QUANTICS W9GR Digital Signal Processor ASSEMBLY INSTRUCTIONS

QUANTICS
P. O. Box 2163
Nevada City, California 95959-2163
ASSEMBLY INSTRUCTIONS
(version 6.6)
for the
W9GR DIGITAL SIGNAL PROCESSOR
As featured in the September 1992 issues of both QST and QEX Magazines
To use these instructions and build this kit,
you should be capable of constructing a PC board
from a parts list and schematic diagram, recognize
electronic component parts, identify integrated
circuit pin numbers, and solder. Potential kit
builders lacking these skills are referred to The
Radio Amateur’s Handbook. This is not a kit for
beginners!
The PC board is double sided with silk
screen and solder mask. The "silk screen" is the set
of white markings (such as "C14" and "R5") on
the PC board which guides you in inserting the
parts at the correct location. The components
mount on the side with the silk screen.
The dark colored solder mask will help to
avoid "solder bridges" between adjacent leads. It
also provides insulation between the traces on the
board and the exposed metal parts on the bottom
of some of the IC sockets. Because of this, be
careful not to scratch the solder mask; otherwise,
there could be shorts or intermittent shorts
between the IC sockets and the traces which run
underneath the IC sockets.
The installation of parts progresses from
the shortest parts, such as IC sockets and resistors,
to the tallest parts such as the electrolytic
capacitors and heatsink.
This double sided board has plated
through holes. At various places on the board, the
traces on the top side need to connect to traces on
the bottom side. A plated through hole called a
"via" performs this function. If you look at the
board, you can see quite a few examples of "vias"
under U1, the largest IC on the board. Notice that
the vias have somewhat smaller tinned copper
pads than the pads where the parts mount. When
you install parts, do not install them in these "via"
holes, which may be close to the hole where the
part is supposed to go. Most of the parts have silk
screened lines which will help you avoid making
this error. C27 and C28 are examples of places
where you should be careful to insert the capacitor
into the component holes and not the nearby "via."
If you find you made a mistake and need
to unsolder and remove a part, be careful so as to
not remove the plating or the pads from the plated
through hole. Use a minimum amount of heat, and
either a vacuum solder removal device or wire
braid to remove the solder from the hole.
The electrolytic capacitors are polarized,
and must be installed in a particular direction.
There is a "+" mark on the PC board where the "+"
or positive end of the capacitor must be installed.
Sometimes capacitors have the "-" end marked
instead of the "+" end. In this case, insert the
unmarked end, which will be the "+" end, into the
"+" hole on the PC board.
Similarly, the two diodes have a circular
band at one end; this marked end should match up
with the markings on the silk screen.
The integrated circuits must also be
inserted in the correct direction. Each IC will have
either a notch or a "dimple" at one end. This end
of the chip must match the silk screen markings on
the board.
The integrated circuits used in this kit are
susceptible to electrostatic damage. When
handling the ICs, use standard procedures to avoid
static damage. In brief, ground the circuit, the ICs,
and most importantly yourself before handling
static sensitive parts.
When you insert the ICs into their sockets,
it is very important to check that the pins are all
straight and that the IC is pushed into its socket
straight. Otherwise, an IC pin can easily be bent
under the chip as you insert it, and visual
inspection will not reveal the problem!
If you need to remove a chip from its
socket, insert a small screwdriver between the
socket and the chip alternately at one end then the
other, and back the chip out straight so as not to
bend its pins.
Review the following parts list and
identify all parts before soldering them into the
board. Notice that one of the 20 pin IC sockets
resembles a wire-wrap type, with its pins bent 90
degrees to accommodate the LED bargraph
display. Also be aware that there may be several
different styles of capacitors of the same value: for
instance 0.1 uF mylar and 0.1 uF ceramic disc.
(The disc ceramic capacitors are round and thin
while the mylars have a more rectangular shape.)
Some parts may be marked with a number
that indicates the value indirectly. According to
this convention, the first two digits are followed
by a number of zeros which is indicated by the
third digit. "103" on a disc ceramic capacitor
would indicate 10 followed by 3 zeros: 10000 pF
or equivalently, 0.01 uF. The 22 pF capacitors
may be marked "220J03." The "220" part of the
marking means "22 followed by no zeros." So this
means 22 pF, not 220 pF!
