of the A2 assembly (item 13).
6. Insert the blade of a small flat screwdriver into the slots on the sides of the
ribbon cable connector (item 14). Gently pry upwards on either side of the
connector until it is loose.
7. Remove the remaining seven screws from the Al assembly (item 15).
Reverse Removal Procedure to Reinstall
After reinstallation, refer to “Post-Repair Procedures” at the end of this chapter
to ensure that the analyzer operates properly.
Assembly Replacement and Post-Repair Procedures
14-9
A3 Source
How to Remove the Source
1. Remove the power cord and the top cover (see “Cover Removal Procedure”).
2. Remove the two screws with washers (item 17, Figure 14-7) from the source
retainer bracket. Remove the bracket.
Figure 14-7. Location of Source Parts
3. Disconnect the semi-rigid cables (item 18) at the bulkhead connector and
source.
4. Pull the two retention clips (item 19) at the front and rear of the source
module to an upright position.
5. Push the disconnected cables toward the right side of the analyzer.
6. Pull up on the source bracket handle (item 20) and remove the source.
14-10
Assembly Replacement and Post-Repair Procedures
Reverse Removal Procedure to Reinstall
--
n
n
Keep the semi-rigid cables out of the way as you reinstall the source.
Make sure the edges of the sheet metal partition slide into the guides at the
front and back of the source compartment.
Make sure the source is well seated in the motherboard connector.
Remember to push down the retention clips.
After reinstallation, refer to “Post-Repair Procedures” at the end of this
chapter to ensure that the analyzer operates properly.
Assembly Replacement and Post-Repair Procedures
14-11
A15 Preregulator
How to Remove the Preregulator
1. Perform the “Initial Rear Panel Procedure.”
Figure 14-8. Location of Preregulator Fasteners and Wires
14-12
Assembly Replacement and Post-Repair Procedures
2. Remove the remaining four screws (item 22, Figure 14-8) in the rear frame:
two on the top and two on the bottom.
3. Disconnect the Al5 wire bundle (item 23) from the A8 post-regulator board
assembly.
4. Disconnect the Al5 wires (item 24) from the motherboard.
5. Pull the preregulator assembly free from the frame.
Reverse Removal Procedure to Reinstall
After reinstallation, refer to “Post-Repair Procedures” at the end of this chapter
to ensure that the analyzer operates properly.
Assembly Replacement and Post-Repair Procedures
14-13
A16 Rear Panel Board Assembly
How to Remove the Rear Panel
1. Perform the “Initial Rear Panel Procedure.”
Figure 14-9. Location of Rear Panel Fasteners
2. Remove the hex screws (item 26, Figure 14-9) from the HP-IB connector and
the test set interconnect connector.
3. Remove the hex nuts and lock washers (item 27) from the AUX INPUT, EXT
AM, and EXT TRIGGER BNC connectors.
4. Remove the rear panel board assembly.
14-14
Assembly Replacement and Post-Repair Procedures
Reverse Removal Procedure to Reinstall
Note
Torque the hex screws to 4 in-lb maximum.
After reinstallation, refer to “Post-Repair Procedures” at the end of this chapter
to ensure that the analyzer operates properly.
Assembly Replacement and Post-Repair Procedures
14-15
A18 Display
How to Remove the Display
1. Remove the power cord and the top cover (see “Cover Removal Procedure”).
Figure 14-10. Location of Display Fasteners and Parts
14-16
Assembly Replacement and Post-Repair Procedures
2. Remove the bezel’s softkey cover (item 29, Figure 14-10) by sliding your
fingernail under the left edge, near the top or bottom of the cover.
3. Pry the softkey cover away from the bezel. Take care to not scratch the
glass.
4. Remove the two screws (item 30) exposed by the previous step.
5. Remove the bezel (item 31) carefully; it is heavy for its size.
6. Remove the gasket from the front of the CRT.
7. At the A19 GSP assembly, disconnect the grey ribbon cable (item 32) from
the CRT.
8. Remove the four screws on the top of the display shield (item 33).
9. Start to slide the display out of the instrument by pushing on the back of the
display assembly. There is a hole at the rear of the display shielding where
you can reach in to push the display.
How to Reinstall the Display
1. Remove and set aside the bottom shield attached to the replacement display.
Install the bottom shield on the old display assembly before it is returned for
repair.
2. Leave the ribbon cable (A18W1) in the fastened position for easy retrieval
through the rear display shielding.
3. Reverse the first six steps.
After reinstallation, refer to “Post-Repair Procedures” at the end of this chapter
to ensure that the analyzer operates properly.
Assembly Replacement and Post-Repair Procedures
14-17
A30 Directional Coupler
How to Remove the Directional Coupler
1. Perform the “Initial Front Panel Procedure.”
REAR
BOTTOM
RIGHT
SIDE
Figure 14-11. Location of Coupler Screws on Bottom Front Frame
14-18
Assembly Replacement and Post-Repair Procedures
2. Remove the three screws which fasten the coupler to the bottom front
frame (item 35, Figure 14-11).
3. Remove the front panel by sliding it out and over the type-N connectors.
4. Disconnect the ribbon cable from the front panel by pressing down and out
on the connector locks.
5. Remove the trim strip (item 36, Figure 14-12) on the right side of the front
panel by prying under the strip with a flat screwdriver.
6. Remove the right side front handle (item 37).
Figure 14-12. Location of Directional Coupler Hardware
7. Remove the screw on the side edge of the frame (item 38).
8. Disconnect the semi-rigid cables from the coupler.
9. Remove the coupler and bracket from the analyzer.
10. Remove the screws (item 39) that fasten the bracket to the coupler.
11. Disconnect any remaining cables from the coupler.
Reverse Removal Procedure to Reinstall
After reinstallation, refer to “Post-Repair Procedures” at the end of this chapter
to ensure that the analyzer operates properly.
Assembly Replacement and Post-Repair Procedures
14-19
B1 Fan
How to Remove the Fan
1. Perform the “Initial Rear Panel Procedure.”
(4 PLACES)
Figure 14-13. Location of Fan Wire Bundle and Screws
2. Disconnect the fan’s wire bundle from its motherboard connector (item 40,
Figure 14-13).
3. Remove the Torx screws (item 41) from the four corners of the fan.
Reverse Removal Procedure to Reinstall
After reinstallation, refer to “Post-Repair Procedures” at the end of this chapter
to ensure that the analyzer operates properly.
14-20
Assembly Replacement and Post-Repair Procedures
A9BT1 Battery
How to Remove the Battery
1. Remove the A9 CPU board from its card cage slot.
2. Unsolder and remove the battery from the A9 CPU board.
Warning
Battery A9BT1 contains lithium. Do not incinerate or
puncture this battery. Dispose of the discharged battery in
a safe manner.
Replacing the Battery
1. Make sure the new battery is inserted into the A9 board with the correct
polarity.
2. Solder the battery into place.
3. Replace the A9 CPU board.
Assembly Replacement and Post-Repair Procedures
14-21
Post-Repair Procedures
After you repair or replace an assembly, check the following table. It lists any
additional service procedures that must be performed to ensure the instrument
is working properly.
