EIP Phasematrix 451 schematic

TM 11-6625-3031-14

.

TECHNICAL MANUAL

OPERATOR’S, ORGANIZATIONAL,

DIRECT SUPPORT,

AND

GENERAL SUPPORT MAINTENANCE MANUAL

COUNTER, PULSE, ELECTRONIC

TD-1338(V)1/USM

(NSN 6625-01-120-7832)

HEADQUARTERS, DEPARTMENT OF THE ARMY

6 MAY 1983

SAFETY STEPS TO FOLLOW IF SOMEONE

IS THE VICTIM OF ELECTRICAL SHOCK

DO NOT TRY TO PULL OR GRAB THE INDI-

VIDUAL

IF POSSIBLE, TURN OFF THE ELECTRICAL
POWER

IF YOU CANNOT TURN OFF THE ELECTRICAL

POWER, PULL, PUSH, OR LIFT THE PERSON
TO SAFETY USING A WOODEN POLE OR A ROPE
OR SOME OTHER INSULATING MATERIAL

SEND FOR HELP AS SOON AS POSSIBLE

AFTER THE INJURED PERSON IS FREE OF CON­TACT WITH THE SOURCE OF ELECTRICAL

SHOCK, MOVE THE PERSON A SHORT

DISTANCE AWAY AND IMMEDIATELY START

ARTIFICIAL RESUSCITATION

TM 11-6625-3031-14

TECHNICAL MANUAL

NO. 11-6625-3031-14

REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS

You can help improve this manual.
you know of a way to improve the procedures, please let us know.
Mail your letter,

tions and Blank Forms),

this manual direct to:
Electronics Command and Fort Monmouth, ATTN:
Fort Monmouth, NJ 07703.

DEPARTMENT OF THE ARMY

WASHINGTON, D.C. 6 May 1983

OPERATOR’S,
AND GENERAL SUPPORT MAINTENANCE MANUAL

ORGANIZATIONAL, DIRECT SUPPORT

FOR

COUNTER, PULSE, ELECTRONIC

TD-1338(V)1/USM

(NSN 6625-01-120-7832)

If you find any mistakes or if

DA Form 2028 (Recommended Changes to Publica-

or DA Form 2028-2 located in the back of
Commander, US Army Communications-

DRSEL-ME-MP,

HEADQUARTERS

Chapter

Section I.

In either case,

INTRODUCTION

1.

General Information . . . . . . . . . . . . . . .

Scope. . . . . . . . . . . . . . . . . . . . 1-1

Reports of maintenance forms, records and

reports. . . . . . . . . . . . . . . . . . . . . 1-2

Administrative storage . . . . . . . . . . . . . 1-3

Destruction of Army electronics materiel. . . . . 1-4

Reporting equipment improvement recommendations

(EIR'

S

). . . . . . . . . . . . . . . . . . . . . 1-5

Warranty information . . . . . . . . . . . . . . 1-6

II.

Equipment Description . . . . . . . . . . . . . .

Equipment characteristics, capabilities and

features . . . . . . . . . . . . . . . . . . . . 1-7

Equipment data . . . . . . . . . . . . . . . . . 1-8

III.

Technical Principles of Operation . . . . . . . .

Counter functional operation . . . . . . . . . . 1-9

a reply will be furnished direct to you.

TABLE OF CONTENTS

Para

Page

1-1
1-1

1-1
1-1
1-1

1-1
1-1

1-2

1-2
1-2
1-4
1-4

i

TM 11-6625-3031-14

TABLE OF CONTENTS - Continued

Chapter

Section I.

2.

II.

III.

Para

Basic counter A1 . . . . . . . . . . . . . ...1-10

Converter A2 . . . . . . . . . . . . . . . . . . 1-11

OPERATING INSTRUCTIONS
Description and Use of Operator’s Controls and

Indicators . . . . . . . . . . . . . . . . . . .

Front-panel controls, connectors and

indicators . . . . . . . . . . . . . . . . . . .

Rear-panel controls and connectors. . . . . . . .

Preventive Maintenance Checks and Services . . .

General instructions. . . . . . . . . . . . . . .

PMCS procedures. . . . . . . . . . . . . . . . .

Cleaning instructions . . . . . . . . . . . . . .

Operation Under Usual Conditions . . . . . . . .

Assembly and preparation for use . . . . . . . .

Operation as stand-alone instrument . . . . . . .

Externally enabled operation . . . . . . . . . .

Pulse profile measurements. . . . . . . . . . . .

Dynamic characteristics of time varying signals .

Multiple pulse signal measurements . . . . . . .

Timing considerations . . . . . . . . . . . . . .

Accuracy . . . . . . . . . . . . . . . . . . . .

Techniques for improving accuracy . . . . . . . .

Operation using General Purpose Interface Bus . .

2-1
2-2

2-3
2-4
2-5

2-6

2-7

2-8
2-9
2-10
2-11
2-12

2-13
2-14
2-15

Page

1-6
1-8

2-1

2-1
2-1
2-5
2-5
2-5
2-6
2-7
2-7
2-8

2-10
2-10
2-11
2-11
2-11
2-12
2-13
2-13

Chapter

Section I. Lubrication . . . . . . . . . . . . . .

III. Maintenance Procedures . . . . . . . . . . . . . . . . .

Chapter

Section I.

III.

OPERATOR AND ORGANIZATIONAL

3.

II.

Troubleshooting Procedures . . . . . . . . . .

Introduction . . . . . . . . . . . . . . . . . . . . . . .

Inspection. . . . . . . . . . . . . . . . . . . . . . . .

Cleaning . . . . . . . . . . . . . . . . . . . . . . . . .

Replacement . . . . . . . . . . . . . . . . . . . . . . .

Test. . . . . . . . . . . . . . . . . . . . . . . . .

4.

DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
Repair Parts, Special Tools; Test Measurement,
and Diagnostic Equipment (TMDE); and Support

Equipment. . . . . . . . . . . . . . . . . . . . . . . . .

Common tools and equipment . . . . . . . . . .

Special tools, TMDE,

Repair parts . . . . . . . . . . . . . . . . . . . . . .

II.

Service Upon Receipt . . . . . . . . . . . . .

Troubleshooting . . . . . . . . . . . . . . . . . . . . .

Introduction . . . . . . . . . . . . . . . . . . .

Reference diagrams . . . . . . . . . . . . . .

IV.

Maintenance Procedures . . . . . . . . . . . .

Disassembly, replacement, and reassembly . . .

Adjustments. . . . . . . . . . . . . . . . . .

Performance test . . . . . . . . . . . . . . . . .

and support equipment . .

MAINTENANCE

3-4
3-5
3-6
3-7
3-8

4-1
4-2
4-3

4-5
4-6

4-7
4-8
4-9

3-1

3-1
3-3

3-3
3-3
3-3

3-3

3-3

4-1
4-1
4-1
4-1
4-1
4-1
4-1
4-2
4-17

4-17
4-20
4-28

ii

TABLE OF CONTENTS - Continued

TM 11-6625-3031-14

Section

Preparation for Storage or Shipment . . . . . . .

V.

Preparation of equipment. . . . . . . . . . . . . 4-10

Packing instructions. . . . . . . . . . . . . . . 4-11

Appendix A. REFERENCES. . . . . . . . . . . . . . . . . . . .

Appendix B.

Appendix C.

MAINTENANCE ALLOCATION . . . . . . . . . . . . .

COMPONENTS OF END ITEM AND BASIC ISSUE

ITEMS LISTS. . . . . . . . . . . . . . . . . . .

Appendix D.

Appendix E.

ADDITIONAL AUTHORIZATION LIST . . . . . . . . . .

EXPENDABLE SUPPLIES AND MATERIALS LIST . . . . .

Para

Page

4-33
4-33
4-33

A-1

B-1

C-1

D-1

E-1

iii

TM 11-6625-3031-14

LlST OF ILLUSTRATIONS

Figure

1-1
1-2
1-3
1-4

2-1

2-2
2-3
2-4
2-5
2-6
2-7
2-8

4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8

4-9
4-10
4-11
4-12

Title

Counter,
Counter,
Basic Counter A1,

Converter A2, Functional Block Diagram . . . . . . . . . . . . . . 1-9

Counter Front Panel. . . . . . . . . . . . . . . . . . . . . . . .2-1

Counter Rear Panel. . . . . . . . . . . . . . . . . . . . . . . .2-4

Pulse Profile Measurement Test Setup . . . . . . . . . . . . . . . 2-10

Pulse Profile Measurement . . . . . . . . . . . . . . . . . . . . 2-10

Time Varying Signal Measurement Test Setup . . . . . . . . . . . . 2-11

Internal Timing Delays . . . . . . . . . . . . . . . . . . . . . . 2-12

GPIB Capabilities and Structure . . . . . . . . . . . . . . . . . 2-15

GPIB IEEE STD 488/1975 ADDRESS SWITCH Positions . . . . . . . . . 2-16

Subassembly and Cable Locations . . . . . . . . . . . . . . . . . 4-3

Counter Interconnect A100, Connector and Switch Locations . . . . 4-17

Counter, Partial Exploded View . . . . . . . . . . . . . . . . . . 4-18

Adjustment Locations. . . . . . . . . . . . . . . . . . . . . . . 4-21

Pulse Generator Output . . . . . . . . . . . . . . . . . . . . . . 4-23

YIG Control A202, Adjustment and Test Point Locations . . . . . . 4-24

Detected Modulation and 20 kHz Reference Pulse Timing . . . . . . 4-24

Converter Sequencer A203, Adjustment and Test Point

Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-26

Return Loss Measurement Setup . . . . . . . . . . . . . . . . . . 4-26

Return Loss Measurement Waveform . . . . . . . . . . . . . . . . . 4-27

Typical Attenuator Control Ramp Offset . . . . . . . . . . . . . . 4-27

Comb Line . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-27

Pulse, Electronic TD-1338(V)1/USM . . . . . . . . . . . . 1-0

Functional Block Diagram. . . . . . . . . . . . . . . . . 1-5

Functional Block Diagram . . . . . . . . . . . . 1-7

Page

FO-1
FO-2

FO-3A

FO-3B

FO-4A

FO-4B

FO-5A

FO-5B

FO-6A

FO-6B

FO-7A

FO-7B

FO-8A

FO-8B
FO-9A
FO-9B
FO-10A

FO-10B

iv

Counter Interconnection Schematic Diagram
Interconnection Diagram,
Component Locator Counter Interconnect (A100)
Schematic Diagram Counter Interconnect (A100)
Component Locator and Descriptive Information Count Chain Control (A102)

Schematic Diagram Count Chain Control (A102)

