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OPERATING

AND SERVICE

MANUAL

355C

355D

355E

355F

VHF

ATTENUATOR

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UST 1980

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Model355C/D/E/F

Pa4e

2

GENERAL INFORMATION

This manual contains operating instructions

for

Hewlett-Packard Model 355C, 355D, 355E, and 355F

VHF Attenuators. Included in the manual is the information required to install and test these attenuators.

On the rear cover of this manual, below the manual part number, is a

"Microfiche" part number.

This number may be used to order a 100

x

150 mm (4 x

6 in.) microfilm transparency of the manual.

The microfiche package also includes the latest Manual

Changes supplement as well as all pertinent

Service

Notes.

Models 355D and 355F provide 0 to

120 dB of attenuation manual in

10 dB steps.

The 355C and 355D are attenuators. The 355E and 355F are programmable. The schematic for the Model 355C/D is shown in

Figure 1 and that of the Model 355E/F in

Figure 2.

The attenuator sections consist of resistor pi networks which are switched in or bypassed by microswitches.

In the 355C and 355D the microswitches are actuated by cams (see

Figure

1).

In the

355E and

355F the microswitches are actuated noids (see

Figure 2). The standard by sole-

RF connectors are

BNC type.

In the

355E and 355F power must be continuously applied to the solenoid to actuate the microswitch

(i.e., to insert an attenuator section). Each solenoid draws approximately 0.1A at

15

Vdc.

Specifications

Instrument specifications are listed in

Table 1. These specifications are the performance standards or limits against which the instruments may be tested.

Description

The Hewlett-Packard Model 355C, 355D, 355E, and 355F Attenuators are 50-ohm, coaxial step attenuators usable from dc to

1

GHz.

Models 355C and

3558 provide 0 to

12 dB of attenuation in

1 dB steps.

Warranty

Attenuators are warranted only when they are operated within their specifications, especially power handling capability.

Any attenuators returned to

Hewlett-Packard under warranty will be examined carefully to determine proper use. Be sure to

if

the failure observe the was due following to imcaution.

Table

t.

Specifications

MODELS 355C and

355E

Attenuation Range:

0 to

12

Attenuation steps:

1

dB. dB.

overall

Accuracy:

0.1 dB at 1000

Hz.

0.25 dB, dc to

500 MHz.

0.35 dB, dc to

1000

MHz.

Maximum

SWR

(input and output):

1'2 below

250MHz;

1'3 below 500

MHz;

1'5 below 1000

MHz'

Maximum

Residual

Attenuation:

Less than 0.2b dB to

100

MHz;

Less than

0.75 dB to

500

MHz;

Less than 1.5 dB to

1000

MIIz.

M0DELS

3550 and

355F

Attenuation

Range: 0

Attenuation

Steps:

10 to

120

dB. dB.

Overall

Accuracy: at 1000 Hz, 0 to

120 dB,

10.3 dB;

Below 1000 MHz, 0 to 90 dB,

90 to

120 dB' tg

dB'

t1.5 dB;

MSDE1S

3ESE and

3bbF

switching speed: 6b ms.

Required

Solenoid

Power:

+15 to

+18 Vdc,

U8

A.

M0DELS 355c/E and

3550/F

Frequency Range: dc

Impedance:

50 ohms to

1000

MlIz.

(nominal).

Maximum Power Dissipation: 0.5w, average.

Maximum

Pulse

Voltage: 350

Vpk.

remale'

ffi||:[f*PNC'

35bG and

3bED

3EbE and 3bEF ffili;i'riu3;[tt

Height:

68 mm

,?]".,

]l'trjt;113il:l

(2 1U16

in.)

71 mm

(2 1U16 in.)

Weight: 0.67 kg

(1.5 lb).

v v

\-'" lDimensions are for general information only. If.dimensions are required for building special enclosures. coltact vour

HP office'

Model355C/D/E/F

Page 3

Do not exceed the RF power rating

of

0.5W auerage, or

2450W peak with a maximum pulse width of

200

ps. Do not connect an attenuator

RF input output connector to greater than or

!5

Vdc.

If

the attenuator must be connected to a deuice with a potential gxeater than x5

Vdc, use a blocking capacitor.