Table 14-1. Post-Repair Procedures
Replaced or Repaired
Assembly
Adjustments
Correction Constants (CC)
Verification
A1 Front Panel
Keyboard
None
Internal Test 0
Internal Test 23
A2 Front Panel
Interface
None
Internal Test 0
Internal Test 23
Internal Test 12
A3 Source
A9 CC Jumper Position
Source Default CC (test 44)
Source Pretune Default CC (Test 45)
Analog Bus CC (Test 46)
RF Output Power (Test 47)
Source Pretune (Test 48)
Frequency Response CC (Tests 53 and 57)
Cavity Oscillator CC (Test 54)
Source Spur Avoidance Tracking
EEPROM Backup Disk
Reflection Test Port
Output Power Range
and Level Linearity
A4/A5/A6 Samplers
A9 CC Jumper Position
Frequency Response CC (Tests 53 and 57)
IF Amplifier CC (Test 51)
EEPROM Backup Disk
Test Port Crosstalk
A7 Pulse Generator
A9 CC Jumper Position
Frequency Response CC (Tests 53 and 57)
EEPROM Backup Disk
Reflection Test Port
Output Power Range
and Level Linearity
A8 Post Regulator
A9 CC Jumper Position
Source Spur Avoidance Tracking
Cavity Oscillator CC (Test 54)
EEPROM Backup Disk
Internal Test 0
Check A8 Test Point
Voltages
14-22
Assembly Replacement and Post-Repair Procedures
Table 14-1. Post-Repair Procedures (continued)
Replaced or Repaired
Assembly
Adjustments
Correction Constants (CC)
Verification
49 CPU
A9 CC Jumper Position
Model Number CC (750 only)
Display Intensity CC (Test 49)
Serial Number CC (Test 55)
Option Number CC (Test 56)
Source Default CC (Test 44)
Source Pretune Default CC (Test 45)
Analog Bus CC (Test 46)
RF Output Power CC (Test 47)
Source Pretune CC (Test 48)
Frequency response CC (Tests 53 and 57)
ADC Offset CC (Test 52)
IF Amplifier CC (Test 51)
Cavity Oscillator CC (Test 54)
EEPROM Backup Disk
Reflection Test Port
Output Power Range
and Level Linearity
Magnitude Dynamic Accuracy
Phase Dynamic Accuracy
Al0 Digital IF
A9 CC Jumper Position
Analog Bus CC (Test 46)
Frequency Response CC (Tests 53 and 57)
IF Amplifier CC (Test 51)
EEPROM Backup Disk
Transmission Test Port
Input Noise Floor
Test Port Crosstalk
System Trace Noise
All Phase Lock
A9 CC Jumper Position
Analog Bus CC (Test 46)
Pretune Default CC (Test 45)
Source Pretune CC (Test 45)
EEPROM Backup Disk
Reflection Test Port
Output Frequency Range
and Accuracy
Al2 Reference
High/Low Band Transition
Frequency Accuracy
Reflection Test Port
Output Frequency Range
and Accuracy
Al3 Frac-N (Analog)
Frac-N Spur Avoidance and FM
Sideband
Reflection Test Port
Output Frequency Range
and Accuracy
Al4 Frac-N (Digital)
Frac-N Frequency Range
Frac-N Spur Avoidance and FM Sideband
Reflection Test Port
Output Frequency Range
and Accuracy
Al5 Preregulator
None
Self Test
Al6 Rear Panel Board
None
Internal Test 13
Al7 Motherboard
None
Self Test
A18 Display
Vertical Position and Focus
Display Intensity CC (Test 49)
only if needed
Internal Tests 66 - 80
Assembly Replacement and Post-Repair Procedures
14-23
Table 14-1. Post-Repair Procedures (continued)
Replaced or Repaired
Assembly
Adjustments
Correction Constants (CC)
Verification
A19 Graphic System
Processor
None
Internal Tests 59 - 80
A30 Dual Directional
Coupler
A9 CC Jumper Position
Frequency Response CC (Tests 53 and 57)
RF Output Power CC (Test 47)
EEPROM Backup Disk
Verification
A3A5 Step Attenuator
A9 CC Jumper Position
RF Output Power CC (Test 47)
EEPROM Backup Disk
Reflection Test Port
Output Power Range
and Level Linearity
A3AT 14 dB Attenuator
A9 CC Jumper Position
RF Output Power CC (Test 47)
EEPROM Backup Disk
Reflection Test Port
Output Power Range
8 dB Attenuator
A9 CC Jumper Position
RF Output Power CC (Test 47)
EEPROM Backup Disk
Reflection Test Port
Output Power Range
14-24
Assembly Replacement and Post-Repair Procedures
15
Safety and Licensing
Notice
The information contained in this document is subject to change without notice.
Hewlett-Packard makes no warranty of any kind with regard to this material,
including but not limited to, the implied warranties of merchantability and
fitness for a particular purpose. Hewlett-Packard shall not be liable for errors
contained herein or for incidental or consequential damages in connection with
the furnishing, performance, or use of this material.
Certification
Hewlett-Packard Company certifies that this product met its published
specifications at the time of shipment from the factory. Hewlett-Packard
further certifies that its calibration measurements are traceable to the United
States National Institute of Standards and Technology, to the extent allowed
by the Institute’s calibration facility, and to the calibration facilities of other
International Standards Organization members.
Safety and Licensing
15-1
Warranty
This Hewlett-Packard instrument product is warranted against defects in
material and workmanship for a period of one year from date of shipment.
During the warranty period, Hewlett-Packard Company will, at its option, either
repair or replace products which prove to be defective.
For warranty service or repair, this product must be returned to a service
facility designated by Hewlett-Packard. Buyer shall prepay shipping charges to
Hewlett-Packard and Hewlett-Packard shall pay shipping charges to return the
product to Buyer. However, Buyer shall pay all shipping charges, duties, and
taxes for products returned to Hewlett-Packard from another country.
Hewlett-Packard warrants that its software and firmware designated by
Hewlett-Packard for use with an instrument will execute its programming
instructions when properly installed on that instrument. Hewlett-Packard does
not warrant that the operation of the instrument, or software, or firmware will
be uninterrupted or error-free.
L IMITATION
OF
W ARRANTY
The foregoing warranty shall not apply to defects resulting from improper or
inadequate maintenance by Buyer, Buyer-supplied software or interfacing,
unauthorized modification or misuse, operation outside of the environmental
specifications for the product, or improper site preparation or maintenance.
NO OTHER WARRANTY IS EXPRESSED OR IMPLIED. HEWLETT-PACKARD
SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
E XCLUSIVE R EMEDIES
THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE
REMEDIES. HEWLETT-PACKARD SHALL NOT BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.
Assistance
Product maintenance agreements and other customer assistance agreements are
available for Hewlett-Packard products.
For any assistance, contact your nearest Hewlett-Packard Sales and Service
Office.
15-2
Safety and Licensing
Hewlett-Packard Sales and Service Offices
US FIELD OPERATIONS
Headquarters
Hewlett-Packard Co.
19320 Pruneridge Avenue
Cupertino, CA 95014
(800) 752-0900
California, Northern
Hewlett-Packard Co.
301 E. Evelyn
Mountain View, CA 94041
(415) 694-2000
California, Southern
Hewlett-Packard Co.
1421 South Manhattan Ave.
Fullerton, CA 92631
(714) 999-6700
Colorado
Hewlett-Packard Co.
24 Inverness Place, East
Englewood, CO 80112
(303) 649-5512
Atlanta Annex
Hewlett-Packard Co.
2124 Barrett Park Drive
Kennesaw, GA 30144
(404) 648-0000
Illinois
Hewlett-Packard Co.
545 E. Algonquin Rd.
Arlington Heights, IL 60005
(847) 342-2000
New Jersey
Hewlett-Packard Co.
150 Green Pond Rd.
Rockaway, NJ 07866
(201) 586-5400
Texas
Hewlett-Packard Co.
930 E. Campbell Rd.
Richardson, TX 75081
(214) 231-6101
EUROPEAN FIELD OPERATIONS
Headquarters
Hewlett-Packard S.A.
150, Route du Nant-d'Avril
1217 Meyrin 2/Geneva
Switzerland
(41 22) 780.8111
France
Hewlett-Packard France
1 Avenue Du Canada
Zone D'Activite De Courtaboeuf
F-91947 Les Ulis Cedex
France
(33 1) 69 82 60 60
Germany
Hewlett-Packard GmbH
Hewlett-Packard Strasse
61352 Bad Homburg v.d.H
Germany
(49 6172) 16-0
Great Britain
Hewlett-Packard Ltd.
Eskdale Road, Winnersh Triangle
Wokingham, Berkshire RG41 5DZ
England
(44 734) 696622
Safety and Licensing
15-3
Hewlett-Packard Sales and Service Offices (continued)
INTERCON FIELD OPERATIONS
Headquarters
Hewlett-Packard Company
3495 Deer Creek Road
Palo Alto, California, USA
94304-1316
(415) 857-5027
Australia
Canada
Hewlett-Packard Australia Ltd. Hewlett-Packard (Canada) Ltd.
31-41 Joseph Street
17500 South Service Road
Blackburn, Victoria 3130
Tram-Canada Highway
(61 3) 895-2895
Kirkland, Quebec H9J 2X8
Canada
(514) 697-4232
China
China Hewlett-Packard Company
38 Bei San Huan X1 Road
Shuang Yu Shu
Hai Dian District
Beijing, Chlna
(86 1) 256-6888
Japan
Hewlett-Packard Japan, Ltd.
9-l Takakura-Cho, Hachloji
Tokyo 192, Japan
(81 426) 60-2111
Singapore
Hewlett-Packard Singapore (Pte.) Ltd.