Parts List
Unless otherwise specified, all resistors are 1/4 watt 5% and capacitors are 10% tolerance. Some
of the capacitors may be marked with a three digit number where the last digit represents the number of
zeros to follow the first two digits. For example, "103" would translate to 10000 picofarads, which would
be the same as 0.01 uF (0.01 microfarad). Sometimes these numbers are combined with other digits or
letters. Any of the following CPU variants will work and may be supplied as U1: TMS320C10, TMS32010,
TMS320P15, TMS320E15, or TMS320C15.
Quantity
2
Reference Designator(s)
C6, C11
2
2
2
C2, C31
C13, C32
C9, C4
3
11
2
3
2
C5, C8, C10
C1, C15, C16,
C18, C22, C25,
C26, C27, C28,
C29, C30
C7, C12
C3, C14, C19
C20, C21
3
2
C17, C23 C24
D1, D2
2
1
L1, L2
LED1
1
3
1
2
2
3
1
2
1
2
1
2
1
1
10
1
1
1
1
1
2
R1
R2, R3, R5
R4
R6, R12
R7, R13
R8, R14, R15
R9
R10, R11
R16
R17, R22
R18
R19, R21
R20
R23
R24, R25, R26, R27,
R28, R29, R30, R31,
R32, R33
S1
S2
S3
U1
U2
U3, U4
1
2
1
U5
U6, U7
U8
1
1
1
U9
U10
Y1
1
2
1
1
1
4
1
Description
0.001 uF mylar
(may be marked "102," "102J," "102K," or "2A102KT")
0.001 uF ceramic 20% (may be marked "102" or "102Z")
0.01 uF ceramic 20% (may be marked "103" or "103Z")
0.022 uF mylar
(may be marked "223," "223J," "223K," or "2A223KT")
0.1 uF mylar (may be marked "104," "104K," or "2A104KT")
0.1 uF ceramic, 20%
(may be marked "104," ".1Z," ".1M," or "104Z")
1 uF electrolytic 16V
10 uF electrolytic 16V
22 pF silver mica or ceramic
(may be marked "220J03" or "22PJ3")
220 uF electrolytic 16V
1N4001 silicon diode (diodes with higher voltage ratings such as
1N4002, 1N4003, 1N4004 etc. may be supplied)
10 uH RF chokes
10 segment LED bargraph, Radio Shack 276-081B
or equivalent
100 k ohms (brown-black-yellow-gold)
15 k ohms (brown-green-orange-gold)
30 k ohms (orange-black-orange-gold)
4300 ohms (yellow-orange-red-gold)
4700 ohms (yellow-purple-red-gold)
3900 ohms (orange-white-red-gold)
22 k ohms (red-red-orange-gold)
10 k ohms (brown-black-orange-gold)
100 k ohm pot, linear taper
1.8 k ohms (brown-gray-red-gold)
39 ohms (orange-white-black-gold)
1000 ohms (brown-black-red-gold)
2.7 ohms (red-purple-gold-gold)
100 ohms (brown-black-brown-gold)
330 ohms (orange-orange-brown-gold)
DPDT toggle switch
SPST momentary pushbutton
SPDT toggle switch (for BIO function)
TMS320C10, or TMS32010 variant digital signal processor CPU
AD7569 analog interface subsystem
74S472 bipolar PROMs (not supplied with multi-program kit)
(programmed with desired firmware function)
74HC139, 74LS139, or 74F139 decoder
74HC374 or 74LS374 octal flip flop
LF347, TL074, or LM348
quad opamp
LM380 audio power amplifier
LM340T-5 or 7805 TO-220 5 volt regulator
20 MHz fundamental crystal,
20 pF load
TO220 heatsink
14 pin IC sockets
16 pin IC socket
24 pin "skinny DIP" (0.3") IC socket
40 pin IC socket
20 pin IC socket
20 pin right angle socket
(for LED bargraph)
2
amount of thermal grease (not supplied) between U10
and the heat sink. If the heatsink has solder tabs which
would interfere with the voltage regulator U10 leads,
cut them off. Use the #4 hardware supplied to mount
U10 and the heatsink to the board.
PC BOARD ASSEMBLY
❏ 1. First install and solder each of the fixed resistors.
❏ 2. There are three pads at jumper position W2 which
are used to configure the DSP for single function or
multi function operation. If you are building the
single-function DSP kit (with TMS32010 or
TMS320C10 processor with firmware in bipolar
PROMs), take one of the clipped-off resistor leads and
solder it between the center pad at jumper W2
(MC/MP-) and the "0" pad. There is a silk screened line
between the two pads. If you are building the kit with
the Multi-Program chip (TMS320P15), solder the wire
between the center pad and the "1" pad. NOTE: the silk
screened "1" is hard to see because it falls on top of a
"via" hole. DO NOT solder the jumper wire to the via
hole! The "1" pad is square, not round. (The "0"
position tells the TMS320C10 processor to look for
firmware in the external bipolar PROMs at U3 and U4.