Component Locator and Descriptive Information Count Chain (A103)

Schematic Diagram Count Chain (A103)
Component Locator and Descriptive Information Control (A104)
Schematic Diagram Control (A104)
Component Locator and Descriptive Information Gate Generator (A105)
Schematic Diagram Gate Generator (A105)
Component Locator and Descriptive Information High Frequency (A106)
Schematic Diagram High Frequency (A106)
Component Locator and Descriptive Information Power Supply (A107)
Schematic Diagram Power Supply (A107)
Component Locator and Descriptive Information Reference Oscillator
Buffer (A108)
Schematic Diagram Reference Oscillator Buffer (A108)

Detailed Technical Schematic

TM 11-6625-3031-14

Figure

FO-11A
FO-11B
FO-12A
FO-12B

FO-13A
FO-13B
FO-14A
FO-14B
FO-15A
FO-15B
FO-16A
FO-16B

LIST OF ILLUSTRATIONS

Title

Component Locator and Descriptive Information Display (A110)
Schematic Diagram Display (A110)
Component Locator Converter Interconnect (A200)
Schematic Diagram Converter Interconnect (A200)
Component Locator and Descriptive Information Source/Amplifier (A201)
Schematic Diagram Source/Amplifier (A201)
Component Locator and Descriptive Information Yig Control (A202)

Schematic Diagram Yig Control (A202)
Component Locator and Descriptive Information Converter Sequencer (A203)
Schematic Diagram Converter Sequencer (A203)

Component Locator and Descriptive Information IF Processor (A204)

Schematic Diagram IF Processor (A204)

(Continued)

Table

1-1
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9

3-1
4-1
4-2
4-3
4-4

4-5
4-6

4-7

LIST OF TABLES

Title

Specifications. . . . . . . . . . . . . . . . . . . . . . . . . .

Front-panel Controls, Connectors and Indicators . . . . . . . . .

Rear-panel Controls and Connectors . . . . . . . . . . . . . . . .

Operator Preventive Maintenance Checks and Services . . . . . . .

Counter GPIB Capability Identification Codes . . . . . . . . . . .

GPIB IEEE STD 488/1975 Connector Pin Assignments . . . . . . . . .

On Line and Off Line ADDRESS SWITCH Settings . . . . . . . . . . .

ADDRESS SWITCH Settings vs ASCII Characters . . . . . . . . . . .

Programming Summary. . . . . . . . . . . . . . . . . . . . . . . .

Typical Program Using Hewlett-Packard 9815 Calculator as

Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operator and Organizational Troubleshooting . . . . . . . . . . .

Symptom Index . . . . . . . . . . . . . . . . . . . . . . . . . .

Direct Support and General Support Troubleshooting . . . . . . . .

Power Supply Voltages and Adjustments . . . . . . . . . . . . . .

Band B Response Tests . . . . . . . . . . . . . . . . . . . . . .

Preset Frequency Tests . . . . . . . . . . . . . . . . . . . . . .

Control Sequence. . . . . . . . . . . . . . . . . , . . . . . , .

Converter Sequence Functions . . . . . . . . . . . . . . . . . . .

Page

1-1
2-1
2-5
2-6
2-14
2-16

2-17

2-18

2-20

2-26

3-1
4-2
4-4
4-22
4-29
4-31

4-45
4-65

v

TM 11-6625-3031-14

1-0

Figure 1-1.

Counter, Pulse, Electronic TD-1338(V)1/USM

CHAPTER 1

INTRODUCTION

Section I. GENERAL INFORMATION

TM 11-6625-3031-14

1-1.

tion and maintenance of Counter, Pulse,

Electronic TD-1338(V)1/USM. Throughout

this manual it is referred to as the

counter.

measure the frequency of cw, pulse­modulated, or frequency-modulated
microwave signals between 300 MHz and

18 GHz.
as 100 nanoseconds, with a maximum
pulse repetition frequency of 2.5 MHz.
Peak-to-peak deviation of FM signals
may be as great as 40 MHz at 10 MHz

modulation rates.

1-2.
Records and Reports.

Unsatisfactory Equipment.
of the Army forms and procedures used

for equipment maintenance will be
those prescribed by TM 38-750, The

Army Maintenance Management System

(Army) .
AFM 66-1 for maintenance reporting and
TO 00-35D54 for unsatisfactory equip­ment reporting.

Deficiencies.
SF 364 (Report of Discrepancy (ROD)) as
prescribed in AR 735-11-2/DLAR 4140.55/

NAVMATINST 4355.73/AFR 400-54/MCO

4430.3E.

(DISREP) (SF 361). Fill out and forward
Discrepancy in Shipment Report (DISREP)

(SF 361) as prescribed in AR 55-38/
NAVSUPINST 4610.33B/AFR 75-18/MCO

P4610.19C/DLAR 4500.15.

Scope.

a. This technical manual covers opera-

b. The counter (fig. 1-1) is used to

Pulse widths can be as narrow

Reports of Maintenance Forms,

a. Reports of Maintenance and

Department

Air Force personnel will use

b. Report of Packaging and Handling

Fill out and forward

c. Discrepancy in Shipment Record

1-3.

issued to and used by Army activities

will have preventive maintenance per-

formed in accordance with the PMCS
charts before storing.
the equipment from administrative
storage, the PMCS should be performed
to assure operational readiness.

1-4.

Materiel.

materiel to prevent enemy use shall be

in accordance with TM 750-244-2.

1-5.

Recommendations (EIR’s).

let us know.
user,
what you don’t like about your equip­ment.

the design or performance.
SF 368 (Quality Deficiency Report).
Mail it to:
Communications-Electronics Command and
Fort Monmouth, ATTN: DRSEL-ME-MP,
Fort Monmouth, New Jersey 07703. We’ll
send you a reply.

1-6.

Microwave, Inc. for 12 months. It

starts on the date, found in block 23,

DA Form 2408-9, in the logbook.
all defects in material or workmanship

to your supervisor, who will take appro­priate action through your organiza­tional maintenance shop.

Administrative Storage.

Administrative storage of equipment

When removing

Destruction of Army Electronics

Destruction of Army electronics

Reporting Equipment Improvement

If your counter needs improvement,

Send us an EIR. You, the

are the only one who can tell us

Let us know why you don’t like

Put it on an

Commander, US Army

Warranty Information.

The counter is warranted by EIP

Report

1-1

TM 11-6625-3031-14

Section II. EQUIPMENT DESCRIPTION

1-7.

Equipment Characteristics, Capa-

bilities and Features.

The counter is a portable test
instrument usable as either self­contained frequency measurement or

monitoring indicator, or as part of a

programmable automatic test equipment

(ATE) system.
readout of frequency from 300
through 18 MHz.

It provides a direct

MHZ

Capabilities and

features include:

a. Measures pulse-modulated microwave

signals.

b. Measures frequency-modulated

microwave signals.

c.

Measures cw microwave signals.

d. Front panel self-test of digital

display.

Table 1-1. Specifications

Frequency Range:

Band A

e. Front panel self-test of internal

circuits.

f. Automatic and selectable resolution

of—readout display.

g. Overload protection built in at

input connector.

h.

Simple change to cover different

power line voltages.

i. Front-panel selection of frequency

scanning limits.

j. Comparable with IEEE STD 488

General Purpose Interface Bus (GPIB).

1-8.

Equipment Data.

Table 1-1 lists the electrical
and physical characteristics of the
counter.

300 MHz to 950 MHz

Band B

Pulse Characteristics:

Pulse width
Pulse repetition frequency

Accuracy:

CW or pulse > 100 µsec
Pulse < 100 µsec

Averaging Error (kHz rms):

100 µsec gate

1 msec gate

Gate error (max)

925 MHz to 18 GHz

100 nsec min, measured at 3-dB points

Minimum 50 Hz or 0 Hz, rear panel

selectable. Maximum 2.5 MHz. Minimum
time between pulses 300 nsec.

Time base accuracy ± 1 count
Time base accuracy ± averaging error

± gate error

Band A Band B

NOTE

PW =

pulse width in µsec

1-2

TM 11-6625-3031-14

Table 1-1.

Time Base:

Crystal frequency
Stability:

Aging rate
Temperature
Line voltage

Sensitivity

Input Impedance

Connector Types

Maximum Input Peak Level:

Operating
Burnout level

Specifications - Continued

Temperature compensated crystal
oscillator

(TCXO)

10 MHz

<|3 X 10
<|2 X 10

<|1 X 10

-7

|

per month

-6

|

, 0 to 50°C

-7

|

for ± 10% change

Band A

300

- 950 MHz:

-10 dBm peak

50 ohms nominal

BNC

+10 dBm
+27 dBm

Band B

925 MHz - 10 GHz:

-10 dBm peak
10 GHz - 18 GHz:

-5 dBm peak

50 ohms nominal

N (precision)

+10 dBm
+30 dBm

Reading Time (sec):

100 µsec gate

1 msec gate

Display

Band B Minimum FM Tolerance:

CW

Pulse

Frequency profile

400

(PW) (PRF)

4000

(PW)(PRF)

100

(PW) (PRF)

1000

(PW) (PRF)

NOTE

PW =
PRF =

pulse width in µsec

pulse repetition frequency

in Hertz

7-digit light emitting diode (LED)
Fixed decimal point

Leading zero suppression

40 MHz p-p deviation for modulation
rates dc to 10 MHz

Without input inhibit:

20 MHz maximum

frequency shift across pulse

With input inhibit:

20 MHz maximum

frequency shift during input inhibit

pulse

1-3

TM 11-6625-3031-14

Table 1-1.

Specifications - Continued

Band B Acquisition Time:

PRF > 100 H

Z

PRF < 100 Hz

Resolution

General Purpose Interface Bus (GPIB)

Power

Operating Temperature
Warm up Time
Weight

Dimensions (inches)

100 msec + 50 msec/GHz
100 msec +

sec/GHz

10 kHz, 100 kHz, 1 MHz

IEEE Standard Digital Interface for
Programmable Instrumentation, IEEE
STD 488-1975

115 or 230 Vac ± 10%, 50/60 Hz;
115 Vac ± 10%, 400 Hz; single phase;
100 watts nominal

0-

50°C

None Required

30 lb

3.5 H x 16.75 W x 19.0 D

Section Ill. TECHNICAL PRINCIPLES OF OPERATION

1-9.

Counter Functional Operation.

(Fig. 1-2.)

a. The counter automatically measures
and displays the frequency of cw or
pulse-modulated signals from 300 MHz
through 18 GHz. With accessory equip-

ment,

the counter can make dynamic

frequency measurements; measurement

windows as narrow as 20 nanoseconds are

possible.