Accessories Supplied

The 355E and 355F programmable attenuators are supplied with a

7 pin, male connector (HP

\257-

1037) for the solenoid drive input.

Options

Table

2lists the options available.

INSTALLATION

lnitial

lnspection

Inspect the shipping container for damage.

If

the shipping container or cushioning material is damaged,

it

should be kept until the contents of the shipment have been checked mechanically and elec-

trically.

A procedure for checking electrical performance is given under "Operator's Check"

(see

PERFORMANCE TESTS).

If

the contents of the shipment are incomplete,

if

there is mechanical damage or defect, or

if

the instrument does not pass the electrical performance test, notify the nearest Hewlett-Packard office.

If

the shipping container is damaged, or the cushioning material shows signs of stress, notify the carrier as well as the

Hewlett-Packard

office.

Keep the shipping materials for the carrier's inspection.

Mating Connectors

Mating RF input and output connectors used with the attenuators should be:

Standard:

Type BNC.

Option 001:

Type N.

Option 005:

Type TNC.

For the 3558 and 355F, the solenoid drive connector plug is 7-pin male (HP 1251-1037).

Operating Environment

The operating environment of the instrument should be within the following limitations:

Temperature: 0 to +55'C.

Humidity:

l9SVorelative.

Altitude:

<4570 m (15 000

ft).

Storage and Shipment

Environment.

The instrument should be stored in a clean, dry environment.

The following environmental limitations apply to both storage and shipment:

Temperature:

-40'C to

+75oC

Humidity:

195Vo relative

Altitude:

<7620 m (25 000

ft).

Original Packaging. Containers and materials identical to those used in factory packaging are available through Hewlett-Packard offices.

If

the instrument is being retumed to

Hewlett-Packard for servicing, attach a tag indicating the type of service required, retum address, model number, and

full

serial number.

Also, mark the container FRAGILE to assure careful handling. In any correspondence, refer to the instrument by model number and

full

serial number.

OPERATING

I

NSTRUCTIONS

Do not apply RF power greater than

0.5W auerage, imurn pulse or 2450W peak with a nnatcwidth of

200 ps.

If

these limits are exceeded, the

Attenuator may be damaged.

Either

RF connector may be used as the input or output connector, except in the case driven

ofthe

355D/F from a low impedance source. This is because the leaf switch (Figures 1 and

2) may be closed before the microswitch.opens when the dial is switched from

50 dB to

60 dB. Should this occur, a momentary shorb is placed across the connector, inviting damage to either the microswitch or the signal source. Therefore,

if

the signal source is subject to damage by a short, use the rear most connector for the input.

(The dial or solenoid connector is at the front of the attenuator.) This pads the momentary shorb with

50 dB of isolation. For the 355E and

355F, wire the solenoid drive plug supplied using

Figure 3 as a wiring guide. An un-energized attenuator solenoid section is 0 dB.

(with respect

Apply +15 to

+18

Vdc to pin

H) to energize an attenuator solenoid.

A programming table is also given in

Figure

3.

Page 4

MODELS 355C

AND 355D

Model355C/D/E/F

MODEL

355C

6dB o

l------t

17.61

17.61

2d8 o

3dB o

MODEL 355D

60 dB o l0 dB o

LEAF

SWITCH

20 dB o 30 dB o

NOTES

1.

Microswitches shown in 0 dB position.

2.

Resistances in ohms

e

lno/"|.

3.

Capacitance values lactory€dlusted.

4.

*Asterisk denotes factory selected value.

Figure

1.

Schematic Diagrams, Models 355G and 3550 v

Model355C/D/E/F

-MODELS

355E

AND

355F

Page 5

MODEL

355E td8 s

2dB

3d8

$

S

MODEL

355F

60 d8 s

LEAF

SWITCH

D1

20 dB s

30 dB

S

1.

2.

3.

4.

NOTES

Microsruitches shown in

0 dB position.

Resistances in ohms

l!

1lzYol.

Capacitance values factory-adjusted.

*Asterisk denotes factory selected ralue.

Figure

2.

Schematic Diagrams, Models 355E and

355F

Page 6

Model355C/D/E/F

Table

2.