The "1" position tells the TMS320P15 processor to use
its internal program.)
❏ 12. A right angle 20 pin IC socket is supplied for the
LED bargraph display. In most applications the PC
board will mount horizontally and the LED bargraph
will poke through an opening in your front panel.
The printed circuit board is drilled to accept a
LED bargraph display socket (DS1) with either 0.1" or
0.2" row spacing. So, there are three rows of holes on
the board, and the back two rows are connected
together. 0.1" sockets are generally supplied with this
kit. Therefore, the LED bargraph socket should be
installed in the front two rows of PC board holes. The
three rows of holes for the LED bargraph socket will
look like this:
●
❘
●
●
●
❘
●
●
●
❘
●
●
●
❘
●
●
●
❘
●
●
●
❘
●
●
●
❘
●
●
●
❘
●
●
●
❘
●
●
●
❘
●
●
________EDGE OF PC BOARD________
W2
●
●
■
^
^
^ use these 3 holes!
●
< use this row
< use this row
❏ 13. Do not insert the integrated circuits into their
sockets just yet! After the "Installation in Your Circuit
& Enclosure" section below, a "smoke test" will be
performed to make sure that the supply voltage applied
to the logic integrated circuits is not excessive.
< NOT THIS HOLE!
❏ 3. Install and solder the two 1N4001 silicon diodes
(D1 & D2). Be sure to match the polarity band on the
diode to the one on the silk screen.
INSTALLATION IN YOUR
CIRCUIT & ENCLOSURE
❏ 4. Install and solder the IC sockets. Do not install an
IC socket at LED1 (the LED bargraph). Be sure to
align the notch at the notched end of the socket with the
notch on the PC board silk screen. Sometimes sockets
will have a beveled mark, a dot, or some other
distinguishing characteristic at pin 1 instead of a notch.
(Pin 1 is the lower left hand corner viewed from the top
with the notch on the left; pin numbers increase
counterclockwise from pin 1.) (Note: if you look at the
board from the "front" end, where the LED bargraph is
located, all the notched ends go to the left.)
Next install the PC board in your enclosure. (If
there is room to spare, you may want to install it in your
speaker cabinet.) The switches and volume control are
mounted on the front panel of your enclosure rather
than on the PC board. The digital signal processor is a
snug fit inside a Radio Shack 270-253A cabinet. Use
long screws or spacers to raise the board up about an
inch and help the fit. If you mount the board low in the
box it may be necessary to either file the board (be
careful not to destroy the ground bus that runs around
the outside of the board) or to re-bend the rear of the
box to allow a little bit more front to back clearance.
Another enclosure which works well for this
project, but which may be harder to find, is the
GC/Thorsen model 16-143. This is an ABS plastic box,
with inside dimensions of 6" W x 6.25" L x 2.5" H.
Another possible enclosure is the Radio Shack
270-272A enclosure, which has enough room for an
internal power supply and/or a large extra filter
capacitor.
High speed CMOS, as used in this project,
produces EMI in prodigious quantities. As with most
any project designed for use in a ham environment, it is
highly recommended that you shield the PC board by
installing it in a metal cabinet and bypass signals going
into and out of the cabinet. Some of this EMI bypassing
is already provided on the PC board itself. If you do not
shield the digital signal processor, at least its
autonotcher firmware will help clean up some of its
own radiated birdies which you might tune across!
Follow these steps, improvising as necessary
to suit your installation:
❏ 5. Install and solder the two RF chokes, L1 and L2.
❏ 6. Install and solder the ceramic disc capacitors
(0.001 uF, 0.01 uF, 0.1 uF). Notice that C5, C6, C8,
C11, and C10 are mylar capacitors, not ceramic.
❏ 7. Install and solder the (usually green colored) mylar
capacitors (0.001 uF, 0.022 uF, 0.1 uF). Again, notice
that mylar capacitors, not ceramic capacitors, are
installed at C5, C6, C8, C11, and C10.
❏ 8. Install and solder the two 22 pF capacitors at C20
and C21.
❏ 9. Install and solder the rest of the electrolytic
capacitors, being careful to observe the polarity
markings on the board and on the capacitors.