150 Beach Road
#29-00 Gateway West
Singapore 0718
(65) 291-9088
Taiwan
Hewlett-Packard Taiwan
8th Floor, H-P Building
337 Fu Hsing North Road
Taipei, Taiwan
(886 2) 712-0404
Shipment for Service
If you are sending the instrument to Hewlett-Packard for service, ship the
analyzer to the nearest HP service center for repair, including a description of
any failed test and any error message. Ship the analyzer, using the original or
comparable anti-static packaging materials. A listing of Hewlett-Packard sales
and service offices is provided in this chapter.
15-4
Safety and Licensing
Safety Symbols
The following safety symbols are used throughout this manual. Familiarize
yourself with each of the symbols and its meaning before operating this
instrument.
Caution
Caution denotes a hazard. It calls attention to a procedure
that, if not correctly performed or adhered to, would result in
damage to or destruction of the instrument. Do not proceed
beyond a caution note until the indicated conditions are fully
understood and met.
Warning
Warning denotes a hazard. It calls attention to a procedure
which, if not correctly performed or adhered to, could
result in injury or loss of life. Do not proceed beyond
a warning note until the indicated conditions are fully
understood and met.
Safety and Licensing
15-5
Instrument Markings
The instruction documentation symbol. The product is marked with
this symbol when it is necessary for the user to refer to the instructions in the
documentation.
“CE” The CE mark is a registered trademark of the European Community. (If
accompanied by a year, it is when the design was proven.)
“ISM1-A” This is a symbol of an Industrial Scientific and Medical Group 1 Class
A product.
“CSA” The CSA mark is a registered trademark of the Canadian Standards
Association.
15-6
Safety and Licensing
General Safety Considerations
Safety Earth Ground
Warning
This is a Safety Class I product (provided with a protective
earthing ground incorporated in the power cord). The mains
plug shall only be inserted in a socket outlet provided
with a protective earth contact. Any interruption of the
protective conductor, inside or outside the instrument,
is likely to make the instrument dangerous. Intentional
interruption is prohibited.
Before Applying Power
Caution
Make sure that the analyzer line voltage selector switch is set to
the voltage of the power supply and the correct fuse is installed.
Caution
If this product is to be energized via an autotransformer make
sure the common terminal is connected to the neutral (grounded
side of the mains supply).
Servicing
Warning
No operator serviceable parts inside. Refer servicing to
qualifled personnel. To prevent electrical shock, do not
remove covers.
Warning
These servicing instructions are for use by qualifled
personnel only. To avoid electrical shock, do not perform
any servicing unless you are qualified to do so.
Warning
The opening of covers or removal of parts is likely to
expose dangerous voltages. Disconnect the instrument from
all voltage sources while it is being opened.
Safety and Licensing
15-7
Warning
Adjustments described in this document may be performed
with power supplied to the product while protective covers
are removed. Energy available at many points may, if
contacted, result in personal injury.
Warning
The detachable power cord is the instrument disconnecting
device. It disconnects the mains circuits from the main
supply before other parts of the instrument. The front
panel switch is only a standby switch and is not a LINE
switch.
Warning
The power cord is connected to internal capacitors that may
remain live for 10 seconds after disconnecting the plug from
its power supply.
Warning
The analyzer’s internal battery contains lithium. Do
not incinerate or puncture this battery. Dispose of the
discharged battery in a safe manner.
Warning
For continued protection against fire hazard replace line
fuse only with same type and rating (F 5A/250V). The use of
other fuses or material is prohibited.
15-8
Safety and Licensing
Index
1
10 0 kHz pulses, 7-16
10 MHz HI OUT Waveform from
A14J1, 7-27
1st LO signal at sampler/mixer, 8-12
2
25 MHz HI OUT Waveform from
A14J1, 7-27
2nd IF (4 kHz) signal locations, 8-12
2nd LO locations, 8-13
2ND LO waveforms, 7-21
4
4 kHz signal check, 8- 11
4 MHz reference signal, 7-20
4 MHz REF signal check, 8-8
5
+ 5V digital supply
theory of operation, 12-7
6
60 MHz HI OUT Waveform from
A14J1, 7-27
8
8752C
theory of operation, 12-1
A
A10 assembly signals required, 8-9
A10 check by substitution or signal
examination, 8-8
A10 digital IF, 12-29
digital control, 12-11
A10 Digital IF, 10-36
A1l input signals, 7-37
A1l Input Signals, 7-38
A1l phase lock,
10 - 37
source, 12-15
A1l phase lock and A3 source check,
7-8
A1l phase lock check, 7-37
Al2 digital control signals check,
7-23
Al2 reference, 10-44
source, 12-14
Al2 reference check, 7-13
A13/A14 Fractional-N Check, 7-24
Al3 frac-N analog
source, 12-14
Al4 Divide-by-N Circuit Check, 7-29
Al4 frac-N digital
source, 12-14
Al4 fractional-N (digital), 10-47
Al4 generated digital control signals,
7-31
A14-to-A13 digital control signals
check, 7-30
Al4 VCO exercise, 7-28
Al5 preregulator
Index-1
removal, 14-12
theory of operation, 12-6
Al5 preregulator check, 5-9
A15W1 plug detail, 5-10
Al6 rear panel
digital control, 12-13
Al6 rear panel board
removal, 14-14
Al8 display
digital control, 12-12
power, 12-9
removal, 14-16
Al8 display operation check, 6-7
Al8 power supply voltages, 6-13
A19 graphics system processor
digital control, 12-12
A19 GSP
digital control, 12-12
A19 GSP and Al8 display operation
check, 6-7
A19 power supply voltages for display,
6-13
A19 walking one pattern, 6-16
Al/A2 front panel troubleshooting,
6-7
Al front panel keyboard
digital control, 12-10
removal, 14-8
A2 front panel interface
removal, 14-8
A2 front panel processor
digital control, 12-11
A30 directional coupler
removal, 14-18
A30 dual directional coupler, 12-23
A3 source
high band theory, 12-19
low band theory, 12-16
removal, 14-10
source, 12-15
theory of operation, 12-3, 12-14
Index-2
A3 source and All phase lock check,
7-8
A4 R sampler/mixer, 12-28
A4 sampler/mixer check, 7-6
A5 A sampler/mixer, 12-28
A6 B sampler/mixer, 12-28
A7 pulse generator
source, 12-14
A7 pulse generator check, 7-33
A8 fuses and voltages, 5-14
A8 post regulator
air flow detector, 12-8
display power, 12-9
green LEDs, 12-8
probe power, 12-9
shutdown circuit, 12-8
theory of operation, 12-8
variable fan circuit, 12-8
A8 post regulator test points, 5-5
A9BT1 battery
removal, 14-2 1
A9 CC jumper position adjustment,
3-5
A9 CC jumper positions, 10-8
A9 CPU
digital control, 12-l 1
A9 CPU operation check, 6-4
ABUS Cor., 10-14
ABUS Test., 10-l 1
accessories
part numbers, 13-38
accessories inspection, 9-3
accessories troubleshooting chapter,
9-1
adapters, 1-3
ADC Hist., 10-12
ADC Lin., 10-10
ADC main, 10-25
ADC offset correction constants (test
#52) adjustment, 3-2 1