Two primary input connectors
on the front panel, BAND A 300 - 950 MHz
and BAND B 925 MHz - 18 GHz, are used to
connect the counter to the external fre­quency source.

An auxiliary INPUT
INHIBIT connector on the rear panel can
be used to control the time during
which an actual reading is made.

Con­trol of the counter can be accomplished
by front-panel switches or by a General
Purpose Interface Bus (GPIB) from an
external GPIB controller.

The output
of the counter is displayed on a 7­digit, fixed decimal, light emitting
diode (LED) display and can be trans­mitted through the GPIB for other

purposes.
controlled by Reference Oscillator Buf­fer A108 with outputs to Basic Counter

Al and Converter A2; a third output is

connected to a rear-panel 10 MHz OUTPUT
connector.

divide-by-four circuit in Prescaler

A109, whose output is directed to Basic

Counter A1 through Dual Delay Line

A116.

counted in the basic counter for either
a 400 microsecond or 4 millisecond
period to obtain 10 kHz resolution read­out on Display A110.
in A1 is enabled by the input signal and
is open only when a signal is present.

verter A2, converted to an IF signal by
heterodyning the input signal against a

200 MHz harmonic,
through Delay Line A112.
gate in A1 is enabled by the Input
signal and is open only when a signal
is present.
inversely proportional to the measurement

Accuracy of the counter is

Band A signals are fed into a

b.

The divide-by-four frequency is

The counter gate

Band B signals are fed into Con-

c.

and directed to A1

The counter

In A1, resolution is

1-4

Figure 1-2.

1-5

TM 11-6625-3031-14

TM 11-6625-3031-14

time.

For example:

a 1 microsecond

gate time will give 1 MHz resolution.

To get 10 kHz resolution, the counter

threshold comes from Prescaler A109

while the Band B threshold comes from

I.F. Processor A204 in Converter A2.
automatically averages as many input
pulses as necessary to obtain a total
gate time of 100 microseconds or 1 mil­lisecond.

The required number of

pulses is a function of input pulse

width.

The intermediate frequency from
A2 is processed and counted in A1 and
displayed on A110.

d.

Three rear-panel connectors provide

10–MHz, SIGNAL THRESHOLD, and GATE OUT-

PUTS .

The 10 MHz OUTPUT is a service
convenience for adjusting the tempera­ture compensated crystal oscillator

(TCXO) on Reference Oscillator Buffer

A108.

The other two signal outputs may

be used for dynamic frequency measure­ments such as pulse profile measurements
or time varying signal measurements.

e.

Power Supply A107 provides +5,

-5.2, +12,
counter circuits.

-12, and +18 volts dc for the
The +18 Vdc output is

unregulated; the other four voltages are
regulated.

processed into the range below 360 MH
and applied to the 400 MHz decade, the

frequency of the signal is determined by
accumulating the number of signal cycles
occurring within a precisely determined

time interval (gate). The gate period

is dependent on the 200 MHz reference

frequency.

gates are 100 microseconds and 1 milli-

second for Band B, or 400 microseconds
and 4 milliseconds for Band A. In order

to measure narrow pulses to a resolution

of 10 kHz, it is necessary to add the
number of cycles counted in each of a

large number of pulses until the

required total time interval is
obtained.

precision interval gate. This function

is considerably more difficult for
pulsed signals than it is for cw sig­nals,

the overall accuracy of the counter

1-10.

Basic Counter A1.

(Fig. 1-3.)

depends.

it supplies a gate to A106 only when an

a. Input signals from either the low

range (300 -

(925 MHz -

950 MHz) or high range

18 GHz) sources, or both,
are applied to the signal processor
circuits on High Frequency Circuit

Card A106.

The signal from Prescaler

input signal is present, and it accumu­lates the total time of gate application
for periods of either 100 microseconds
or 1 millisecond for Band B, or either
400 microseconds or 4 milliseconds for
Band A.

A109 is the BAND A input frequency,
divided by four (f/4). The signal

from I.F. Processor A204 is the BAND B
input frequency minus the reference

frequency identified as the converter
IF signal.

Selection of which signal

to display is controlled by the front
panel BAND selection switches or by
GPIB selection.

Only one of the signal

inputs can be displayed even though
both may be connected to the counter.
The f/4 and the IF signal inputs are

360 MHz or lower and are directed to the

400 MHz decade circuits on A106.

Two threshold (Band A and/or

b.

Band B) control levels are applied to

Gate Generator A105 to provide a gate

output to the 400 MHz decade through

the gate calibrator.

The Band A

requires that the gate begin after the
signal is present at A106 and to end
before the end of signal. This is done
by generating a gate approximately 30
nanoseconds shorter than the RF signal
start as determined by the associated
Band A or Band B threshold level.
arrival time at A106 of the converter
IF or the prescaler f/4 signal is con-

trolled by delay lines in A116, in
series with the signals, so that the
gate will fall entirely within the sig­nal pulse application.

counting clock pulses when the gate is
open until a total period of 100 micro-

seconds or 1 millisecond for Band B, or

400 microseconds or 4 milliseconds for

When an input signal has been

c.

Z

Total time intervals of the

d. Gate Generator A105 provides a

and it is on this function that

A105 performs two functions;

e. The first function or operation

The

f. The second function is done by

1-6

Figure 1-3.

1-7

TM 11-6625-3031-14

TM 11-6625-3031-14

Band A, is accumulated.
that each gate opening is for an exact
integral number of clock pulses.

MHz clock is used, causing the gate

width to increase in 5 nanosecond steps

until a total of 20,000 steps for

100 microseconds, 80,000 steps for

400 microseconds, 200,000 steps for

1 millisecond, or 800,000 steps for

4 milliseconds is accumulated.

g. The signal passes through the
counter gate and is accumulated in the
counting-chain first decade, the 400

MHz decade on A106.

(f/10) of the 400 MHz decade is fed to
the storage unit through the 6-decade
count chain of A103. The storage unit

on A103 holds all of the digital infor­mation from the previous reading.
put from the storage unit is fed to the
display multiplexer which is controlled
by count chain control circuits on the
Count Chain Control A102.

h. Output of the display multiplexer
on A102 is fed to Display A110.
mounted on the front panel along with
LEVEL, LOCK, and GATE status indicators.
The front-panel REMOTE indicator is used
with GPIB controller operations.
all control of the counter is performed
by Control Circuit Card A104. Front­panel selection switching is routed to
A104 through GPIB Remote/Local Circuit
Card AM121.
REMOTE mode of operation, front-panel
controls and switches are inoperative

except for the SAMPLE RATE control, and
then only under certain programming
instructions from the GPIB controller.

1-11.

input microwave frequencies down to
frequencies between 100 and 360 MHz.

Translation is done by mixing the input

frequencies with a reference frequency

to produce, by heterodyne action, an
amplified intermediate frequency.
IF is then fed to A106 through Delay
Line A112 for counting and processing in
Basic Counter A1.

b. Generation of the heterodyning ref-

erence frequency starts by generating a

Converter A2.

a. Converter A2 translates the Band B

When the counter is in the

This requires

A 200

The signal output

Out-

A110 is

Over-

(Fig. 1-4.)

The

200 MHz reference signal in Source/

Amplifier A201. The 200 MHz reference

in A201 is generated by an L-C oscilla-

tor phase-locked to 10 MHz from Refer­ence Oscillator Buffer A108.
MHz outputs from A201 are directed to
YIG (Yttrium-Iron-Garnet) Comb Generator
A207 and to Gate Generator A105 in
Basic Counter A1.
section on A201 amplifies the 200 MHz
signal before it is applied to A207.
The 200 MHz output to A105 is used to
generate a Band B gate or may be used
for a TEST 200 MHz self-test.

harmonic, frequency is generated in YIG
Comb Generator A207 by taking the 200
MHz signal from A201 and converting it
to a train of narrow pulses containing
all harmonics of 200 MHz up to 18 GHz.
This conversion is done by the YIG comb
generator and a two-stage YIG filter,

which selects the desired 200 MHz

harmonic. The YIG filter is tuned by

varying the current through a pair of

coils, which change magnetic fields in
the assembly.

to Limiter/Attenuator A206.
diode limiter protects Mixer A205 from
power levels in excess of one watt peak

(+30 dBm).
diode attenuator section controls the
RF signal level to the mixer and
switches off the input signal during
portions of converter operation.

wave circuit assembly consisting of a
hybrid coupler, termination, mixer

diode, and dc return. The mixer pro­duces two output signals on a common
line:
ence frequency between the incoming RF
signal from A206 and the reference fre­quency harmonic from A207, and a video
signal resulting from rectification

(detection) of either the RF or refer­ence inputs. The mixer output is fed to
I.F. Processor A204.

A205 are separated in A204. The IF sig­nal is amplified by the IF amplifier and

sent on as the converter IF signal to

A106, through Delay Line A112, for

The 200

A power amplifier

c.

The local oscillator, or reference

d. Band B input signals are applied

A passive

A multistage matched PIN

e.

Mixer A205 is an integrated micro-

an IF signal equal to the differ-

f. The IF and video signals from Mixer

1-8

Figure 1-4.

1-9

TM 11-6625-3031-14

TM 11-6625-3031-14

counting.

The video signal is amplified

in the video amplifier to produce three

video outputs: (1) a threshold signal

is directed to the rear-panel SIGNAL
THRESHOLD connector through Prescaler
A109;

(2) a threshold signal, identi­fied as attenuator control, is sent to
an attenuator control circuit on Con-

verter Sequencer A203; and

(3) an

analog output is applied to the power

level control portion of A203.

g.

On A203, inputs from the lock
section of I.F. Processor A204 are
sequenced and timed to produce a lock
level signal for Control A104 and a
Band B threshold signal for Gate Gen-

erator A105.

The attenuator control

threshold signal from the video section

of A204 is combined with an input from

the converter sequencer in the attenu-

ator control to give two outputs:

(1) an attenuator control signal, acti­vated at a level approximately 7 dB
above signal threshold, sent to the PIN

attenuator of A206, to reduce signal
level into Mixer A205; and (2) a reduce
signal level sent to the front-panel

REDUCE SIGNAL indicator when the
attenuator control is sending a signal
to the PIN attenuator.

The power level
control circuit receives an analog input
from the video section of A204 and a
digital signal from the converter
sequencer of A203, and provides a signal

to the tuning circuits of A202 to set

the comb line amplitude.

The converter
sequencer function is to control the
sensing, leveling, and control of Con­verter A2.