❏ 10. Install and solder the 20 MHz crystal at Y1. If
you leave a little lead length on this component, it will
not break off if inadvertently bent over. The crystal
supplied may have a third wire soldered to the metal
case. If it does, cut the wire off.
❏ 1. Wire the volume control pot to the pads at R16. If
the pot is mounted with its lugs down and if you look at
the board from the LED bargraph end, then the leftmost
lug should mount to the leftmost pad (square pad); the
center lug connects to the center pad, etc.
❏ 11. In this step, the voltage regulator (U10) is
mounted together with a heatsink to the PC board, and
then the leads are soldered to the board. Use a small
3
After this test is completed, disconnect the power.
❏ 2. Connect the reset switch S2 (SPST momentary
contact) to the S2 pads along the front edge of the PC
board.
❏ 11. After you have verified that there is not excessive
voltage on the nominally 5 volt output of the voltage
regulator IC U10, disconnect power and insert the
integrated circuits into their sockets, being careful to
insert them straight and with the proper orientation. On
most ICs it is usually necessary to bend the leads
slightly inward so that they will go into the socket
straight. Bend the leads as a group against a flat surface.
Your kit may be supplied with "LS" (low power
Schottky) parts instead of "HC" (high speed CMOS).
The LS parts are faster, avoiding a possible logic timing
problem (see Technical Correspondence, February
1993 QST). Use the supplied 74LS139 in place of the
74HC139 (U5), and the two 74LS374 parts in place of
the 74HC374s (U6 and U7).
❏ 3. Connect the in/out switch S1 (DPDT toggle
switch) to the pads at S1. If the switch is held above the
S1 printed circuit board pads with the toggle up and the
terminals down, then the upper left pad (looking at it
from the toggle end) connects to the upper left switch
terminal, the lower left pad connects to the lower left
switch terminal, etc. In this orientation, when the switch
is flipped to the right, the DSP will be "in."
❏ 4. Connect the BIO switch S3 (SPDT toggle switch)
to the W1 jumper pads. The center terminal on the
switch goes to the center jumper pad, the lower
terminal goes to the "1" pad, and the upper terminal
goes to the "0" pad. With these connections and with
the BIO switch S3 flipped "up," the BIO pin will have a
logic "1" applied to it.
❏ 12. Insert the LED bargraph into its socket. The
markings, if any, are usually along the pin 1-10 edge,
which goes down in this application. If the bargraph
does not light up you can try reversing it; we have
found a few bargraphs with the lettering along the pin
11-20 (top) edge.
❏ 5. Connect the +12 pad E1 to a connector which will
supply a reasonably good source of +12 volt DC. (Do
not actually apply power yet.) Most "wall mount"
transformers have too much AC ripple at the 1/2 amp
load current required. If you elect to use one of these
"wall mount" supplies, first be sure it has adequate
ratings (at least 1/2 amp) and then install a 4700 uF or
larger value capacitor of suitable voltage ratings to
reduce the ripple. The power supply voltage may be as
low as 8 volts and as high as 16 volts, but more audio
output power will be available with a higher supply
voltage.
❏ 13. Install the firmware IC PROMs. They come in
pairs, and will be marked "high" and "low" or "U4" and
"U3." Be sure that each PROM of the pair is inserted
into the correct socket. This step is not necessary if you
bought the "multi-program" version of the kit, in which
U3 and U4 are not used.
OPERATION
❏ 6. Connect pad E2 to ground. This ground point
should also connect to your radio’s ground (or the
ground of the connector which accepts the radio’s audio
output), the speaker’s ground return (or the ground
connection on the jack you use for the speaker), and the
power supply ground.
To make best use of the 8 bit dynamic range
and the noise filter/notcher algorithm, it is important to
make sure the input signal is at the expected level. The
recommended method of operation is to set the receiver
audio gain so that on the strongest signals, the top LED
on the bargraph display occasionally comes on. Once
the receiver gain is properly adjusted, do not touch it;
instead use the AF gain control on the processor to
adjust speaker volume. This procedure will keep the
A/D and D/A precision highest, and the quantizing
noise lowest. Most modern receivers have good AGC
characteristics with a flat AGC slope, the result being
consistent audio level for both strong and weak signals.
(You might want to add a separate audio AGC circuit to
avoid having to set the receiver’s AF gain.) If your
receiver’s audio level is inconsistent, you may
experience occasional overloads of the digital signal
processor. The distortion in this case will be quite
obvious, because instead of simply clipping, many DSP
systems including this one tend to "wrap around,"
which maps positive peak overloads into negative peaks
and vice versa. If this happens, simply turn down the
audio input a tad.