ADC Ofs., 10-10
ADC Ofs Cor., 10-14
ADD, 10-6
addresses for HP-IB systems, 4-7
adjustment
A9 CC jumper position, 3-5
ADC offset correction constants
(test #52), 3-21
analog bus correction constants
(Test #46), 3-10
analyzer top cover removal, 3-4
cavity oscillator frequency
correction constants (test #54),
3-24
display degaussing (demagnetizing),
3-45
display intensity adjustments (test
#49), 3-15
EEPROM backup disk procedure,
3-38
error messages, 3-l
fractional-N frequency range, 3-46
fractional-N spur avoidance and
FM sideband, 3-54
frequency accuracy, 3-49
frequency response correction
constants (test s #53 and #57),
3-22
high/low band transition, 3-51
IF amplifier correction constants
(test #51), 3-19
initialize EEPROMs (test 58), 3-37
model number correction constant
(option 075 only), 3-42
option numbers correction constant
(test #56), 3-34
order of performance, 3-2
RF output power correction
constants (tes t #47), 3-11
serial number correction constant
(test #55), 3-32
source default correction constants
(test #44), 3-8
source pretune correction constants
(test #48), 3-14
source pretune default correction
constants (tes t #45), 3-9
source spur avoidance tracking,
3-58
test equipment specifications, 3-3
vertical position and focus, 3-43
when to perform, 3-l
adjustments
test equipment specifications, 1-1
adjustment tests, 10-3
Adjustment Tests, 10-14
ADJUSTMENT TESTS, 10-5
air flow detector, 12-8
ALC ON OFF, 10-20
ALL INT, 10-7
analog bus, 10-25
ANALOG BUS, 10-28
analog bus check of reference
frequencies, 7-13
analog bus checks YO coil drive, 7-11
analog bus codes, 10-53
analog bus correction constants (Test
#46) adjustment, 3- 10
analog bus node 1, 10-30
analog bus node 11, 10-37
analog bus node 12, 10-37
analog bus node 13,14, 10-38
analog bus node 15, 10-39
analog bus node 16, 10-40
analog bus node 17, 10-41
analog bus node 18, 10-42
analog bus node 19, 10-43
analog bus node 2, 10-31
analog bus node 20, 10-43
analog bus node 21, 10-44
analog bus node 23, 10-45
analog bus node 24, 10-46
Index-3
analog bus node 27, 10-47
analog bus node 29, 10-48
analog bus node 3, 10-32
analog bus node 30, 10-49
analog bus node 4, 10-33
analog bus node 5, 10-34
analog bus node 6, 10-34
analog bus node 7, 10-35
analog bus node 8, 10-35
analog bus node 9, 10-36
analog bus nodes, 10-29
A3, 10-29
ANALOG BUS ON OFF, 10-24
analog in menu, 10-27
analog node 10, 10-36
analyzer
theory of operations, 12-1
analyzer block diagram, 4-16
analyzer HP-IB address, 4-7
analyzer options available, l-7
analyzer (spectrum), 1-3
antistatic wrist strap, 1-3
appendix for source group
troubleshooting, 7-39
assemblies
part numbers, 13-6
rebuilt-exchange, 13-2
assembly replacement, 14-1
Al5 preregulator, 14-12
Al6 rear panel board, 14-14
A18 display, 14-16
Al front panel keyboard, 14-8
A2 front panel interface, 14-8
A30 directional coupler, 14-18
A3 source, 14-10
A9BT1 battery, 14-21
Bl fan, 14-20
covers, 14-3
front panel, 14-4
rear panel, 14-6
tools, 14-2
Index-4
assembly replacement sequence, 4-2
assistance, 15-2
attenuator
theory of operation, 12-3
attenuators (fixed), 1-3
attenuator (step), 1-3
AUX OUT ON OFF, 10-27
available options, l-7
B
B1 fan
removal, 14-20
bad cables, 9-l
battery
removal, 14-2 1
BATTERY FAILED. STATE MEMORY
CLEARED, 10-54
BATTERY LOW! STORE SAVE REGS
TO DISK, 10-54
block diagram, 4-16
digital control group, 6-3
power supply, 5-24
power supply functional group,
5-3
broadband power problems, 7-40
built-in test set, 12-23
bulk tape eraser or demagnetizer,
1-3
bus
analog, 10-25
bus nodes, 10-29
C
cable inspection, 6-10
cables, l-3
part numbers, 13-12, 13-14, 13-16,
13-18-25
cable test, 9-5
CAL FACTOR SENSOR A, 10-6
CAL FACTOR SENSOR B, 10-6
CALIBRATION ABORTED, 10-54
calibration coefficients, 11-1
calibration device inspection, 9-3
calibration kit 7 mm, 50 ohm, l-3
calibration kit device verification,
9-4
calibration kit type-N, 759, l-3
calibration procedure, 11-4, 11-6
CALIBRATION REQUIRED, 10-55
care of connectors, l-5
CAUTION: OVERLOAD ON REFL PORT,
POWER REDUCED, 8-2
CAUTION: OVERLOAD ON TRANS
PORT, POWER REDUCED, 8-2
cavity oscillator frequency correction
constants (test #54) adjustment,
3-24
Cav Osc Cor., 10-14
CC procedures
initialize EEPROMs (test 58), 3-37
center conductor damage, 9-3
certification, 15-1
characteristics
type-N test port (50 ohm), 2-6
type-N test port (500) directivity,
2-6
type-N test port (500) load match,
2-7
type-N test port (50 ohm) reflection
tracking, 2-6
type-N test port (500) source match
(reflection), 2-6
type-N test port (500) source match
(transmission), 2-6
type-N test port (500) transmission
tracking, 2-7
type-N test port (75 ohm), 2-7
type-N test port (75 ohm) directivity,
2-7
type-N test port (75 ohm) load match,
2-8
type-N test port (75 ohm) reflection
tracking, 2-8
type-N test port (75 ohm) source match
(reflection), 2-7
type-N test port (75 ohm) source match
(transmission), 2-8
type-N test port (75 ohm) transmission
tracking, 2-8
chassis
part numbers, 13-28
check
1st LO signal at sampler/mixer,
8-12
4 MHz REF signal, 8-8
A10 by substitution or signal
examination, 8-8
A11 phase lock, 7-37
Al2 digital control signals, 7-23
Al2 reference, 7-13
A13/A14 Fractional-N, 7-24
Al4 Divide-by-N Circuit Check,
7-29
A14-to-A13 digital control signals,
7-30
Al5 Preregulator, 5-9
A19 GSP and Al8 display operation,
6-7
Al/A2 front panel, 6-7
A3 source and All phase lock, 7-8
A4 sampler/mixer, 7-6
A7 pulse generator, 7-33
A8 fuses and voltages, 5-14
A9 CPU control, 6-4
CPU control, 6-4
digital control, 4- 12
disk drive, 4-8
fan voltages, 5-22
FN LO at A12, 7-19
for a faulty assembly, 5-11
GSP and Al8 display operation,
6-7
Index-5
HP-IB systems, 4-7
line voltage, selector switch, fuse,
5-7
motherboard, 5-13
operating temperature, 5-13
operation of A19 GSP and Al8
display, 6-7
operation of A9 CPU, 6-4
phase lock error message, 7-4
plotter or printer, 4-8
post regulator voltages, 5-5
power supply, 4-11
power supply voltages for display,
6-13
power up sequence, 4-12
preregulator LEDs, 4-11
R, A, and B inputs, 8-4
rear panel LEDs, 4-11
the 4 kHz signal, 8-11
YO coil drive with analog bus, 7-11
check front panel cables, 6-10
cleaning of connectors, l-5
CLEAR LIST, 10-6
CMOS RAM, 10-7
coax cable, 1-3
codes for analog bus, 10-53
coefficients, 11-1
comb tooth at 3 GHz, 7-34
components related to specific error
terms, 9-3
connection techniques, 1-5
connector
care of, 1-5
CONTINUE TEST, 10-5
controller HP-IB address, 4-7
controller troubleshooting, 4-9
conventions for symbols, 10-52
correction constants, 3-l
initialize EEPROMs (test 58), 3-37
CORRECTION CONSTANTS NOT
STORED, 10-55
Index-6
CORRECTION TURNED OFF, 10-55
counter, 10-25
COUNTER
OFF, 10-27
counter (frequency), 1-3
counter readout location, 10-41
cover removal, 14-3
CPU
digital control, 12-11
CPU operation check, 6-4
C P U walking one pattern, 6-16
CRT demagnetizer or bulk tape eraser,
1-3
CURRENT PARAMETER NOT IN CAL
SET, 10-55
customer assistance, 15-2