YIG Control A202 contains circuits

h.
to step the YIG filter to the proper
comb line, and is controlled by input
lines from Converter Sequencer A204.
On-board circuits include a YIG driver
to supply the required current, a
digital-to-analog converter (DAC) to set
the approximate center frequency, and a
centering circuit to precisely center
the YIG filter passband on a comb line.
The centering process is done by modu­lating the YIG center frequency by an
auxiliary modulation coil in YIG Comb
Generator A207.

The modulation control

circuit is on A202.

1-10

TM 11-6625-3031-14

CHAPTER 2

OPERATING INSTRUCTIONS

Section I. DESCRIPTION AND USE OF OPERATORS CONTROLS

AND INDICATORS

2-1.
and Indicators.

nectors and indicators are shown in fig-

ure 2-1 and are keyed to table 2-1,

which describes their functions.

Front-Panel Controls, Connectors

Operator’s front-panel controls, con-

2-2.

Connectors.

connectors are shown in figure 2-2 and
are keyed to table 2-2, which describes
their functions.

Rear-panel Controls and

Operator’s rear-panel controls and

Key

1

2

Figure 2-1.

Table 2-1.

Control, connector

or indicator

Display

REMOTE indicator

Front-panel Controls,

Counter Front Panel

Connectors and Indicators

Functional operation

Seven-digit LED display provides
direct numerical readout of input
frequency in GHz and MHz.

When lighted, indicates that all

front-panel controls are disabled
except SAMPLE RATE. This indicator
is controlled by digital programmed
data on the General Purpose Inter­face Bus (GPIB) and by rear-panel

ADDRESS SWITCH.

2-1

TM 11-6625-3031-14

Table 2-1.

Key

3

4

5

6

7

Front-panel Controls,

Control, connector

or indicator

GATE indicator

LEVEL indicator

LOCK indicator

MANUAL SELECT/AUTO SWEEP

switch

PRESET FREQUENCY/START

FREQUENCY thumbwheel
switch

Connectors and Indicators - Continued

Functional operation

Lights when counter is in measure­ment portion of cycle.

Lights when input signal level is
high enough to be counted. Light

will blink if signal pulse repeti-

tion frequency is too low.

Lights when input signal has been
acquired.

Selects either manual or automatic

operation of counter for BAND B.

When MANUAL SELECT/AUTO SWEEP switch

(6) is set to MANUAL SELECT, thumb-

wheel switch sets PRESET FREQUENCY;

input signal frequency must be 105
to 325 MHz higher.

SELECT/AUTO SWEEP switch is set to

AUTO SWEEP, thumbwheel switch sets

sweep START FREQUENCY; input signal
frequency must be at least 105 MHz

higher than sweep start.

When MANUAL

8

9

10

11

12

13

14

BAND B 925 MHz - 18 GHz
connector

REDUCE SIGNAL indicator

BAND A 300 - 950 MHz
connector

BAND B pushbutton switch

BAND A pushbutton switch

RESET pushbutton switch

1 ms GATE pushbutton

switch

Type N precision input connector

for Band B operation.

Lights when Band B input power
approaches maximum safe operating
level.

Type BNC input connector for Band A
operation.

Selects Band B operation for frequen­cies between 925 MHz and 18 GHz.

Selects Band A operation for frequen-

cies between 300 and 950 MHz.

When pushed and released, overrides

SAMPLE RATE control, resets display
to zeros,
reading.

When pushed in, provides 10 kHz

resolution with 1 millisecond gate
time on Band B or 4 millisecond gate
time on Band A for reduced pulse
averaging error.

and initiates a new

2-2

TM 11-6625-3031-14

Table 2-1.

Key

15

16

17

18

Front-panel Controls, Connectors and Indicators - Continued

Control,

or ind

connec

icator

tor

Right RESOLUTION pushbutton
switch

Left RESOLUTION pushbutton
switch

TEST DISPLAY pushbutton

switch

TEST 200 MHz pushbutton
switch

Functional operation

Provides blanking of least signifi-

cant digit for resolution of 100 kHz

with 100 microsecond gate time on

Band B or 400 microsecond gate time
on Band A.

Provides blanking of two least sig­nificant digits for resolution of

1 MHz with 100 microsecond gate time
on Band B or 400 microsecond gate
time on Band A.

When pushed and held in, provides

test of all segments of display
LEDS.

Display should read

88 888.88.

When pushed and held in, provides

check of counting circuits.

Display

should indicate 200.00 MHz.

19

20

SAMPLE RATE control

POWER pushbutton switch

Continuously variable control which
varies display time from 0.1 to 10
seconds per reading.

Rotating con-

trol to its switched HOLD position

will cause display to hold last

reading without an update until
RESET switch (13) is pushed in.

When pushed in and released, power

counter is turned on or off.
power is on,

a green indicator is

When

visible in switch.

2-3

TM 11-6625-3031-14

Key

1

2

3

Figure 2-2.

Table 2-2.

Rear-panel Controls and Connectors

Control or connector

10 MHz OUTPUT connector

SIGNAL THRESHOLD OUTPUT
connector

GPIB IEEE STD 488/1975
ADDRESS SWITCH

Counter Rear Panel

Functional operation

Provides output of internal 10 MHz
clock; 1 Vp-p minimum into 50 ohms.

Provides pulse output representing
signal threshold level of input
pulse.

Output pulse typically
delayed 20 nanoseconds from input
pulse.

Used for frequency profile
measurements.

Address switches of counter when
General Purpose Interface Bus (GPIB)
is used.

Setting of various combi-

nations of seven switches permits

the counter to be operated in Talk,

Listen,

or Monitor modes when exter­nal GPIB controller is connected

to counter.

2-4

4

GPIB IEEE STD 488/1975

connector

5

Fuse

Provides connection to external
GPIB controller.

Slow-blow line fuse; 1.5 A at

115 Vac or 0.75 A at 230 Vac.

6

Line voltage selector

card

Selects either 115 or 230 Vac line
voltage.

Selected voltage printed

on card is visible when card is

installed.

TM 11-6625-3031-14

Key

7

8

9

10

Table 2-2.

Control or connector

AC power connector

MIN. PRF switch

STORAGE switch

GATE OUTPUT connector

Rear-panel Controls and Connectors - Continued

Functional operation

Three-prong male connector for ac
power cable.
grounding meets NEC and UL
requirements.

Selects minimum prf.
to 50 Hz position.
counter will measure very low prf
signals but reading will not auto-

matically reset when signal is

removed.

Controls display update.
ON; in OFF position front-panel
display updates continuously during
measurement cycle.

Provides gate pulse representing
actual time at which measurement is
being made. Used in frequency
profile measurements.

Third conductor

Normally set

In 0 position,

Normally

11

12

INPUT INHIBIT connector

ACCESSORY POWER OUT
connector

Connector for external pulse input
for use in frequency profile
measurements.

Provides +5, -5.2, +12, and -12 Vdc
for accessories used with counter,
such as EIP Model 400 Delay
Generator.

Section II. PREVENTIVE MAINTENANCE CHECKS AND SERVICES

2-3.

mind

your

mind

your

form

Troubleshoot with proper equipment.
Report any deficiencies using the proper

forms.

General Instructions.

Before you operate.

a.

the CAUTIONS and WARNINGS. Perform

before (B) PMCS.

b.

While you operate.
the CAUTIONS and WARNINGS.
during (D) PMCS.
After you operate.

c.

your after (A) PMCS.

d.

If your equipment fails to operate.

See TM 38-750.

Always keep in

.

Always keep in

Perform

Be sure to per-

2-4.

be performed at specific intervals.

These checks and services are to main­tain Army electronic equipment in a
combat serviceable condition; that is,
in good general (physical) condition
and in good operating condition. To
assist operators in maintaining combat
serviceability, the chart indicates what
to check.
"Equipment is not ready/available if:"
column,

PMCS Procedures.

Table 2-3 outlines the functions to

If any entry appears in the

appropriate corrective

2-5

TM 11-6625-3031-14

maintenance
restore the

condition.

2-5.

table 2-3, remove dust and loose dirt

with a clean soft cloth.

Cleaning Instructions.

a. At the interval specified in

—

action must be taken to
counter to an operational

Table 2-3.

Operator Preventive Maintenance Checks and Services

Within designated interval, these checks are

to be performed in the order listed.

B-

Before

D

- During

A

- After

NOTE

CAUTION

Do not use any solvent except
water or a mild detergent to
clean the plastic front panel of
the counter.
damage the panel.

b.

Clean external surfaces with a

clean soft cloth moistened with clean

water.

more effective cleaning.

A mild detergent may be used for

W-

Weekly

M-

Monthly

Other solvents may

Item

No.

1

2

3

4

5

6

B

x

x

Interval

DxA

WxM

Item to be
inspected

Completeness

Power cable

.

Controls and
hardware

Exterior

x

surfaces

Nameplate

x

Operational

capability

Procedures -

check for and have

repaired or adjusted

as necessary

Power cable connected

to counter.

Cuts or cracks in
outside jacket;
damage to connector
pins.

Missing or loose

knobs or hardware

Clean exterior
surfaces.

Legibility.

Perform self-test,
para 2-7 b (2).

Equipment
is not ready/
available if:

Power cable is
missing.

Power cable is
defective.

Self-test

indications

are incorrect.

2-6

TM 11-6625-3031-14

Section III. OPERATION

2-6.

carton for signs of damage before open­ing.
request that the shipper’s agent be pres-

ent when the counter is unpacked.
Visible and concealed damage claims
against the carrier or shipper can only
be filed if the agent is present or
waives his rights.

instrument supports and packing

materials.

counter.

Without applying power, check the mechan-

ical operation of all controls and

switches.

are selection of either 115 Vac or 230
Vac line voltage and connecting the
power cable to the instrument.

ready for operation from a 115 Vac power

line, with a 1.5 ampere slow-blow fuse

installed.

voltage selector card (6, fig. 2-2),

visible through the window in the fuse

cover,
volts.

Assembly and Preparation for Use.

a. Unpacking.

—

(1) Visually inspect the shipping

If there is any apparent damage,

(2) Open the carton, removing

Carefully lift out the

Inspect the counter for damage.

b. Assembly

—

(1) The only assembly requirements

Be sure only the specified power

cable is used.

is provided with a 3-wire cable

which grounds the instrument

cabinet.
be inserted in a socket outlet

provided with a protective ground

contact.

should not be negated by the use

of an extension cord without a

protective ground conductor.

(2) The counter is normally shipped

to be certain that it reads 115

The FUSE FULL lever attached to
the body of the power module
housing does not come off.