The standard autonotcher/denoiser firmware
uses the Widrow-Hoff LMS adaptive filtering
algorithm. The front panel "BIO" or mode switch
selects either the noise reduction ("denoiser") mode or
the automatic notch filter mode. The noise reducer
mode is most effective against hiss and thermal noise
but also reduces impulse noise and static crashes. This
mode reduces listener fatigue and is recommended for
long-term monitoring. The automatic notch mode
eliminates multiple carriers very quickly, within a few
milliseconds. Tuner-uppers, CW interference, carriers,
and other forms of undesired audio tones are quickly
eliminated. If a carrier comes on your frequency, all
you will hear will be a subtle "click" as the automatic
❏ 7. The speaker output of your radio should connect to
pad E3.
❏ 8. Connect your speaker to pad E4.
❏ 9. If you include a "headphone" output jack, you
might want to put a 100 ohm resistor in series with the
headphone output (but not the speaker output) to
compensate for the high sensitivity of most "walkman"
type headphones.
❏ 10. Now comes the "smoke test." For this test it is
best to use a 12 volt power supply which is current
limited to 1 ampere. If you do not use a current limited
power supply, there is the danger of burning traces off
the board if there is a short. With none of the integrated
circuits installed in their sockets (except for U10, the
soldered-in voltage regulator), apply power and turn on
the switch S1. Using a voltmeter, connect its negative
lead to ground. While viewing the board from the LED
bargraph end, at U10 the leftmost pin should have
approximately 12 volts present. (Depending on your
power supply, the voltage may be as low as 8 volts or
as high as 16 volts.) There should be zero volts at the
middle pin. The rightmost pin must have 5 volts +/- 0.5
volts. If there is more than 5.5 volts at the rightmost pin
of U10, do not install the socketed integrated
circuits. If you do, they may be destroyed and the
warranty will be voided. Check the installation of
components and correct the problem before proceeding.
4
Program #3 is an optimized denoiser filter
only. The denoising function is somewhat more
effective than the combined switchable function in
program #1. The front panel mode switch switches the
filter in or out.
Program #4 is an optimized automatic notch
filter only. This automatic notch function is optimized
in the sense that it has less of an effect on some voice
signals than the autonotcher function in program #1.
The front panel mode switch switches the filter in or
out.
Programs #5-9 are CW filters of different
center frequencies and bandwidths. The front panel
mode switch switches the filter in or out.
Filter 5 is a 400 Hz Linear Phase CW Filter
(200 Hz bandwidth).
Filter 6 is a 600 Hz Linear Phase CW Filter
(200 Hz bandwidth).
Filter 7 is a 750 Hz Linear Phase CW Filter
(200 Hz bandwidth).
Filter 8 is a 1000 Hz Linear Phase CW Filter
(200 Hz bandwidth).
Filter 9 is a 750 Hz Linear Phase Ultra-Narrow
CW Filter (30 Hz bandwidth). This filter may be useful
for very weak or very noisy CW signals (for example
moonbounce), or for machine copied CW.
Program #10 is a HF packet (1600/1800 Hz) or
RTTY (2125/2295 Hz) bandpass filter. The front panel
mode switch selects either the packet tones (BIO=0) or
the RTTY tones (BIO=1).
The packet filter in the DSP has the following
specifications:
notch acquires.
For those using the LMS denoiser/notcher
firmware, the recommended mode of operation is to
leave the BIO switch S3 in the "0" position, which is
the denoiser mode. On most signals this mode gives the
best sound. Then when carriers and CW interference
appear, throw the switch to the "UP" (BIO=1) position,
which actuates the automatic notch mode. If you expect
frequent CW interference, you might want to leave the
switch in the BIO=1 (automatic notch) position all the
time.
For users of the CW filter firmware, the BIO
switch has a different function. When the BIO switch is
UP (BIO=1) then the CW filter operates normally.
When BIO is set to 0, the CW filter is bypassed.
Switching the BIO pin to 0 momentarily can help you
find signals that are outside the CW filter passband.
Note: when BIO is switched to 0 (filter out),
may be aliasing on CW signals above 1 kHz. This is
normal and is due to the oversampling algorithm. When
the filter is in, which is the normal operational mode,
the aliasing will disappear.
An explanation of the algorithms used in this
digital signal processor and a description of the
hardware are in the September 1992 QST magazine
article "Low Cost Digital Signal Processing for the
Radio Amateur" by Dave Hershberger, W9GR. For
those looking for a thorough mathematical treatment of
the firmware noise reduction and autonotcher
algorithm, refer to "Using the LMS Algorithm for
QRM and QRN Reduction" by Dr. Steven E. Reyer,
WA9VNJ, and David L. Hershberger, W9GR, in
September 1992 QEX magazine.