D
damage to center conductors, 9-3
DEADLOCK, 10-55
DELETE, 10-6
demagnetizer or bulk tape eraser,
l-3
description of tests, 10-7
DEVICE
not on, not connect, wrong addrs,
10-56
diagnose softkey, 10-7
diagnostic
error terms, 11-2
diagnostic LEDs for A15, 5-4
diagnostic routines for phase lock,
7-40
diagnostics
internal, 10-2
diagnostics of analyzer, 4-3
diagnostic tests, 6-11
diagram
A4 sampler/mixer to phase lock
cable, 7-7
digital control group, 6-3
diagram of HP 8752C, 4-16
diagram of power supply, 5-24
DIF Control, 10-9
DIF Counter, 10-9
digital control
Al0 digital IF, 12-11
Al6 rear panel, 12-13
A18 display, 12-12
A19 graphics system processor,
12-12
A19 GSP, 12-12
Al front panel keyboard, 12-10
A2 front panel processor, 12-11
A9 CPU, 12-11
digital signal processor, 12-12
EEPROM, 12-12
main CPU, 12-11
main RAM, 12-11
theory of operation, 12-9
digital control block diagram, 6-3
digital control check, 4-12
digital control lines observed using
L INTCOP as trigger, 8-10
digital control signals A14-to-A13
check, 7-30
digital control signals check, 7-23
digital control signals generated from
A14, 7-31
digital control troubleshooting
chapter, 6-l
digital data lines observed using L
INTCOP as trigger, 8-10
digital IF, 10-36, 12-29
digital control, 12-11
digital voltmeter, 1-3
directional coupler
removal, 14-18
directivity characteristics
type-N test port (50 ohm), 2-6
type-N test port (75 ohm), 2-7
directivity (ED), 11-11
disable shutdown circuitry, 5-16
DISK
not on, not connected, wrong addrs,
10-56
disk drive check, 4-8
disk drive (external) HP-IB address,
4-7
disk (floppy), l-3
DISK HARDWARE PROBLEM, 10-56
DISK MESSAGE LENGTH ERROR,
10-56
DISK READ/WRITE ERROR, 10-57
Disp 2 Ex., 10-14
Disp/cpu corn., 10-16
display
digital control, 12-12
power, 12-9
removal, 14-16
display bezel
part numbers, 13-26
display degaussing (demagnetizing),
3-45
display intensity adjustments (test
#49), 3-15
display operation check, 6-7
display power supply on A19, 6-13
display tests, 10-3, 10-16
DISPLAY TESTS, 10-5
DIV FRAC N, 10-28
Divide-by-N Circuit Check, 7-29
DONE, 10-6
DRAM cell, 10-16
DSP ALU, 10-9
DSP Control, 10-10
DSP Intrpt, 10-9
DSP RAM, 10-0
DSP Wr/Rd, 10-9
dual directional coupler, 12-23
Index-7
E
earth ground wire and static-control
table mat, 1-3
EDIT, 10-6
edit list menu, 10-6
EEPROM backup disk procedure,
3-38
equipment
A9 CC jumper position adjustment,
3-5
ADC offset correction constants
adjustment, 3-21
analog bus correction constants
adjustment, 3-10
cavity oscillator frequency
correction constants
adjustment, 3-24
display degaussing, 3-45
display intensity adjustment, 3-15
EEPROM backup disk procedure,
3-38
fractional-N frequency range
adjustment, 3-46
fractional-N spur avoidance and
FM sideband adjustment, 3-54
frequency accuracy adjustment,
3-49
frequency response correction
constants adjustment, 3-22
high/low band transition
adjustment, 3-51
IF amplifier correction constants
adjustment, 3-19
model number correction constant
adjustment (option 075 only),
3-42
option numbers correction constant
adjustment, 3-34
RF output power correction
constants adjustment, 3-11
Index-8
serial number correction constant
adjustment, 3-32
source default correction constants
adjustment, 3-8
source pretune correction constants
adjustment, 3-14
source pretune default correction
constants adjustment, 3-9
source spur avoidance tracking
adjustment, 3-58
vertical position and focus
adjustments, 3-43
equipment for service, 1-1
error
BATTERY FAILED. STATE MEMORY
CLEARED, 10-54
BATTERY LOW! STORE SAVE REGS
TO DISK, 10-54
CALIBRATION ABORTED, 10-54
CALIBRATION REQUIRED, 10-55
CORRECTION CONSTANTS NOT
STORED, 10-55
CORRECTION TURNED OFF, 10-55
CURRENT PARAMETER NOT IN
CAL SET, 10-55
DEADLOCK, 10-55
DEVICE: not on, not connect,
wrong addrs, 10-56
DISK HARDWARE PROBLEM,
10-56
DISK MESSAGE LENGTH ERROR,
10-56
DISK: not on, not connected, wrong
addrs, 10-56
DISK READ/WRITE ERROR, 10-57
INITIALIZATION FAILED, 10-57
NO CALIBRATION CURRENTLY IN
PROGRESS, 10-57
NO IF FOUND: CHECK R INPUT
LEVEL, 10-58
NO PHASE LOCK: CHECK R INPUT
LEVEL, 10-58
NO SPACE FOR NEW CAL. CLEAR
REGISTERS, 10-58
NOT ENOUGH SPACE ON DISK
FOR STORE, IO-57
OVERLOAD ON INPUT R, POWER
REDUCED, 10-59
OVERLOAD ON REFL PORT,
POWER REDUCED, 10-58
OVERLOAD ON TRANS PORT,
POWER REDUCED, 10-59
PHASE LOCK CAL FAILED, 10-59
PHASE LOCK LOST, 10-60
POSSIBLE FALSE LOCK, 10-60
POWER SUPPLY HOT!, 10-61
POWER SUPPLY SHUT DOWN!,
10-61
POWER UNLEVELED, 10-60
POW MET INVALID, 10-60
POW MET: not on, not connected,
wrong addrs, 10-61
POW MET NOT SETTLED, 10-60
PRINTER: not on, not connected,
wrong addrs, 10-61
PROBE POWER SHUT DOWN!,
10-62
SAVE FAILED. INSUFFICIENT
MEMORY, 10-62
SELF TEST #n FAILED, 10-62
SOURCE POWER TRIPPED, RESET
UNDER POWER MENU, 10-62
SWEEP MODE CHANGED TO CW
TIME SWEEP, 10-63
SYSTEM IS NOT IN REMOTE, 10-63
TEST ABORTED, 10-63
TROUBLE! CHECK SETUP AND
START OVER, 10-63
WRONG DISK FORMAT, INITIALIZE
DISK, 10-63
error-correction procedure, 11-4
error message for phase lock, 7-4
error messages, 10-1, 10-54
during adjustments, 3-1
error messages for receiver failure,
8-2
error term inspection, 9-3
error terms, 11-1
directivity (ED), 11-11
isolation (crosstalk, Ex), 11-17
reflection tracking (ER), 11-15
source match (Es), 11-13
transmission tracking (ET), 11-19
E-terms, 11-1
external tests, 10-3, 10-12
EXTERNAL TESTS, 10-4
F
failure
All phase lock and A3 source
check, 7-8
A19 GSP and Al8 display operation,
6-7
A1/A2 front panel, 6-7
key stuck, 6-8
of self test, 4-3
phase lock error, 7-4
receiver, 8-2
RF power from source, 7-3
failures
HP-IB, 6-18
fan
air flow detector, 12-8
removal, 14-20
variable fan circuit, 12-8
fan speeds, 5-22
fan troubleshooting, 5-22
fan voltages, 5-22
faulty analyzer repair, 4-2
faulty cables, 9-l
faulty calibration devices or
connectors, 9-l
index-9
faulty group isolation, 4-10
filter (low pass), 1-3
firmware revision softkey, 10-51
floppy disk, 1-3
FM Coil - plot with 3 point sweep,
7-38
FM sideband and spur avoidance
adjustment, 3-54
FN Count., 10-11
FN LO at Al2 check, 7-19
FN LO waveform at A12J1, 7-19
FRAC N, 10-28
frac-N analog
source, 12-14
Frac N Cont., 10-10
frac-N digital
source, 12-14
FRACN TUNE mode HI OUT signal,
7-35
FRACN TUNE ON OFF, 10-20
Fractional-N Check, 7-24
fractional-N (digital), 10-47
fractional-N frequency range
adjustment, 3-46
fractional-N spur avoidance and FM
sideband adjustment, 3-54
frequency accuracy adjustment, 3-49
frequency counter, 1-3, 10-25
frequency output in SRC tune mode,
7-8
frequency response correction
constants (tests #53 and #57)
adjustment, 3-22
front panel
part numbers, 13-8
front panel cables, 13-14
front panel hardware, 13-14
front panel interface
removal, 14-8
front panel keyboard
digital control, 12-10
Index-10
removal, 14-8
front panel key codes, 6-8
front panel probe power voltages,
5-19
front panel processor
digital control, 12-11
front panel removal, 14-4
front panel troubleshooting, 6-7