This cable should only

This protective action

Check the marking on the line

The instrument

CAUTION

Firm

UNDER USUAL CONDITIONS

lifting up on the FUSE PULL lever and
check that it is a 1.5 ampere fuse.

with one of the correct value and con-

nect the power cable to the ac power
connector.

operation,

slide the fuse cover to the left and
remove the fuse by lifting up on the
FUSE PULL lever; see CAUTION above.

selector card.

appropriate marking (115 or 230 volts)

will be visible when the card is

inserted into the card slot.
but firmly insert the card into the
slot, being careful not to cant or tilt
the card while inserting.
seating by sliding the fuse cover from
left to right.
seating, slide the fuse cover back to
the left to gain access to the fuse

clip.

the correct value (1.5 amperes for 115

Vat, 0.75 ampere for 230 Vac) in the
fuse clip;
puller does not obstruct the fuse cover
by sliding the fuse cover to the right.

the ac power connector.

special procedures are necessary if the
counter is used as a stand-alone test
instrument.
ing the signal to the selected connec­tor and selecting the desired switches

and controls is all that is required.

but careful rotation of the fuse
puller will lift up one end of the
fuse so that finger force can re-

move the fuse. Failure to heed

this caution by exerting too much
force may damage the plastic pivot

of the built-in fuse puller.

(3) Remove the installed fuse by

(4) Reinstall or replace the fuse

(5) To change the line voltage

proceed as follows:

(a)

On the rear of the counter,

(b)

Extract the line voltage

(c)

Rotate the card so that the

Carefully

Check the

After checking the card

(d) Insert a slow-blow fuse of

check that built–in fuse

(e)

Connect the power cable to

c. Preparation for Use.

—

(1) Stand-alone Operation. No

Applying power and connect-

2-7

TM 11-6625-3031-14

(2) GPIB Operation. Installation

of the counter in a GPIB-controlled

system will vary with console or rack
hardware.
cedures can be suggested.

counter are 3.5 inches high by 16.75
inches wide by 19 inches deep.

mounting kits are available from the
manufacturer of the counter to mount

the instrument in a standard 19 inch

width rack-mount cabinet or console.
Ventilation of the counter is through

the rear panel so it is not necessary

or desirable to remove the top and bot-

tom covers for cooling.
covers should remain in place secured

by screws to retain RFI integrity.

required to control selector switches
and the GPIB address switches.
panel ventilating louvers and blower
should not be blocked off from free air
flow.

sources to—the counter front-panel con-

nectors should be as short as possible.
A common ground bus should tie the

counter to other instruments and the

GPIB controller.

cable is not critical but the supplied
cable should be retained and plugged
into a powerline strip.

interface cable should be as short as
feasible and should be shielded against

RFI to reduce data transmission con-

tamination.
program controller may be connected,
provided that the controller meets IEEE
Standard 488/1975.

2-7.

Instrument.

a. Operating Modes.

three principal modes of operation:
automatic, manual, and externally en­abled.
MHz) is automatic;

(925 MHz ­matic or manual.
operation covers specific measurement

techniques.

Therefore only general pro-

(a)

The dimensions of the

Rack

Top and bottom

(b)

Access to the rear panel is

The rear

(c) Leads from frequency

The length of power

(d)

The length of the GPIB

Any keyboarding or fixed

Operation as Stand-alone

The counter has

Operation on Band A (300 - 950

operation on Band B

18 GHz) may be either auto-

Externally enabled

Signals may be connected to

both the BAND A and BAND B inputs at the

only the input frequency selected by the
appropriate BAND pushbutton switch on

panel switches as follows.

ADDRESS SWITCH 7 to 0 (top of switch
depressed).

light and the internal cooling fan
should operate.

of the two RESOLUTION switches and
release it, so that neither switch
remains in a depressed position.
digits in the display should indicate
zero.

switch.
88 888.88 while the switch is held in.
Release the switch.

switch.

200.00, with the two leading zeros
blanked (unlighted), while the switch is
held in.

switch and again hold the TEST 200 MHz
switch in.

200.0, with the two leading zeros
blanked.

digit immediately above the switch
which has been depressed, and any digit

by repeating step (b).

same time,

the front panel.

b. Preliminary Procedures.

—

(1) Rear-panel Switches. Set rear-

(2) Self-test.

turn on the counter. The display should

switch in turn and note that the display

to the right, is blanked.

c. Band A (300 -

Peak power applied to the BAND A
input connector should be between

-10 and +10 dBm for normal oper­ation.

but the counter will display

(a)

GPIB IEEE STD 488/1975

(b)

MIN. PRF switch to 50 Hz.

(c)

STORAGE switch to ON.

(a) Press the POWER switch to

(b)

Partially depress either

All

(c) Press the TEST DISPLAY

The display should indicate

(d)

Press the TEST 200 MHz

The display should indicate

Release the switch.

(e)

Press the right RESOLUTION

The display should indicate

Release the switch.

(f)

Press each RESOLUTION

(g)

Unblank all display digits

950 MHz) Operation.

CAUTION

Peak input must not

2-8

exceed +27 dBm or damage to the
counter may result, even if the
counter is turned off.

(1) Perform the preliminary proce-

dures of step b.,

(2) Connect the signal source to

the BAND A input connector.

(3) Depress the BAND A switch.
(4) Depress the desired RESOLUTION

switch.

(5) If the input signal level is
high enough for counting, both the LEVEL
and LOCK indicators will light, and the
measured frequency will be displayed.

The REDUCE SIGNAL indicator is
inoperative on Band A.

(6) Turn the SAMPLE RATE control to

provide the desired display update rate.

The GATE indicator will flash in accord-

ance with the sample rate.
control is set to its switched HOLD
position,
last reading.
desired, press and release the RESET
switch.

d. Band B (925 MHz - 18 GHz)

Operation.

Peak power applied to the BAND B

input connector should be within
the following ranges for normal

operation:
925 MHz - 10 GHz: -10 to +10 dBm

10 -

The peak input power must not ex-

ceed +30 dBm or damage to the
counter may result, even if the
counter is turned off.

procedures of step b above.

to the BAND B input connector.

the display will retain the

18 GHz:

(1) Initial Procedures.

(a)

(b)

(c)

above.

NOTE

If the

If a new reading is

CAUTION

-5 to +10 dBm.

Perform the preliminary

Connect the signal source

Depress the BAND B switch.

RESOLUTION switch.

is high enough for counting, both the

LEVEL and LOCK indicators will light.

If the REDUCE SIGNAL indicator lights,
the input signal power is approaching
the maximum safe operating level and

should be reduced.

matic mode,

input signal by sweeping from a start
frequency which is 105 MHz above a pre­set frequency.

SWEEP switch to AUTO SWEEP. For full
search,
switches to 00.0 GHz.

speed, the sweep start frequency may be
set by means of the START SWEEP thumb-

wheel switches.
which can then be acquired and displayed
will be 105 MHz above the switch set-

tings; erroneous readings may be dis­played if the frequency of the applied

signal is less than 105 MHz above the

switch settings.

control as described in paragraph

2-7 c (6).

mode,

reducing the acquisition time. However,

the signal frequency to be measured

must be between 105 and 325 MHz above a

preset frequency.

SWEEP switch to MANUAL SELECT.

thumbwheel switches so that they indi-

cate a frequency 105 to 325 MHz lower

than the signal frequency. For example,

if the frequency to be measured is ex-

pected to be 12.35 GHz, the thumbwheel

switches should be set to indicate 12.2
GHz, which places the input frequency

105 to 325 MHz above the preset fre­quency.
played if the frequency of the applied
signal is outside the preset range.

control as described in paragraph
2-7 c (6).

TM 11-6625-3031-14

Depress the desired

(d)

(e)

If the input signal level

(2) Automatic Mode. In the auto-

the counter searches for the

(a)

Set the MANUAL SELECT/AUTO

set the START SWEEP thumbwheel

(b)

To improve acquisition

The lowest frequency

(c)

Adjust the SAMPLE RATE

(3) Manual Mode. In the manual

the search sweep is inhibited,

(a)

Set the MANUAL SELECT/AUTO

(b)

Set the PRESET FREQUENCY

Erroneous readings may be dis-

(c)

Adjust the SAMPLE RATE

2-9

TM 11-6625-3031-14

2-8.

panel INPUT INHIBIT connector makes
possible a class of measurements known
as dynamic frequency
measurements made at a specified point

in time on a signal whose frequency is
some repetitive function of time.
a high emitter-coupled-logic (ECL) level
is applied,

from making a measurement. Thus a sig­nal at the INPUT INHIBIT connector can
be used as an enable signal to make a
measurement at a desired time.
width of the enable signal determines

the duration of the measurement, typi-

cally 30 nanoseconds less than the

applied pulse.

INPUT INHIBIT circuit is designed to be

compatible with either a 50 ohm imped-

ance pulse generator or ECL devices.

An internal termination of 50 ohms

returned to -2 volts makes this dual

compatibility possible.

level signal (-0.8 to -1.1 V) will

inhibit measurement, while an ECL low

level signal (-1.5 to -2.0 V) will

enable measurement.

designed to drive 50 ohm lines without

reflections when the lines are termi-

nated with 50 ohms returned to -2 V.

The direct compatibility with a 50 ohm

pulse generator results from the fact

that zero volts from a 50 ohm source

will produce

(inhibiting the counter), while a -1 V

signal into 50 ohms will produce -1.5 V

at the INPUT INHIBIT thus enabling the

counter.
2-9.

Externally Enabled Operation.

a.

Function.

b.

INPUT INHIBIT Requirements.

Pulse Profile Measurements

The use of the rear-

measurements -

the counter is inhibited

An ECL high

ECL devices are

-1 V at the INPUT INHIBIT

The

When

The

ments of these characteristics are

easily made with the counter and a

delaying pulse generator (see fig. 2-3).

The SIGNAL THRESHOLD OUTPUT of the coun-

ter is used to trigger the pulse genera-

tor. The generator’s output pulse is used

as an enable input to the counter. As the

pulse delay is varied, the measurement

window can be “walked” through the pulse.

A plot of frequency versus delay gives

the frequency-versus-time profile of the
pulse directly as shown in fig. 2-4. The
width of the measurement window is deter-

mined by the width of the pulse genera-

tor output.

nanoseconds or less can be used, although
wider windows yield higher accuracy.

b. Measurement Technique. Measure-

Figure 2-3.

Measurement Test Setup

Measurement windows of 50

Pulse Profile

a. Purpose.

ments can determine the average fre-

quency of a pulse.
however,
necessary.

tron may exhibit substantial frequency

shift near the leading and trailing

edges of the pulse, or a pulsed Gunn
diode oscillator may exhibit frequency

shift during a pulse due to peak power

thermal effects.

2-10

additional information may be

Automatic pulse measure-

In some cases,

For example,

a pulse magne-

Figure 2-4.