If you are using the multi-program chip with
its 10 different digital filters, you must "select" a
program when the unit is first powered up. When you
hit the reset button or power up the unit with the
Multi-Program chip, a single LED segment will light
and move across the display, staying lit for about one
second at each segment. Each of the 10 segments
corresponds to a particular LMS filter, CW filter, etc.
If you toggle the BIO switch when a particular LED is
lit up, then the corresponding program will begin. If
you don’t do anything, then after one pass across the
bargraph (about 10 seconds) the "default" program will
execute (#1, the LMS noise filter & automatic notch
filter). As soon as the program is selected, then the BIO
switch (mode switch) has a new function depending on
which program is running (for most programs, the
mode switch is a filter IN/OUT select).
When the DSP is in the "menu select" mode
where the 10 LEDs are lighting up in succession, the
DSP will pass unprocessed audio through to the output.
This will allow you to hear the received signal
"straight-through" while you are selecting the DSP
mode. For those with vision impairments or who would
rather not watch the LEDs, a short "beep" will be heard
from the speaker as each menu LED comes on. The
first "beep" is a little bit longer than the other nine.
If you are running one program and want to
change programs, simply hit the reset button (or cycle
power) and select the desired program using the LED
display and BIO (mode) switch.
Program #1, the "standard" firmware, is the
same combination noise reducer and automatic notch
filter (noise reduction or automatic notching), described
above.
Program #2 is a simultaneous automatic notch
and denoiser filter, which while effective, is somewhat
of a compromise compared with programs #1, #3, and
#4. The front panel mode switch switches the filter in or
out.
Passband: 1550-1850 Hz (at -0.3 dB)
Stopband: below 1325 Hz and above 2075 Hz
(at -47 dB)
The ripple bandwidth (0.3 dB) is 300 Hz and the -3 dB
bandwidth is about 400 Hz.
The RTTY filter specifications are as follows:
Passband: 2075-2345 Hz (at -0.6 dB)
Stopband: below 1850 Hz and above 2570 Hz
(at -49 dB)
The ripple bandwidth (0.6 dB) is 270 Hz and the -3 dB
bandwidth is about 350 Hz.
Both of these FSK filters are 120th order FIR
filters with a sampling frequency of approximately
14 kHz.
An advantage of the multi-program chip is
lower power consumption: by removing the
power-hungry bipolar PROMs, the current requirement
is reduced from 400 mA to 175 mA at normal audio
levels.
MODIFICATIONS of EARLIER KIT VERSIONS
You may have heard of several modifications
to the Digital Signal Processor. These modifications
were devised by several amateurs (WA3RMX and
W6GO) to correct a problem with the two earlier
versions of the PC board (REV A and REV B). In these
earlier PC boards, there were digital traces which were
located close to analog traces, resulting in unwanted
coupling of digital noise into U9, the audio power
amplifier chip. The "REV C" board supplied with this
kit has a completely different physical arrangement of
parts which eliminates the need for these modifications.
Although the electrical circuit is identical to the earlier
versions, the physical layout is different and improved.
Therefore, you will not need to make any of these
5
fastest way to get your kit working.
modifications.
Because the physical layout is new, you will
notice that the appearance of your PC board will be
somewhat different than the photographs in QST and
the illustrations accompanying these instructions, which
show the earlier versions of the PC board. Refer to the
illustrations only for ideas on mounting the PC board
and installation, and not for component location.
❏ 6. Some of the shorts we have found have been due
to very small dendrites of solder which worked their
way under the solder mask. You might have to look
very closely, with a magnifying glass, to find them!
❏ 7. We have learned of several failures which have
occurred after weeks or months of normal operation.
These failures were due to residual debris and flux from
soldering working through the solder mask and
contacting nearby traces. These failures may not be
"zero ohm" shorts but may measure in the tens,
hundreds, or thousands of ohms. If you experience such
a delayed failure, it may be cured by using a small
brush and chemical flux remover. Alternatively, you
might try carefully and gently scraping off the flux and
soldering residue from around each pad with a small
screwdriver or awl, being careful not to scrape off the
traces.