Fr Pan Diag., 10-12
Fr Pan Wr/Rd, 10-10
functional group fault location, 4-10
functional groups
theory of operation, 12-5
fuse check, 5-7
G
graphics system processor
digital control, 12-12
green LED on Al5
power supply shutdown, 12-7
green LEDs on A8, 12-8
GSP
digital control, 12-12
GSP operation check, 6-7
H
hardkeys, 10-2
hardware
part numbers, 13-14, 13-16, 13-30,
13-32, 13-34, 13-35, 13-36
HB FLTR SW ON OFF, 10-21
Hewlett-Packard servicing, 4-2
high band REF signal, 7-17
high/low band transition adjustment,
3-51
high quality comb tooth at 3 GHz,
7-34
HI OUT signal in FRACN TUNE mode,
7-35
H MB line, 7-32
how to
adjust A9 CC jumper position, 3-5
adjust ADC offset correction
constants, 3-21
adjust analog bus correction
constants, 3-10
adjust cavity oscillator frequency
correction constants, 3-24
adjust display intensity, 3-15
adjust fractional-N spur avoidance
and FM sideband, 3-54
adjust frequency accuracy, 3-49
adjust frequency response
correction constants, 3-22
adjust high/low band transition,
3-51
adjust IF amplifier correction
constants, 3-19
adjust model number correction
constant (option 075 only),
3-42
adjust option numbers correction
constant, 3-34
adjust RF output power correction
constants, 3-11
adjust serial number correction
constant, 3-32
adjust source default correction
constants, 3-8
adjust source pretune correction
constants, 3- 14
adjust source pretune default
correction constants, 3-9
adjust source spur avoidance
tracking, 3-58
adjust the fractional-N frequency
range, 3-46
adjust vertical position and focus,
3-43
backup the EEPROM to disk, 3-38
clean connectors, l-5
degauss (demagnitize) the display,
3-45
identify the faulty functional group,
4-10
initialize EEPROMs, 3-37
ship analyzer for service, 15-4
troubleshoot accessories, 9-l
troubleshoot broadband power
problems, 7-40
troubleshoot digital control group,
6-l
troubleshoot receiver, 8-l
troubleshoot source group, 7-l
HP 8752C block diagram, 4-16
HP-IB addresses, 4-7
HP-IB cable, l-3
HP-IB Failures, 6-18
HP-IB mnemonic for service, 10-l
HP-IB service mnemonic definitions,
10-52
HP-IB system check, 4-7
IF amplifier correction constants (test
#51) adjustment, 3-19
IF GAIN AUTO, 10-23
IF GAIN OFF, 10-23
IF GAIN ON, 10-23
IF Step Cor., 10-14
improper calibration technique, 9-1
Init EEPROM, 10-15
INITIALIZATION FAILED, 10-57
initialize EEPROMs, 3-37
initial observations, 4-3
inputs check (R, A and B), 8-4
inspect cables, 6-10
inspect error terms, 9-3
inspection of test port connectors
and calibration devices, 9-3
inspect the accessories, 9-3
Inten DAC., 10-16
Index-11
Intensity Cor., 10-14
internal diagnostics, 10-2
internal diagnostic tests, 6-11
internal tests, 10-3, 10-7
INTERNAL TESTS, 10-4
invoking tests remotely, 10-52
isolation calibration procedure, 11-6
isolation (crosstalk, Ex), 11-17
J
jumper position, 10-8
K
key codes, 6-8
key failure identification, 6-8
keys in service menu, 10-1
kits
calibration kit 7 mm, 50 ohm, l-3
calibration kit type-N, 75 ohm, 1-3
tool, 1-3
verification kit 7 mm, l-3
L
labels
part numbers, 13-37
L ENREF line, 7-23
L HB and L LB Lines, 7-24
licensing, 15-1
light occluder, l-3
LIMITS NORM/SPCL, 10-5
line fuse check, 5-7
line power module
theory of operation, 12-7
line voltage check, 5-7
L INTCOP as trigger to observe control
lines, 8-10
L INTCOP as trigger to observe data
lines, 8-10
L LB and L HB Lines, 7-24
LO (2ND) waveforms, 7-21
load device verification, 9-4
Index-12
load match characteristics
type-N test port (50 ohm), 2-7
type-N test port (75 ohm), 2-8
location
diagnostic LEDs for A15, 5-4
post regulator test points, 5-5
power supply cable, 5-8
lock error, 7-4
LO OUT waveform at A14J2, 7-28
LOSS/SENSR LISTS, 10-5
low band REF signal, 7-18
low pass filter, 1-3
M
main ADC, 10-25
Main DRAM, 10-7
MAIN PWR DAC, 10-21
Main VRAM, 10-16
major assemblies
part numbers, 13-6
rebuilt-exchange, 13-2
measurement calibration coefficients,
11-1
measurement calibration procedure,
11-4, 11-6
measurement uncertainty, 2-4
window, 2-4
measuring receiver, l-3
menu
analog in, 10-27
edit list, 10-6
peek/poke, 10-50
service keys, 10-19
service modes, 10-23
test options, 10-5
tests, 10-3
menus for service, 10-l
message
BATTERY FAILED. STATE MEMORY
CLEARED, 10-54
BATTERY LOW! STORE SAVE REGS
TO DISK, 10-54
CALIBRATION ABORTED, 10-54
CALIBRATION REQUIRED, 10-55
CORRECTION CONSTANTS NOT
STORED, 10-55
CORRECTION TURNED OFF, 10-55
CURRENT PARAMETER NOT IN
CAL SET, 10-55
DEADLOCK, 10-55
DEVICE: not on, not connect,
wrong addrs, 10-56
DISK HARDWARE PROBLEM,
10-56
DISK MESSAGE LENGTH ERROR,
10-56
DISK: not on, not connected, wrong
addrs, 10-56
DISK READ/WRITE ERROR, 10-57
error, 10-54
INITIALIZATION FAILED, 10-57
NO CALIBRATION CURRENTLY IN
PROGRESS, 10-57
NO IF FOUND: CHECK R INPUT
LEVEL, 10-58
NO PHASE LOCK: CHECK R INPUT
LEVEL, 10-58
NO SPACE FOR NEW CAL. CLEAR
REGISTERS, 10-58
NOT ENOUGH SPACE ON DISK
FOR STORE, 10-57
OVERLOAD ON INPUT R, POWER
REDUCED, 10-59
OVERLOAD ON REFL PORT,
POWER REDUCED, 10-58
OVERLOAD ON TRANS PORT,
POWER REDUCED, 10-59
PHASE LOCK CAL FAILED, 10-59
PHASE LOCK LOST, 10-60
POSSIBLE FALSE LOCK, 10-60
POWER SUPPLY HOT!, 10-61
POWER SUPPLY SHUT DOWN!,
10-61
POWER UNLEVELED, 10-60
POW MET INVALID, 10-60
POW MET: not on, not connected,
wrong addrs, 10-61
POW MET NOT SETTLED, 10-60
PRINTER: not on, not connected,
wrong addrs, 10-61
PROBE POWER SHUT DOWN!,
10-62
SAVE FAILED. INSUFFICIENT
MEMORY, 10-62
SELF TEST #n FAILED, 10-62
SOURCE POWER TRIPPED, RESET
UNDER POWER MENU, 10-62
SWEEP MODE CHANGED TO CW
TIME SWEEP, 10-63
SYSTEM IS NOT IN REMOTE, 10-63
TEST ABORTED, 10-63
TROUBLE! CHECK SETUP AND
START OVER, IO-63
WRONG DISK FORMAT, INITIALIZE
DISK, 10-63
message for phase lock error, 7-4
messages
error, 10-1
meter (power), 1-3
microprocessor
theory of operation, 12-4
microwave connector care, l-5
minimum loss pad, l-3
miscellaneous
part numbers, 13-38
mnemonic definitions, 10-52
mnemonics for service keys, 10-l
model number correction constant
adjustment(option 075 only),
3-42
motherboard check, 5-13
Index-13
N
NO CALIBRATION CURRENTLY IN
PROGRESS, 10-57
nodes for analog bus, 10-29
NO FILE(S) FOUND ON DISK, 10-57
NO IF FOUND
CHECK R INPUT LEVEL, 7-4, 7-39,
10-58
NO PHASE LOCK
CHECK R INPUT LEVEL, 7-4, 7-39,
10-58
NO SPACE FOR NEW CAL. CLEAR
REGISTERS, 10-58
NOT ENOUGH SPACE ON DISK FOR
STORE, 10-57
O
one-port error-correction procedure,
11-4
open and short device verification,
9-6
open loop compared to phase locked
output in SRC tune mode, 7-9
operating temperature check, 5-13
operation check of A19 GSP and A18
display, 6-7
operation check of A9 CPU, 6-4
Option 004, 12-3
Option Cor., 10-15
option numbers correction constant
(test #56) adjustment, 3-34
options
003 3 GHz operation, l-7
004 step attenuator, l-7
006 6 GHz operation, 1-7
010 time domain, l-7
075 750 impedance, l-7
1CM rack mount flange kit without
handles, l-7
1CP rack mount flange kit with
handles, l-8
Index-14
AFN add 509 test port cable, l-8