Pulse Profile Measurement

TM 11-6625-3031-14

2-10.

Varying Signals.

not pulses at all but simply continuous

signals whose frequency varies repeti­tively with time. One example is the

measurement of the response of a device

such as a voltage-controlled oscillator

(VCO).

tuning voltage will produce a response

curve of frequency versus time, allowing

measurement of various settling times

such as post-tuning drift.
sible application would be the measure-

ment of linearity and amplitude for

frequency-modulated radar altimeter
signals.

shows a test setup designed to make

measurements on time varying signals.

It is similar to the pulse profile test
setup, except that in this case, since

there is always a signal present, a
trigger must be obtained from the modu­lating source.
pulse generator which controls the

measurement.

2-11.
Measurements.

ment is that of a repetitive sequence of
pulses differing in frequency. In this

Dynamic Characteristics of Time

a.

Purpose.

A square wave applied to the

b. Measurement Technique.

Multiple Pulse Signal

a.

Purpose.

Figure 2-5.

Measurement Test Setup

Many complex signals are

Another pos-

Fig. 2-5

This will trigger the

Another type of measure-

Time Varying Signal

measurement window is the period during
which the gate is actually open to en­able the counting of a signal.
gate width will typically be 30 nano­seconds narrower than the pulse applied

width of the gate is always an integral

number of clock periods (5 nanoseconds).

For applications where the measurement
window needs to be known to an accuracy
better than 20 nanoseconds, it is rec-

ommended that the GATE OUTPUT on the

rear panel be observed directly on a
high speed oscilloscope. The desired
gate width may then be set by varying

the INPUT INHIBIT pulse width.
accurate pulse representation, the
oscilloscope input should be terminated

in a 50 ohm load.

necessary to measure the signal fre­quency at a precise point in time, the
internal delays of the measuring instru­ment can be significant. The total
delay between the time a signal is
applied to the counter input connector,
and the time it is available to be

case, it is desirable to measure the
frequency of each pulse in the sequence
separately.

b. Measurement Technique. The same
test setup as shown in fig. 2-5 is
required, with the trigger pulse syn-

chronous with the sequence.

measurement,

simply to discriminate between pulses.

The enabling pulse can be slightly
wider than the pulse to be measured.
The counter will automatically restrict

the measurement window entirely within

the pulse.

the enabling pulse,

the sequence can be separately measured.

2-12.

internal timing within the counter is of
no concern to the user.
applications where a few nanoseconds are
significant,
operation are important.
two areas:
and internal timing delays.

b. Measurement Window Width. The

to the INPUT INHIBIT connector.

c.

Timing Considerations.

a.

General.

Internal Timing Delays.

the INPUT INHIBIT is used

By shifting the delay time of

each input pulse of

Under most circumstances,

some details of internal

measurement window width

In this

However, in

These involve

This

The

For

When it is

2-11

TM 11-6625-3031-14

counted,

The SIGNAL THRESHOLD OUTPUT on the rear

panel typically occurs 20 nanoseconds
after the signal is applied.

OUTPUT at the rear panel occurs at the
measurement time with virtually no
delay.

time positioning of a signal is required,

it is necessary to consider that the
GATE OUTPUT signal,

measurement period, is actually making

a measurement of the signal which
appeared at the input connector 60 nano-

seconds earlier. If the SIGNAL THRESH­OLD OUTPUT is used as an indication of

input signal, then it occurs 40 nano-

seconds prior to measurement.

shows the relative timing of these sig­nals for a pulsed input signal.

however, is not a function of input sig­nal characteristics.

2-13.

a. General Considerations.

—

measurement accuracy is generally speci-

fied as time base accuracy ±1 count.
This means that the frequency measure­ment is in error by the same percentage
as the time base reference oscillator.

The maximum error in the time base is

the sum of various possible errors,
such as aging rate, temperature, etc.

count, is derived from the relative
timing of gate and signal.

stated, if an event occurs every 400
milliseconds,

Figure 2-6.

is nominally 60 nanoseconds.

The GATE

In other words, when absolute

which represents the

Fig. 2-6

Timing,

Accuracy.

(1) In a cw frequency counter,

(2) The second type of error, ±1

Simply

a counter could measure

Internal Timing Delays

either 2 or 3 events in a one second
interval,
signal and the gate are asynchronous.

error in a cw counter is gate error.
A gate is supposed to represent a pre­cise number of reference oscillator
cycles.
in the rise and fall times of various
circuits,
be a fixed amount wider or narrower
than desired. If this error is less
than one period of the maximum input
frequency, no counter error will occur.

Thus a 300 MHz counter needs a gate

accurate to about 3 nanoseconds.

error can contribute to the overall
error In pulse frequency measurements.
In fact for narrow pulses, the second
and third sources of error, which are
usually ignored in a cw counter, become
the dominate sources of error in a
pulse counter.

error in the time base reference oscil­lator results in a proportional fre­quency measurement error.
sources of time base error are aging
rate and temperature. The temperature
compensated crystal oscillator (TCXO)
reduces temperature instability to less
than 2 x 10-6.

frequency standard, this error can be
made less than one count, and thus
becomes insignificant.

obtain high resolution, the frequency

of a number of measurements is averaged.

Each individual measurement has a ±1

count uncertainty as previously noted.

If N measurements are made, then an

uncertainty of ±N counts is possible,
but very unlikely.

averaged measurement will follow the

rules of statistics, in that succes-

sive measurements will vary randomly

to a certain degree.

of the readings (63 percent) will fall

between ± counts; this is called

the rms averaging error.

number of gates required to accumulate

100 microseconds or 1 millisecond of

gate time.

since the processed input

(3) A third possible source of

Due primarily to differences

the actual gate will usually

(4) Each of these three sources of

b.

Time Base Errors. A frequency

Two main

By calibration against a

c.

Averaging Error. In order to

The resultant

In fact, most

N is the

The gate is typically

2-12

TM 11-6625-3031-14

30 nanoseconds

pulse, so that

narrower than the input

determined and corrected. As an
example, the measured time base output
is 10.0001 MHz.

1 x 10

readings will be 1 x 10

quency.

where PW =

F

= 200 kHz with 100 µsec gate,

pulse width in microseconds

Band A; or 60 kHz with

be 10 kHz low.
can be corrected for this error, the
counter should be recalibrated as soon

as possible.
1 msec gate, Band A; or
100 kHz with 100 µsec gate,

Band B; or 30 kHz with

1 msec gate, Band B.

quency and pulse width can be virtually

eliminated.

simulating a pulse input and determining

d.

Gate Error.

(1) When narrow pulses are counted,
the gate is opened many times in order
to obtain a high resolution measurement.

the gate error.
can then be added to, or subtracted
from,

obtain the correct frequency.
Each time the gate opens and closes,
there will be a small but finite error.
The total error is proportional to the
number of times the gate is cycled dur­ing a measurement, and is thus inversely
proportional to the gate width.

This
error is also related to both tempera­ture and input frequency.
case error,

including all variables, is

The worst

specified for the counter as:

error using a cw source at approxi-

mately the same frequency (within

25 MHz) as the indicated measurement.

A pulsed input is then simulated by

applying an enable signal, of the same

width as the pulse to be measured, to

the INPUT INHIBIT connector.

error is the difference in reading
between the pulsed and non-pulsed
measurement of the same cw signal.
This procedure provides the true gate

error,
any possible pulling of the signal

source.

-6

high in frequency, and all

The time base is thus

-6

low in fre-

Thus, a reading at 10 GHz will

Although the reading

b. Gate Error.

—

(1) Gate error at any given fre-

This is accomplished by

This calibration factor

the indicated measurement to

(2) First, determine the gate

Gate

and avoids error associated with

where PW =

pulse width in microseconds.

(2) Unlike averaging error, which
is random, gate error is systematic,
and is not reduced by frequency
averaging.

2-14.

Techniques for Improving

Accuracy.

a. Time Base Calibration. A frequency
error in the time base oscillator re­sults in the same percentage error in
the frequency reading for either cw or
pulsed signals.

By directly measuring

the 10 MHz time base frequency at the

10 MHz OUTPUT connector with a standard

of known accuracy, this error can be

2-15.

Operation Using General Purpose

Interface Bus.

a. General.

—

(1) The counter may be operated via
the General Purpose Interface Bus (GPIB)
and may be controlled by, listened to
and talked to by any device or devices
compatible with IEEE STD-488.

Table 2-4
lists the Capability Identification
Codes assigned to the counter.

This
code is also printed on the counter rear
panel adjacent to the GPIB 24-pin con­nector so that programming instructions
or keyboarding of a controller can be
interfaced with the counter configura­tion and capabilities.

(2) The IEEE STD-488 GPIB system

(fig. 2-7) consists of 16 signal lines

2-13

2-14

Table 2-4.

TM 11-6625-3031-14

TM 11-6625-3031-14

used to carry data, control, and
management information.

The 16 lines

are organized into three sets, as

follows:

(a) Data Bus ­(b)

Control -

3 signal lines

(c)

Management-

Data Byte Transfer

General Interface

5 signal lines.

8 signal lines

(3) The counter is a type B device

able to talk and listen (T1 and L4

codes). Mnemonics assigned to the vari-

ous signal lines are as follows:

(a)

Data Bus lines are:

DIO 1 through DIO 8 (Data Input/Output

line 1 through 8)

- used to transmit

message bytes in bit-parallel, byte-

serial format,

asynchronously and

usually in a hi-directional manner.

(b)

Data Byte Transfer Control

lines are:

DAV (Data Valid) - used to indicate the

condition (availability and validity) of
information on DIO signal lines.

Figure 2-7.

and Structure

GPIB Capabilities

NFRD (Not Ready For Data) - used to in­dicate the condition of readiness of
device(s) to accept data.

NDAC (Not Data Accepted) - used to indi-

cate the condition of acceptance of data

by device(s).

(c) General Interface Manage-

ment lines are:
ATN (Attention)

- used by a controller
to specify how data on the DIO signal
lines are to be interpreted and which

devices must respond to the data.

IFC (Interface Clear) - used by a con­troller to place the interface system,

portions of which are contained in all

interconnected devices, in a known

quiescent state.
SRQ (Service Request) - used by a device

to indicate the need for attention and
to request an interruption of the cur-

rent sequence of events.

REN (Remote Enable) - used by a con-

troller (in conjunction with other mes-

sages) to select between two alternate

sources of device programming data.

2-15

TM 11-6625-3031-14

EOI (End Or Identify) - used by a talker

to indicate the end of a multiple byte
transfer sequence or, in conjunction

with ATN (by a controller), to execute a

polling sequence.