IN CASE OF DIFFICULTY
❏ 1. Check your soldering for unconnected pins, cold
solder joints, and/or solder bridges. This is a very
important troubleshooting step! Almost every kit
which has been returned to us for repair has not
worked because of simple soldering defects! The odds
are that you can save yourself a lot of time and possible
embarrassment if you carefully check your soldering
work for unsoldered connections, "cold" joints, solder
bridges, and scratched off PC board traces. Use a
magnifying glass to find suspicious connections, and
re-solder them. Don’t rely on the solder mask to be an
infallible insulator against sloppy soldering. Remove
solder blobs which encroach over the solder mask or
onto nearby "vias." Use a soft brush to remove metallic
and conductive solder dust and debris. In several cases,
the soldering problem was found underneath an IC
socket, necessitating removal and replacement of the
socket! Sometimes capillary flow can draw solder up
through vias and holes to the other side of the board. If
this happens underneath a socket, it could be very hard
to find the problem. It’s really true what Heathkit used
to say in their manuals: 90% of the problems with
Heathkits were due to bad soldering.
❏ 8. Make sure that all grounds are connected together
among the devices that connect to the DSP: the 12 volt
power supply, the audio source (receiver), the DSP unit
itself, and the speaker. Make sure that the "hot" and
"ground" wires in cable connectors are not reversed.
❏ 9. Check wiring to the off-board components (the
volume control and switches).
❏ 10. Check to make sure that the jumper wire at W2 is
installed properly. It should NOT be soldered to the
small "via" hole with a silk screened "1" on it. If the
jumper wire is soldered between the square hole and the
small "via" hole with the "1" on it, then the one of the
data bus lines will be shorted to +5 volts, the second
LED on the display will never light up, and the CPU
chip may be damaged!
❏ 2. Check all of the integrated circuits to see if pins
are bent underneath the chips. With the power off, use
an ohmmeter to check for continuity from the IC pin to
the pad underneath the board. Or, you can remove each
chip for visual inspection and then reinstall them.
❏ 11. Check the two diodes at D1 and D2; the banded
ends should be oriented towards the front (LED
bargraph) end of the board.
❏ 3. Use an oscilloscope if you have one available to
look for "sick" looking (i. e. lack of full logic swings)
digital waveforms. If you find a sick looking logic
waveform, it may be shorted to a neighboring trace.
Look for bad soldering somewhere on that node. Bear
in mind that many of the logic signals on the board are
"tri-state" meaning that the drivers go high impedance
at certain times. You may see what looks like "sagging"
voltages; this is normal on some nodes such as the data
bus. Look for the logic swings to go all the way to a
valid logic 1 and a valid logic 0 at least some of the
time. With the power off, use an ohmmeter to check for
shorts to nearby traces and IC pins.
❏ 12. Check the DC voltages at various points
throughout the circuit. With power on but no signal
applied, you should measure the following DC
voltages:
U8 pin 8: 5.0
U8 pin 7: 5.0
U9 pin 2: 0.0
U2 pin 23: 1.25
U2 pin 24: 5.0
U9 pin 8: approximately half of
supply (about 6 volts)
❏ 4. From our statistical experience so far, there is at
least a 95% probability that any given non-working kit
has soldering defects. To search for soldering defects,
begin by first going around each chip with an
ohmmeter. Check to see if pin 1 is shorted to pin 2, pin
2 to 3, etc. on each chip. If you find pins shorted
together, refer to the schematic to see if they are
supposed to be connected; sometimes that will be the
case.
U8 pin 1: 5.0
U8 pin 14: 5.0
U9 pin 3: 0.0
U2 pin 5: 5.0
the +12 volt power
❏ 13. Push the "reset" pushbutton. With the button held
down, the voltage at U2 pin 5 should go to zero. When
you release the switch, the voltage should return to 5
volts.
❏ 14. If you have an oscilloscope, you can trace the
signal through the unit. U8 pin 1 is the output of the
input buffer amplifier. U8 pin 7 is the output of the
input antialias filter. The lowpass filtered input signal,
centered around 1.25 volts, should appear at U2 pin 23
(the input to the A/D converter). The DSP D to A
converter output should appear at U2 pin 2. The
lowpass filtered output signal appears at U8 pin 14.
Finally, the speaker output is driven from U9 pin 8.
❏ 5. If you do not find a short that way, then take your
ohmmeter and go around each chip and check not only
adjacent pins on each IC, but every other pad on the PC
board. Each time you find continuity, check against the
schematic to see if the two points which you found to
be connected are in fact supposed to be connected.