Attenuator Optiom

Models 355G and

355D

Option

001

option

003

-

Type N input and output connectors.

-

Hfffifl;r1t"H;:rtl?"T

provide panel mountine capability by incorp-

1.

The attenuator shaft is

3116" longer, thereby allowing the instrument shaft to protrude through a

3l\6" panel.

2. Four

6-32 holes are drilled and tapped in the instrument casting to allow the instrument to be mounted to a panel.

3. A 1

314" dial is added. (This dial is larger than that used with the standard Models 355C/D.)

NOTE

Panel drilling detail for rnounting

Option

003 is as follows: l-

1.250

I

k+k-o.soo

l*l

l.-o,uo

@r@T e

0.562

@-d-

0.375

0RtLL

N0.22

DRILL

(FOUR

PLACES)

Option

005

-

Tlpe

TNC input and output connectors.

Models 355E and 355F

Option

007

-

Adds transistor driver protection circuitry as follows:

CoNNECToR: HP

No.

125l-1036

MATING Pl-llG: HP

No. 125l-1037 l25l-10{0 l25l-1041

A ros ll io cs

2dB mdB lD:

HP i,lo. 0491{n4E (4

AldB

ll lo dB

A6 ll oo dB os

Diode: HP No. lgolflA

6

REQID)

NOTE

Pin

H must be positiue with respect to other pins.

\J

(r

Model355C/D/E/F

C

To obtain attenuation settings given below, apply

+15 to

+18

Vdc between Pin

H (common) and pins:

3558 355F

Pins

3558

355F

Pins

1dB

2dB

10 dB

20 dB

A

B

7dB

8dB

70 dB

80 dB

F,A

F,B

3dB

4dB

30 dB

40 dB

C

C,A

9dB

10 dB

90 dB

100 dB

F,C

F,C,A

5dB

6dB

50 dB

60 dB

C,B

F

11 dB

12 dB

110 dB

120 dB

F,C,B

F,CrB,A

Figure

3.

355E and

355F

Solenoid and

Connector

Wiring and Programming

Page 7 s

Page

8 Model SSSClDlElF

OPERATOR'S CHECK

DESCRIPTION:

The attenuator is driven from a 50 ohm signd source at L kHz.

The ou@ut level from the attenuator is detected by a narrow-bandwidth voltmeter

(that is, the SWR meter).

The attenuator and detector range switches are stepped together and the variations in level noted.

This vedfies that each attenuator section is being properly switched and checks the lowfrequency accuracy of the attenuator.

NOTE

The

SWR

Meter used in this check b calibrated for a square-hw detector and therefore the range changes and ercors (read in dB) are twice that indicated by the meter.

HP

65I

B

TEST OSCILLATOR t{P 415E

S'IYR filETER

355C

0R 3550

MANUAL

ATTENUATOR

I

I

I

355E

0R 355F

PROGRAMMABLE

ATTENUATOR s0LEN0l0

DRIVER CIRCUITS

SEE FIGURE

2

PROCEDURE:

1.

2.

3.

4.

Connect equipment as shown above with Attenuator set to

0 dB attenuation.

Set

Test Oscillator to

0.3

Vrms at

1 kHz.

Set the

SWR

Meter input to XTAL

IMPED

LOW and the range to

2 dB (expanded) for

355D or

355F or to

10 dB

(with

0 dB expand) for

355C or 355E. Adjust its bandwidth to the center of the adjustment range. Fine tune oscillator frequency to obtain the maximum meter indication.

Set attenuator and SWR Meter range switch as listed in table next page, and verify that the

S\ilR Meter indicates within the limits shown.

v

Figure

4.

0perator's

Checks

(1 of

2)

Model355C/D/E/F

OPERATOR'S CHECKS

SWR

Meter

Range

(dB)

12

12

12*

74

L4

L4 l4*

10

10

10

10

10*

Attenuation

(dB)

3

4

,

1

0

355C And 355E

Min.

Meter lndication

(dB)

Actual

Max.