NOTE

The EOI function is not included
in this counter.

(4) The 16 GPIB lines are connected

to the rear-panel GPIB IEEE STD 488/

1975 connector as shown in table 2-5.
To the left of and below the connector
are seven ADDRESS SWITCHes for setting

the GPIB modes or addresses of the

counter.

b. On Line and Off Line Operation.

(1) The Talk Only On Line and Off
Line operation are summarized in table
2-6.
determines the mode of operation of the
counter. When the switch is set to the

1 position before power is applied to

the counter,

The setting of ADDRESS SWITCH 7

the counter can be a talker

Table 2-5. GPIB IEEE STD 488/1975

Connector Pin Assignments

Pin

10
11
12

Signal

1

DIO 1

2

DIO 2

DIO 3

3

DIO 4

4

EOI

5

(not used)

DAV

6

NRFD

7

NDAC

8

IFC

9

SRQ

ATN

(Shield)

line

Pin

13
14
15
16

17

18

19
20
21
22
23
24

Signal

line

DIO 5
DIO 6
DIO 7
DIO 8
REN
Gnd (6)*
Gnd (7)*
Gnd (8)*
Gnd (9)*
Gnd (10)*
Gnd (11)*
Gnd (Logic)*

only with continuous output from the
GPIB connector.
rate control (either by the front-panel
SAMPLE RATE control or Fast Active) and
output format (either Exponent­Scientific or Exponent-Four) is set by

ADDRESS SWITCHes 1 and 2.

other ADDRESS SWITCHes, 3 through 6, do

not effect the output when the counter

is being used in the Talk Only mode.

selected, ADDRESS SWITCH 7 is placed in
the 1 position before power is applied
to the counter. After power is applied,
the front-panel controls will be opera­tive unless ADDRESS SWITCH 1 is in the
1 position,

RATE control will be inactive.

selected, ADDRESS SWITCH 7 is placed in
the 0 position before power is applied
to the counter.

the counter is accomplished by placing
ADDRESS SWITCHes 1 through 5 in the
appropriate configuration shown in

table 2-6.

counter will respond to the ASCII Listen
or Talk Address character that has been

set by the ADDRESS SWITCHes 1 through 5,
as indicated in table 2-7. Configura-

tion of the ADDRESS SWITCHes is shown in

fig. 2-8.

Selection of sample

The four

(2) When Off Line operation is

in which case the SAMPLE

(3) When On Line operation is

Address assignment to

After being turned on, the

NOTE

ASCII ? and is reserved for

GPIB Unlisten and Untalk and
therefore cannot be assigned as
an address to a counter or any
other device.
settings of 1 1 1 1 0 cannot be
used as an address for the
counter.

ADDRESS SWITCH

*Gnd ( ) refers to the signal ground

return of the referenced contact pin;
EOI and REN (5, 17) ground return on
pin 24.

2-16

Figure 2-8. GPIB IEEE STD 488/1975

ADDRESS SWITCH Positions

TM 11-6625-3031-14

Mode

On Line
Operation

Off Line
Operation

Table 2-6.

ADDRESS SWITCH

1

2

A1

A2 A3 A4

0* 0*

1*

0*

0*

1*

1*

1*

On Line and Off Line ADDRESS SWITCH Settings

Function

5

4

3

x x x

x x x

x x x

x x x x

A5

6

7

Address assignment to counter.
ADDRESS SWITCH 7 must be in 0

0

x

position.

Continuous output determined by

1

x

x

x

SAMPLE RATE control. Exponent in
scientific format.

Continuous output, fast active.
SAMPLE RATE control inactive.

1

Exponent in scientific format.

Continuous output determined by
SAMPLE RATE control.

1

four output format.

Continuous output, fast active.
SAMPLE RATE control inactive.

1

Exponent-four output format.

Exponent-

x* x*

Don’t care

x =
*

= May be continuously set or reset as long as ADDRESS SWITCH 7 is set to 1 during

power application. After application of power,
to 0.

c. Remote/Local Operation.

(1) In addition to On Line and Off
Line modes of operation, the GPIB pro­vides for Remote and Local Operation.

In Remote Operation, the counter is On
Line and is under control of programming
signals from a controller. In Local
Operation, the counter front-panel con­trols are active and controller signals

do not affect counter operation; how-

ever,
the GPIB (Talker Only Mode) depending
on the counter rear-panel ADDRESS
SWITCH settings.
switch between Remote and Local by
sending the appropriate ASCII codes for
Remote Enable (REN) or Go To Local con­trol (GTL) to the counter.

in Remote and the controller has

output signals are available to

The controller can

(2) When the counter is On Line and

x x x

0

x

No output

ADDRESS SWITCH 7 may be set

selected the counter with ATN (Atten-

tion) to the counter address followed
by Listen,
programming instructions from the con-

troller.

select all control functions of the

counter front panel except power on/off,

sample rate,

instructions from the controller to the

counter are identified as Device Depend-

ent Data.

d. Device Independent Data, On Line

Operation.

consists of the following, which are

sent by controller while in the command
mode.

(1) GO TO Local (GTL). An

addressed command given by the con-

troller.

its Listen address prior to the GTL

the counter will respond to

Programming instructions can

and self-test. Programming

Device independent data

The counter must have received

2-17

TM 11-6625-3031-14

ADDRESS SWITCH

1

0

1

0

1

0

1
0
1
0
1
0
1
0 0

1

2 3 4

Setting

0 0 0
0 0

1

1
0
0

1 1

1
0
0 0

1

1

0

Table 2-7.

0
0 0
0

1
1

1

0

0
0

1 1
1 1 1

0

0

0

0

0

1
1
1
1

ADDRESS SWITCH Settings vs ASCII Characters

ASCII

5

1
1
1
1
1
1

1

1
1

1

1
1
1

Listen address Talk address Talk/Listen

character character address

SP

!

"
#

$
%
&

'

(

)
*

+

,

ASCII *Decimal

@

A

B
C
D 04

E

F 06
G
H 08

I
J
K
L
M

00
01
02
03

05

07

09

10

11

12
13

0

1 1

0

1

0

1

0 0

1

0

1 1

0 0

1

0

1

0

1
0

*Decimal Talk/Listen addresses are provided as a cross-reference for controllers

which use them in their program instructions.

1

0
0

1

1

0

1

0

1

1
0
0

1

1

1
0
0
0
0

1
1
1

1
0
0

0
0

1

1 1

1

1

1
0 0
0
0 0
0 0 3

0 0

0 0

0

0

1
1
1
1

1

1

1
1

0

0
0
0
0
0
0
0
0
0

:

,

.

/
0

1

2

4
5
6

7
8
9

<
=

>

N
O
P

Q
R

S
T
U
V
W

X
Y

Z

[

\

]

14
15

16
17
18

19
20
21
22
23
24
25

26
27

28
29

30

2-18

TM 11-6625-3031-14

command being issued.
received,

the counter will go to the
Local mode with all front-panel
switches operative.

When GTL is

Fast Cycle, or the

one alpha and one numeric, characters,
depending on the function being

programmed.
last YIG Preset command received by the
counter while in the Remote mode, will
remain and will not be cleared by this
command.

The front-panel REMOTE indi-

of the value portion of the function

being programmed.

optional.)
cator will be off.

(2) Selected Device Clear (SDC).

An addressed command given by the con-

troller.

The counter must have received

numeric value assigned to the function

being programmed.

zeros need not be programmed.
its Listen address prior to the SDC
command being issued.
received, the counter will be cleared
to its initial state and remains

When SDC is

symbol used with the value portion of

the function being programmed M = mega-

hertz (106), G =
addressed to Talk or Listen. ADDRESS
SWITCHes 1 - 7 will be read.

(3) Device Clear (DCL). Same as

SDC command, except that counter’s

Listen address does not have to be

received prior to issuing of DCL.

(4) Serial Poll Enable (SPE). An

addressed command given by the

controller.

(5) Serial Poll Disable (SPD). An

addressed command which negates SPE.

Device Dependent Data, On Line

e.

Operation.

(1) Definition.

data is that data,

Device dependent

inputted in string
form, to which the counter uniquely
responds while in the Remote mode, and

while addressed to Listen.

(2) Implementation. While in the

command mode,

the controller places the
counter in the Remote mode by setting
the REN line active, then by sending the
listen address of the counter.

When the

command will program a YIG Preset equal

to the Value and Scale Factor. Nega-

tive YIG Presets will be taken as
positive.
al), Value and Scale Factor.

Example:

counter is in the Remote mode and ad­dressed to Listen, the controller

leaves the command mode and enters the

data transfer mode.

It is in this
mode and counter setup that device
dependent data can be sent by the pro­grammer.

The mnemonics, format, and
specifications for the device depend­ent data are described below and sum-

Example:

Between YP and M or G, only the Sign,

numeric Value, or decimal point will be

recognized by the counter.
information will be updated only during
a converter reset.

marized in table 2-8.

(3) Format.

The format for device
dependent data from a controller is as
follows:

Mnemonic

Sign

Value Scale Factor

(a) Mnemonic. Two alpha, or

(b) Sign. The sign “+” or “-”

(The “+” sign is

(c) Value.

The particular

Leading and trailing

(d) Scale Factor. Exponent

9

gigahertz (10

).

NOTE

If any of the above does not per-

tain to the particular function
being programmed, it should be
omitted.

For example, BA:

Mnemonic.

The Sign, Value, and

BA is the

Scale Factor are not necessary.

This function sets the counter to

Band A.

(4) Mnemonics.

(a) YIG Preset (YP). This

Mnemonic YP, Sign + (option-

YP 1.2 G or YP - 1.2 G.

Both
program 1.2 x 109 Hz (1.2 GHz)
into the counter.

YP M or YP G:

Clears the YIG

Preset.

YIG preset

NOTE

In the following commands, the
Mnemonic is shown following the
command title. Sign, Value, and
Scale Factor are not used.

2-19

TM 11-6625-3031-14

Table 2-8. Programming Summary

Function Value

YIG Preset

Cycle
Counter

Reset
Counter and
Converter

Converter

Auto

Converter
Manual

Hold Active

Hold Passive

1 ms Gate

Time Active

1 ms Gate

Time Passive
Band A

ASCII

Mnemonic

YP

CC

RC

CA

CM

HA No data

HP
TA Gate time:

TP

BA

Sign

+

range

Scale
Factor

M or GYIG preset

Comments

+ sign optional

One-shot action

One-shot action

transmission

1 ms

Gate time:

100 µs

Band B
Remote

Resolution:

10 kHz

Remote
Resolution:

100 kHz

Remote
Resolution:

1 MHz

Fast Active

Fast Passive

Transmit
Normal

Transmit

Service
Request

Exponent­Scientific

Exponent­Four

BB
R4

R5

R6

FA
FP

TN

TS

ES

E4

Sample rate

Sample rate

Output data

Output data

2-20

TM 11-6625-3031-14

Function

Device Clear

(DCL)

Selected
Device Clear

(SDC)

Go to Local
Control

(GTL)

Serial Poll
Enable (SPE)

Serial Poll

Disable

(SPD)

My Listen

Address

(MLA)

My Talk
Address

(MTA)

Table 2-8.