Although this may sound time consuming, it may be the
❏ 15. As of March 1993, of the units that have been
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returned for "warranty service," all but three of the
problems have been defective soldering. The first
exception was a unit which had an IC pin bent under
the chip, not making contact with the socket. The
second exception was a case where a ham had bought
bipolar PROM firmware for both the CW filter and the
LMS algorithm. He had the high byte from the CW
filter installed with the low byte from the LMS
algorithm (the PROMs have to be installed as a pair).
The third non-soldering problem was a PC board
defect. So in every case so far except one, the problems
have been attributable to defects in kit building. We say
this not to impugn anybody’s building skills but to
point out that there have been no defective components
discovered as yet.
If you need a reply to a question, a self-addressed
stamped envelope would be appreciated.
UPS shipping address for returned kits:
David L. Hershberger, W9GR
10373 Pine Flat Way
Nevada City, California 95959-9136
Parcel post shipments (U. S. mail) should be directed to
the P. O. Box address above.
COPYRIGHT NOTICE
The program software/firmware (U3 and U4) supplied
with this digital signal processor is copyright (c)
1992-1993 and all rights are reserved. This
software/firmware may be copied, distributed, and used
for noncommercial purposes only provided that a copy
of this copyright notice is distributed with the
software/firmware. Software/firmware supplied as the
TMS320P15 "multi-program chip" (U1) may not be
copied or distributed to third parties. A license is
required for commercial use of this software/firmware.
Licensing inquiries may be directed to Quantics, P. O.
Box 2163, Nevada City, California 95959-2163.
❏ 16. Although the great majority of kit builders
have completed the W9GR DSP kit successfully,
there have been significant numbers of "warranty"
returns, the vast majority of which are anything but
that. Over 95% of the kits returned for "warranty
service" do not work because of bad soldering. The
warranty covers "defects in materials and
workmanship" of Quantics, and does not cover the
workmanship of the kit builder, over which we have
no control.
❏ 17. We are spending so much time correcting
soldering defects that it is slowing down kit
shipments. Therefore, effective immediately, any kit
returned for "warranty repair" must be
accompanied by a check for $40.00 which is our
"flat rate" for getting defective kits to work and
returning them to you (abuse excepted). If in our
judgment the failure is due to a defect in our
components or workmanship, your $40.00 payment
will be returned to you with the repaired kit. On the
other hand, if the failure is due to improper
assembly or soldering defects, the flat rate fee will be
retained.
LIMITED WARRANTY
This product is warranted to be free of defects in
materials and workmanship for a period of thirty days
from the date of purchase. In the event of notification
within the warranty period of defects in materials or
workmanship, the seller will, upon return of the
product, repair or replace (at its option) the defective
parts. The remedy for breach of this warranty shall be
limited to repair or replacement and shall not
encompass any other damages, including but limited to
loss of profits, special, incidental, consequential or
other similar claims. This warranty does not cover any
damages due to accident, misuse, abuse or negligence
on the part of the purchaser. This warranty does not
cover other equipment or components that a customer
uses in conjunction with this product.
THE SELLER SPECIFICALLY DISCLAIMS
ALL OTHER WARRANTIES, EXPRESSED OR
IMPLIED, INCLUDING BUT NOT LIMITED TO
IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE.
Some states do not allow the limitation or exclusion of
liability for incidental or consequential damages, or the
exclusion of implied warranties, so the above
limitations and exclusions may not apply to you. This
warranty gives you specific legal rights and you may
also have other rights which vary from state to state.
❏ 18. In summary, the warranty covers defects in
components supplied by Quantics (for example PC
board manufacturing flaws). The debugging service,
which is not free, covers kit building errors (for
example soldering defects). This policy supersedes and
clarifies any previous statements.
❏ 19. As of March 1993, the statistics regarding kit
problems are as follows:
Defective soldering:
Chips plugged into sockets incorrectly:
PC board flaws:
Bad parts supplied by Quantics:
42
2
1
0
❏ 20. If you are still unable to resolve the difficulty,
you may either write for assistance or return the unit for
repair. Any returned kit must be accompanied by a
check for $40.00. If in our opinion the problem is
covered by the warranty, then your check will be
returned to you with the kit. The warranty is not
intended to cover defective soldering, so please check
your soldering before returning kits for repair. Support
is handled by correspondence; at the present time we
are not able to provide support via telephone. However,
problem reports, suggestions, comments, and questions
are welcomed and should be directed to:
Thank you for your purchase of the
W9GR Digital Signal Processor!
73, Dave Hershberger, W 9 G R
QUANTICS
P. O. Box 2163
Nevada City, California 95959-2163
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