AFP add 75 ohm test port cable, l-8
B02 external disk drive, 1-8
descriptions of, 13-40
options available, 1-7
oscilloscope, 1-3
oscilloscope check of reference
frequencies, 7-15
output frequency in SRC tune mode,
7-8
overall block diagram, 4-16
OVERLOAD ON INPUT R, POWER
REDUCED, 10-59
OVERLOAD ON REFL PORT, POWER
REDUCED, 10-58
OVERLOAD ON TRANS PORT, POWER
REDUCED, 10-59
P
P?, 10-60
packaging materials, 15-4
panel key codes, 6-8
parts
replaceable, 13-1
patterns test, 10-17
PEEK, 10-50
PEEK/POKE, 10-50
PEEK/POKE ADDRESS, 10-50
peek/poke menu, 10-50
performance testing, 2-l
performance test record, 2-50
performance tests, 2-1, 2-11
compression, 2-47
equipment required, 2-12
list of, 2-11
magnitude dynamic accuracy, 2-40
phase dynamic accuracy, 2-45
reflection test port output frequency
range and accuracy, 2-13
reflection test port output power
range and level linearity, 2-15
reflection test port output power
range and level linearity (option
004), 2-19
system trace noise, 2-36
test port crosstalk, 2-32
transmission test port input noise
floor level, 2-24
transmission test port input noise
floor level (option 075), 2-29
peripheral HP-IB addresses, 4-7
peripheral troubleshooting, 4-9
phase lock, 10-37
source, 12-15
phase lock (All) check, 7-37
phase lock and A3 source check, 7-8
PHASE LOCK CAL FAILED, 7-4,
7-39, 10-59
phase locked output compared to
open loop in SRC tune mode,
7-9
phase lock error, 7-4
phase lock error messages, 7-39
PHASE LOCK LOST, 7-4, 7-39, 10-60
photometer probe, l-3
pin locations on A19, 6-17
PLL AUTO ON OFF, 10-21
PLL DIAG ON OFF, 10-21
PLL PAUSE, 10-22
plotter HP-IB address, 4-7
plotter or printer check, 4-8
PLREF waveforms, 7-17
POKE, 10-50
Port 1 Op Chk., 10-12
Port 2 Op Chk., 10-12
POSSIBLE FALSE LOCK, 10-60
Post Reg., 10-10
post regulator
air flow detector, 12-8
display power, 12-9
green LEDs, 12-8
probe power, 12-9
shutdown circuit, 12-8
theory of operation, 12-8
variable fan circuit, 12-8
post regulator fuses
part numbers, 13-30
post regulator test point locations,
5-5
post-repair procedures, 14-22
power from source, 7-3
POWER LOSS, 10-5, 10-6
power meter (HP-IB), l-3
power meter HP-IB address, 4-7
power problems (broadband), 7-40
power sensor, 1-3
power splitter, l-3
power supply
theory of operation, 12-6
power supply block diagram, 5-24
power supply cable location, 5-8
power supply check, 4-11
power supply functional group block
diagram, 5-3
POWER SUPPLY HOT!, 10-61
power supply on A19, 6-13
power supply shutdown
Al5 green LED, 12-7
Al5 red LED, 12-7
theory of operation, 12-7
POWER SUPPLY SHUT DOWN!, 10-61
power supply troubleshooting chapter,
5-l
POWER UNLEVELED, 10-60
power up sequence check, 4-12
POW MET
not on, not connected, wrong addrs,
10-61
POW MET INVALID, 10-60
POW MET NOT SETTLED, 10-60
preregulated voltages
theory of operation, 12-7
preregulator
Index-15
removal, 14-12
theory of operation, 12-6
preregulator LEDs check, 4-l 1
preregulator voltages, 5-9
PRESET, 10-7
preset sequence, 4-3, 6-8
Pretune Cor., 10-14
Pretune Def., 10-14
preventive maintenance, 1 l-2
principles of microwave connector
care, 1-5
printer, l-3
PRINTER
not on, not connected, wrong addrs,
10-61
printer HP-IB address, 4-7
probe
power, 12-9
probe (photometer), l-3
PROBE POWER SHUT DOWN!, 10-62
probe power voltages, 5-19
procedures
A9 CC Jumper Position Adjustment,
3-5
ADC Offset Correction Constants
(Test #52), 3-21
Analog Bus Correction Constants
(Test #46), 3-10
Cavity Oscillator Frequency
Correction Constants (Test
#54), 3-24
Display Degaussing
(Demagnetizing), 3-45
Display Intensity Adjustments (Test
#49), 3-15
EEPROM Backup Disk Procedure,
3-38
Fractional-N Frequency Range
Adjustment, 3-46
Fractional-N Spur Avoidance and
FM Sideband Adjustment, 3-54
Index-16
Frequency Accuracy Adjustment,
3-49
Frequency Response Correction
Constants (Tests #53 and #57),
3-22
High/Low Band Transition
Adjustment, 3-51
IF Amplifier Correction Constants
(Test #51), 3-19
Initialize EEPROMs (Test 58), 3-37
Model Number Correction Constant
(Option 075 Only), 3-42
Option Numbers Correction
Constant (Test #56), 3-34
RF Output Power Correction
Constants (Test #47), 3-11
Serial Number Correction Constant
(Test #55), 3-32
Source Default Correction Constants
(Test #44), 3-8
Source Pretune Correction
Constants (Test #48), 3-14
Source Pretune Default Correction
Constants (Test #45), 3-9
Source Spur Avoidance Tracking
Adjustment, 3-58
Vertical Position and Focus
Adjustments, 3-43
pulse generator
source, 12-14
pulse generator (A7) check, 7-33
pulses (100 kHz), 7-16
R
R, A, and B inputs check, 8-4
rear panel
digital control, 12-13
part numbers, 13-10
Rear Panel, 10-10
rear panel board
removal, 14-14
rear panel cables, 13-16
rear panel hardware, 13-16
rear panel LEDs check, 4-l 1
rear panel removal, 14-6
rebuilt-exchange assemblies, 13-2
receiver
digital IF, 12-29
sampler/mixer, 12-28
theory of operation, 12-4, 12-23
receiver failure error messages, 8-2
receiver (measuring), l-3
receiver troubleshooting chapter,
8-l
RECORD ON OFF, 10-5
red LED on Al5
power supply shutdown, 12-7
REF (4 MHz) signal check, 8-8
reference
source, 12-14
reference, A12, 10-44
reference (A12) check, 7-13
reference frequencies check using
analog bus, 7-13
reference frequencies check using
oscilloscope, 7- 15
reference signal (4 MHz), 7-20
Reflection error-correction procedure,
11-4
reflection tracking characteristics
type-N test port (50 ohm), 2-6
type-N test port (75 ohm), 2-8
reflection tracking (ER), 11-15
REF signal At A11TP9, 7-17
removing
A8, 5-14
line fuse, 5-7
REPEAT ON OFF, 10-5
replaceable parts, 13- 1
abbreviations, 13-40
accessories, 13-38
cables, 13-12, 13-14, 13-16,
13-18-25
chassis, 13-28
display bezel, 13-26
front panel, 13-8
hardware, 13-14, 13-16, 13-30,
13-32, 13-34, 13-35, 13-36
labels, 13-37
major assemblies, 13-6
miscellaneous, 13-38
option descriptions, 13-40
ordering, 13-4
post regulator fuses, 13-30
rear panel, 13-10
rebuilt-exchange assemblies, 13-2
reference designations, 13-40
sampler, 13-18-25
source, 13-18-25
replacement sequence, 4-2
required tools, l-l
RESET MEMORY, 10-50
response calibration procedure, 11-6
return analyzer for repair, 4-2
revision (firmware) softkey,10-51
RF cable set, 1-3
RF output power correction constants
(test $47) adjustment, 3-11
RF power from source, 7-3
RGB outputs, 10-16
ROM, 10-7
S
safety, 15-1
before applying power, 15-7
earth ground, 15-7
general, 15-7
servicing, 15-7
safety symbols, 15-5
sales and service offices, 15-3
safes offices, 15-3
sampler
Index-17
part numbers, 13-18-25
Sampler Cor., 10-14
SAMPLER COR ON OFF, 10-23
sampler/mixer, 12-28
2nd LO signal, 12-28
high band, 12-28
low band, 12-28
mixer circuit, 12-29
SAVE FAILED. INSUFFICIENT
MEMORY, 10-62
SEGMENT, 10-6
selector switch check, 5-7
self diagnose softkey 10-7
self-test, 4-3
SELF TEST #n FAILED, 10-62
sensor (power), l-3
sequence check for power up, 4-12
Serial Cor., 10-15
serial number correction constant
(test #55) adjustment, 3-32