Set to

0.0

0.45

0.95

1.45

1.95

0.55

1.05

1.55

2.05

7

8

9

5

6

0.45

0.95

1.45

1.95

0.45

0.55

1.05

1.55

2.05

0.55

10

11 t2

0.95

t.45

1.95

1.05

1.55

2.05

SIUR Meter

Bange (dB)

Attenuation

(dB)

3550

And

355F

Meter lndication

(dB)

Min.

Actual

Max.

2

6

L2

16

,t

0

10

20

30

40

1.35

0.35

1.35

0.35

Set to

0.5

26

32

36

42

46

50

60

70

80

90

1.35

0.35

1.35

0.35

1.35

52

56

62

100

110

L20

0.35

1.35

0.35

*Adjust range by

2 dB, if needed to obtain an on-scale indication.

1.65

0.65

1.65

0.65

1.65

0.65

1.65

0.65

1.65

0.65

1.65

0.65

Figure

4.

0perator's

Checks

(2of

2l

Page 9

Page 10

Model 355C/D/E/F,

OPERATOR'S CHECK

The Operator's Check (Figure 4) is supplied to allow the operator to make a quick check of the attenuator prior to use or

if

a failure is suspected.

PERFORMANCE TESTS

The attenuator can be tested to the accuracy of the specifications in

Table 1 with an

Automatic Network Analyzer or equivalent equipment of suitable accuracy.

If an

Automatic Network

Analyzer is available, test the attenuator using the procedures in the analyzer's operating manual.

The 355E and

355F attenuators must be programmed by a suitable circuit to provide the various values of attenuation

(see Figure 3).

If

any parts not listed in

Table 3 need replacement, return the instrument to

Hewlett-Paekard.

To order a part listed in the replaceable parts table, quote the Hewlett-Packard part n 'mber with check digit (CD), indicate the quantity required, and address the order to the nearest Hewlett-Packard office.

NOTE

Within the

USA,

it

is better to order direct-

Iy from the HP Parts Center in information and fornts

Mail

Order

System".

Mt.

View,

&lifornia.

Ash your nearest HP office

for

for the "Direct

SERVICE

Troubleshooting

Tloubleshooting consists tor's

Check shown of performing the

Operain

Figure

4. If

the instrument does not perform ment within limits, return the instruto

Hewlett-Packard.

ADJUSTMENTS

The attenuators have no internal adjustments and should uator not be opened.

If

defective, return the attento the nearest

Hewlett-Packard office for repair.

The solenoids in the 3558 and 355F haue been precisety adjusted at th,e factory.

No attempt should be rnade to replace them eJccept by factory approued seruice representatiues. The operation

of

the attenuators will be unreliable if plungers are not kept with their proper solenoids.

Do not interchange or

"Eutap" thern.

REPLACEABLE PARTS

Table 3 lists the replaceable parts which are the only parts that can be replaced without access to the interior of the attenuator.

Due to special sembly, fixtures necessary

for

asdo

NOT attempt to replace any parts not listed in

Table

3.

If

the instrument is opened, the

warranty

is uoid.

Table

3.

Replaceable Parts

Dial

Assembly

355C lCD

Glide (feet) 4 each

Dial

Assembly

.

HP

HP

0403-0026

I

7

355A-40G

|

0

(Option

003).

HP

00355-00001

| 5

Glide (reet)

4 each

. . :u:0.

HP

040s-0026

I

,

Dial

Assembly

Dial Assembly

(Option

HP

355A-40H

|

8

003).

HP

00355-00002

| 6

.

3558 and

355F

Glide (feet) 4 each

Connector,

7 pin

HP

0403-0026

(male)

HP

1251-1037

I

I

6

|

9

\,./

I

\-

U

CERTIFICATION

Hewlett-P-ockard. factory. certifies thot this prod,uct-rnet.its published specif ications at the time of shiprnent

Hewlett-Packardfurther certifies thatits colibrotion

Bureau of Standards, to the extent ollnwed by the Bureou's

Internationol

Standoids Organizotion mernbers.

m"o"ur"*"it" ore colibrotion facility, traceoble and to to the united the calibration

States from facilities the

Notional of othir

WARRANTY

This Hewlett-Packard instrument product is warranted against defects in material and workmanship for year from date of shipment.