service and support options, 1-9
service center procedure, 4-2
service features, 10-19
service key menus, 10-l
service features, 10-19
service key mnemonics, 10-l
service mnemonic definitions, 10-52
SERVICE MODES, 1 O-20
service modes more menu, 10-23
service offices, 15-3
service test equipment, l-l
service tools list, l-l
servicing the analyzer, 4-2
setup
fractional-N spur avoidance and
FM sideband adjustment, 3-55
phase lock error troubleshooting,
7-4
setup check for disk drive, 4-8
setup check for plotter or printer,
4-8
Index-18
short and open device verification,
9-6
shutdown circuit
post regulator, 12-8
shutdown circuit on A8, 12-8
shutdown circuitry disable, 5-16
signal examination for phase lock,
7-37
signal separation
A30 dual directional coupler, 12-23
built-in test set, 12-23
theory of operation, 12-23
signals required for A10 assembly
operation, 8-9
SLOPE DAC, 10-21
softkeys, 10-2
source
All phase lock, 12-15
Al2 reference, 12-14
Al3 frac-N analog, 12-14
Al4 frac-N digital, 12-14
A3 source, 12-15
A7 pulse generator, 12-14
high band theory, 12-19
low band theory, 12-16
part numbers, 13-18-25
source, 12-15
theory of operation, 12-3, 12-14
source and All phase lock check,
7-8
source attenuator
theory of operation, 12-3
Source Cor., 10-14
Source Def., 10-14
source default correction constants
(test #44) adjustment, 3-8
Source Ex., 10-12
source group assemblies, 7-l
source group troubleshooting
appendix, 7-39
source match (Es), 11-13
source match (reflection)
characteristics
type-N test port (50 ohm), 2-6
type-N test port (75 ohm), 2-7
source match (transmission)
characteristics
type-N test port (50 ohm), 2-6
type-N test port (75 ohm), 2-8
SOURCE PLL ON OFF, 10-21
source power, 7-3
SOURCE POWER TRIPPED, RESET
UNDER POWER MENU, 10-62
source pretune correction constants
(test #48) adjustment, 3-14
source pretune default correction
constants (test #45) adjustment,
3-9
source spur avoidance tracking
adjustment, 3-58
source troubleshooting chapter, 7-l
spectrum analyzer, l-3
speed
fan, 5-22
splitter (power), l-3
spur avoidance and FM sideband
adjustment, 3-54
SPUR AVOID ON OFF, 10-24
SPUR TEST ON OFF, 10-23
SRC ADJUST DACS, 10-21
SRC ADJUST MENU, 10-20
SRC TUNE FREQ, 10-20
SRC tune mode frequency output,
7-8
SRC tune mode phase locked output
compared to open loop, 7-9
SRC tune mode waveform integrity,
7-9
SRC TUNE ON OFF, 10-20
stable HI OUT signal in FRACN TUNE
mode, 7-35
static-control table mat and earth
ground wire, 1-3
status terms for test, 10-4
step attenuator, l-3
STORE EEPR ON OFF, 10-23
stuck key identification, 6-8
support and service options, l-9
SWEEP MODE CHANGED TO CW
TIME SWEEP, 10-63
Sweep Trig., 10-10
symbol conventions, 10-52
symbols
instrument markings, 15-6
safety, 15-5
SYSTEM IS NOT IN REMOTE, 10-63
system performance uncorrected,
11-9
system verification, 2-1, 2-3
procedure, 2-9
system verification tests, 10-3, 10-13
Sys Ver Init., 10-13
SYS VER TESTS, 10-4
sytem verification
cycle, 2-4
description, 2-3
kit recertification, 2-4
measurement uncertainty, 2-4
T
table of service tools, l-l
temperature check, 5-13
terms for test status, 10-4
test 44, 10-14
test 45, 10-14
test 46, 10-14
test 47, 10-14
test 48, 10-14
test 49, 10-14
test 50, 10-14
test 51, 10-14
test 52, 10-14
Index-19
test 53, 10-14
test 54, 10-14
test 55, 10-15
test 56, 10-15
test 58, 3-37, 10-15
test 59, 10-16
test 60, 10-16
test 61, 10-16
test 62, 10-16
test 63, 10-16
test 64, 10-16
test 65, 10-16
test 66, 10-17
test 67-69, 10-17
test 70, 10-17
test 71, 10-17
test 72, 10-17
test 73-74, 10-17
test 75, 10-18
test 76, 10-18
test 77, 10-18
test 78, 10-18
test 79, 10-18
test 80, 10-18
TEST ABORTED, 10-63
test cables, 9-5
test descriptions, 10-7
test equipment for service, 1-1
TEST OPTIONS, 10-5
test options menu, 10-5
Test Pat 1., 10-17
Test Pat 10., 10-18
Test Pat 11., 10-18
Test Pat 12., 10-18
Test Pat 13., 10-18
Test Pat 14., 10-18
Test Pat 15., 10-18
Test Pat 2-4., 10-17
Test Pat 5., 10-17
Test Pat 6., 10-17
Test Pat 7., 10-17
Index-20
Test Pat 8-9, 10-17
test patterns, 10-3
test port connector inspection, 9-3
tests
adjustments, 10-14
display, 10-16
external, 10-12
internal, 10-7
patterns, 10-17
system verification, 10-13
tests (diagnostics), 6-11
test set, 12-23
theory of operation, 12-4
tests menu, 10-3
test status terms, 10-4
theory of operation, 12-l
+5V digital supply, 12-7
Al5 green LED, 12-7
Al5 preregulator, 12-6
Al5 red LED, 12-7
A3 source, 12-3, 12-14
A8 green LEDs, 12-8
A8 post regulator, 12-8
A8 shutdown circuit, 12-8
air flow detector, 12-8
digital control, 12-9
display power, 12-9
functional groups, 12-5
line power module, 12-7
microprocessor, 12-4
power supply, 12-6
power supply shutdown, 12-7
preregulated voltages, 12-7
probe power, 12-9
receiver, 12-4, 12-23
signal separation, 12-23
source attenuator, 12-3
test set, 12-4
variable fan circuit, 12-8
tool kit, l-3
tools
assembly replacement, 14-2
tools for service, l-l
transmission tracking characteristics
type-N test port (50 ohm), 2-7
type-N test port (75 ohm), 2-8
transmission tracking (ET), 11-19
TROUBLE! CHECK SETUP AND
START OVER, 10-63
troubleshooting
1st LO signal at sampler/mixer,
8-12
Al0 by substitution or signal
examination, 8-8
All phase lock, 7-37
All phase lock and A3 source
check, 7-8
Al2 reference, 7-13
A13/A14 Fractional-N, 7-24
Al4 Divide-by-N Circuit Check,
7-29
Al5 preregulator, 5-9
Al/A2 front panel, 6-7
A7 pulse generator, 7-33
accessories, 9- 1
broadband power problems, 7-40
diagnostics, 4-3
digital control, 6-l
disk drive, 4-8
fan, 5-22
faulty group identification, 4-10
front panel, 6-7
HP-IB systems, 4-7
one or more inputs look good, 8-11
phase lock error, 7-4
plotters or printers, 4-8
receiver, 8- 1
self-test, 4-3
source, 7-1
systems with controllers, 4-9
systems with multiple peripherals,
4-9
when all inputs look bad, 8-7
YO coil drive check with analog
bus, 7-11
troubleshooting power supply, 5-l
troubleshooting source group
appendix, 7-39
U
uncertainty
measurement, 2-4
measurement window, 2-4
uncorrected performance, 11-9
USE SENSOR A/B, 10-6
V
variable fan circuit, 12-8
VCO (A14) exercise, 7-28
VCO range check frequencies, 7-24
verification kit 7 mm, l-3
verify calibration kit devices, 9-4
vertical position and focus
adjustments, 3-43
voltage indications
post regulator, 12-8
voltages
Al5 preregulator check, 5-9
A19 GSP, 6-14
A8, 5-14
display power supply, 6-13
fan, 5-22
front panel probe power, 5-19
YO- and YO+ coil drive voltage
differences with& SOURCE
PLL OFF, 7-13
voltages for post regulator, 5-5
voltmeter, l-3
VRAM bank., 10-16
VRAM/video, 10-16
Index-21
W
walking one pattern, 6-16
warranty, 15-2
limitation of, 15-2
warranty explanation, 4-2
waveform integrity in SRC tune mode,
7-9
wrist strap and cord (antistatic), l-3
Index-22
WRONG DISK FORMAT, INITIALIZE
DISK, 10-63
Y
YO coil drive check with analog bus,
7-11
YO- and YO+ coil drive voltage
differences with& SOURCE PLL
OFF, 7-13
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