During the warranty replace products which prove to be defective.

period, Hewlett-Packard Company wiU, at its a period of one option, eitirer repair or

For warranty service or rep_air, thie product must be returned to a service shipping charges to HP and HP shall pay shipping charges to_return the product to ehipping charges, dutiea, and taxes for products returned to HP from facility designated by HP. Buyer shall prepay

Buyer. Ho*erner, Buyer shall pay another country.

ail

HP warrante that its software and firmware deeignated by

HP for use with an inetrument will execute its programming inetructions when properly inetalled on that inetrument. HP does not warrant that the software, or firnware will be uninterrupted or error free.

operation of the ilnetiument, oi

LIMITATION

OF WARRANTY

The foregoing-warranty ehall not apply to defects resulting from improper or inadequate maintenance

Buyer-eupplied software or interfacing, unauthorized modification or misuee, operation outside specifications for the product, or improper site preparation or maintenance.

ofthe by

Buyer, environmental

NO

OTHER WARRANTY IS

EXPRESSED OR

IMPLIED.

HP SPECIFICALLY

WARRANTIES

OF

MERCHANTABILITY AND

FITNESS FOR

A PARTICULAR

DISCLAIMS

PURPOSE.

THE

IMPLIED

EXCLUSIVE REUEDIES

THE REMEDIES PROVIDED

HEREIN

ARE BUYER'S SOLE AND EXCLUSIVE

REMEDIES. HP SHALL NOT BE

LIABLE

FOR

ANY DITECT,

INDIRECT, SPECIAL, INCIDENTAL,

OR CONSEQUENTIAL

DAMAGES,

WHETHER BASED ON CONTRACT, TORT. OR

ANY

OTT{ER LEGAL

THEORY.

ASSISTANCE

Prod-uct rnointenonce agreements products.

and other custonrcr assistance agrcements are auoilable for Hewlett-packord

HEWLETT.PACKARD SERVICE

OFFICES

To obtain servicing information, contact the nearest Hewlett-Packard Sales and

Service Office contact the nearest regional office lieted below.

in

HP

Catalog, or

UIIITEll

STATES

NO.

CALIFORNIA (San Franciaco Area)

333 la3ue Ave.

Mt. View, CA

94043

SO-

CALIFORNIA ([os

Angelee Area)

5{(X}

West Roreqane Blvd.

Iawndale,

CA 90260

GEORGIA

450 Interstate N. Parkway

Atlanta,

GA

30348

ILLINOIS

5201

Tollview Dr.

Rolling Meadowa, IL

60008

NEW JERSEY

W.

120 Century Rd.

Paramua, NJ

0?652

AUSTRATIA

Hewlett-Packard Auatralia Ltd.

3l-41 Joseph Street

Blackburn, Victoria

3130

CAIIAllA

Hewlett-Packard (Canada) Ltd.

6877 Goreway

Drive

Misaieaauga,

Ontario

Canada I"4V lM8

ITAIY

Hewlett-Packard

Italiana

S.p.A.

Via G. Di

Vittorio,9

20O63 Cernueco

Sul Naviglio

(MI)

FEAIICE

Hewlett-Packard France

Quartier de

Courtabcuf

Boite Poetale No. 6

F-91401 Oreay Cedex

GERtIIAlI

FEllEBAT

REPUEtIC

Hewlett-Packard GmbH

Vertriebszentrale

Bernerstrasse ll?

Frankfurt

Poatfach

560 140

D-6000

Franlfurt

56

IIETHERTAlIOS

Hewlett-Packard Benelux N.V.

Van Heuven D@dhartlaan l2l

P.O. Bor

667

NLAmatelveen

1134 ulilTE0 KrtG00ttt

Hewleti-Packard Ltd.

King Street Iane

GB-Winnerah, Wokingham

Bere, RGrr 5AR

AFBICA, ASIA, CEIITRAT AilD

SOUTIIAilIERICA

Hewlett.Packatd

Intarco!tinental

3200

Hillview

Avenue

Palo

Alto, CA

94304

HP

Part No. 00355-90045

Microfiche

Part No. 00355-90046

ftE'FEY-'fJJ

Printed in U.S.A.