ASCII

DC4

EOT

SOH

CAN

EM

Mnemonic

Programming Summary - Continued

Sign Value

Scale

Factor

Controller
dependent

Controller
dependent

Controller
dependent

Controller
dependent

Controller
dependent

Device dependent

Device dependent

Comments

Unlisten Controller

dependent

Untalk Controller

(b) Cycle Counter (CC). This
command resets the basic counter sec­tion,
ing.
reset occurs; to obtain another reset,
CC must be resent.

(RC).
basic counter and converter sections,
and causes the counter to take a new

reading.
occurs;toobtain another
must be sent again.

HA is sent in the Remote mode, the

counter stops taking readings, data

transmission is stopped, and the last

frequency read is displayed and held by

the counter.

(subparagraph (s)

will have no effect upon the counter’s

and causes it to take a new read-

When the CC command is sent,

(c)

This command resets both the

When RC is sent, a reset

(d) Hold Active (HA). When

—

Reset Counter and Converter

reset, RC

In the Fast Active mode

below), the HA command

dependent

display operation while in the Local

mode, but will stop data transmission.

If programmed during the FA mode, and FA
is then terminated, the counter will
respond to the HA command.

(e) Hold Passive (HP). This

command terminates HA.

1 ms Gate Time Active (TA).

(f)

This command puts the counter in the

1 ms gate time mode.

1 ms Gate Time passive

(g)

(TP).

selects Band

to 950 MHz.

selects Band

to 18 GHz.

command selects the automatic sweep

mode of the counter, and operates in

This command terminates TA.

(h)

Band A (BA).
A of the counter, 300 MHz

(i)

Band B (BB).
B of the counter, 925 MHz

Converter Auto (CA). This

(j)

This command

This command

2-21

TM 11-6625-3031-14

conjunction with the YIG Preset (YP)
command and value,

(k)

Converter Manual (CM).
This command selects the Manual mode
of the counter, and operates in conjunc-

tion with YIG Preset (YP) command and

value.

(m) Transmit Normal (TN). This

command causes the counter to continu­ously transmit its reading when addres­sed to Talk.

(n)

Transmit Service Request

(TS).

This command causes the counter

to take a reading, format the data,
store the result, and activate the SRQ
line to indicate to the controller that
a reading is ready for transmission.

After the reading is transmitted, the

SRQ line is deactivated and the process

is repeated.

The status byte trans-

mitted during serial polling indicates

that data is ready for transmission

(bit 7 active).

NOTE

f. Output Data Format.

—

(1) Basic Format.

(a) The output data is trans-

mitted with the most significant byte

first,
form, and in 7-bit ASCII code.

in a bit-parallel, byte-serial

The

general format is

XX.XXX xx Ey CR LF

where CR is Carriage Return, LF is
Line Feed,

x represents digits 1 through
9, and y the exponent 0, 3, 6, or 9.
The decimal point will be located in
the proper place, though it may be
deleted depending on the data output
format and/or the reading.

(b)

There will always be

12 bytes of information transmitted per

reading.

Leading zeros are always re­placed with ASCII code Null characters.
The last four bytes transmitted are
always

Remote Resolution commands deter­mine the resolution of the

counter readings while in the

Remote mode.

where y represents exponents 0, 3, 6, or

9, and CR and LF the ASCII codes used
as delineators.

(p) Remote Resolution: 10 kHz

(R4).

(R5).

(R6).

Resolution of 10 kHz.

(q) Remote Resolution: 100 kHz

Resolution of 100 kHz.

(r) Remote Resolution: 1 MHz

Resolution of 1 MHz.

(s) Fast Active (FA). The FA

is used to—specify the exponent 0, 3,
6, or 9, depending upon the value and
format of the reading.
output commands (E4 or ES) affect only
the numeric portion and exponent value
of the transmitted data.

command causes the counter to go into
the fast cycle mode of operation. In

Format.

this mode, the front-panel SAMPLE RATE
control is inactive, and the fastest
sample rate transmissions are attained.

(t) Fast Passive (FP). This

command terminates FA.

(u)

Exponent-Scientific (ES).

This command causes the counter to out-

put data in an engineering notation
format if counter is addressed to Talk.

(v) Exponent-Four (E4). This

command causes the counter to provide

exponent value of the transmitted data
will always be 4 with no decimal point
inserted.
mitted as seen on the counter’s front­panel display, with the resolution of
the reading dependent upon the front­panel switches or the remote resolution
commands.
resolution setting are set to zero.
Some examples in the E4 format are as

data in four exponent format if counter

is addressed to Talk.

Null character.

Ey

CR LF

(c)

The ASCII code character E

Thus the data

(2) Exponent-Four Output (E4)

(a) In the E4 format, the

The reading will be trans-

The digits affected by the

follows, with N representing an ASCII

(b)

Display reading:

11 234.56 MHz

Resolution

10 kHz

100 kHz

1 MHz

(c) Display reading:

434.56 MHz

Resolution

10 kHz

100 kHz

1 MHz

Reading transmitted
N1123456 E4 CR LF

N1123450 E4 CR LF

N1123400 E4 CR LF

Reading
NNN43456 E4 CR LF

NNN43450 E4 CR LF
NNN43400 E4 CR LF

transmitted

TM 11-6625-3031-14

switches on the counter front panel),
those digits affected by the resolution
are replaced by zeros.
ES format are:

Frequency input:

1.

1 234.56 MHz

Remote

resolution

10 kHz

100 kHz

1 MHz

.56 GHz

Reading transmitted

N 1.23456 E9 CR LF
NN 1.2345 E9 CR LF
NNN 1.234 E9 CR LF

2. Frequency input:

Examples in the

(3) Exponent-Scientific Output (ES)

Format.

(a) In the ES format, the
exponent value of the transmitted data
is always 0,
the frequency reading.
is entered to correspond to the exponent

so the transmitted data will be a mixed

number of whole and fractional parts,

such as 545.727, 15.72, 5.2, etc.

transmitted as ASCII Null characters,
and the digits which are affected by the
remote resolution are disregarded.

(Null characters are inserted at the

beginning of the data so that 12 charac-

ters are always transmitted.)

quency reading includes a decimal point

that is not necessary, the decimal point
is disregarded and a Null character is
inserted at the beginning of the data.

the whole part of the number being
transmitted (no decimal point or frac­tional part), zeros are inserted for
those numbers before being transmitted.

the entire—number,
transmitted with the exponent value of
the reading,
exponent value the manner in which the
resolution covered the reading.
example:
NNNNNNNOEO CR LF.

used (by pressing the RESOLUTION

3, 6, or 9, depending on

A decimal point

(b)

All leading zeros are

(c)

If the resolution or fre-

(d)

If the resolution affects

(e)

If the resolution covers

then all Nulls are

so the user can tell by the

For

0 Hz is transmitted as

(f) When local resolution is

printed out on a printer, are shown

below.

conditions of the counter
Line mode, after power is
commands SDC or DCL have been issued by

the controller, are as follows:

are in tri-state mode.

(REMOTE indicator not lighted).

SWITCHes 1 through 7.

Talk or Listen

Remote

resolution

10 kHz

1 MHz

(g) Transmitted readings, as

Leading Null characters are not

printed.

Printer output

434.6E6 434 600 000 Hz

11.7693E9

539.99999E9
OEO 0 Hz

g. Wake-up Conditions.

(1) Signal lines of the data bus

(2) Counter is in Local mode

(3) Counter has sampled ADDRESS

(4) Counter is not addressed to

(5) No YIG Preset (YP).

Reading

NN 560.00 E6 CR LF
NNNNN 560 E6 CR LF

NOTE

539 999 990 Hz

E6

? but

transmitted

Frequency

11 769 300 000 Hz

in MHz range

The wake-up

for the On

applied or

2-23

TM 11-6625-3031-14

(6) Transmit
(7) Remote ­(8) Remote ­(9) Remote -

Passive (TP).

(10) Remote -

(R4).

(11) Remote ­(12) Remote -

(ES) format.

(13) Remote ­(14) Counter and converter have been

reset.

h. Band A (300 -

Peak power applied to BAND A

input connector should be between

-10 and +10 dBm for normal opera­tion.

+27 dBm or damage to the counter
may result,

is turned off.

(1) Perform the preliminary pro-

cedures of paragraph 2-7 b.

(2) Press the POWER switch to turn

off the counter.

(3) Select an address for the
counter by setting the GPIB IEEE STD
488/1975 ADDRESS SWITCHes 1 through 5

(fig. 2-8) in accordance with table 2-7.
Make sure that ADDRESS SWITCH 7 is set
to 0.

(4) Connect the GPIB controller to
counter with a GPIB cable and appropri­ate interface to the counter rear-panel
GPIB IEEE STD 488/1975 connector.

(5) Press the POWER switch to turn

on the counter.

(6) Apply power to the controller.
(7) Connect the signal source to

the BAND A input connector.

(8) Program REN (Remote Enable)

from the controller.

(9) Check that the counter front-

panel REMOTE indicator lights.

(10) Program BA to select Band A.

Execute.

(11) Select and program R4, R5, or

R6 for the desired resolution.

(12) If the input signal level is

high enough for counting, both the

Peak input must not exceed

Normal (TN).
Band B (BB).
Hold Passive (HP).

1 ms Gate Time

Resolution:

Fast Passive (FP).

Exponent-Scientific

Converter Auto (CA).

950 MHz) Operation.

CAUTION

even if the counter

10 kHz

Execute.

front-panel LEVEL and LOCK indicators

will light.

control to provide the desired display
update rate. The GATE indicator will
flash in accordance with the sample rate.
If the control is set to its switched

HOLD position,

the last reading. If a new reading is
desired, program CC to cycle counter.
Execute.

location,

the counter SAMPLE RATE control to
obtain a HOLD, retaining the last read-

ing,

Execute.

switching the counter SAMPLE RATE con­trol out of HOLD), program HP (Hold
Passive) to terminate the Hold Active.
Execute.

trol with ASCII SOH or with a
controller-unique command as appropri­ate.
have the REMOTE indicator off and
should be in the Local operation Off
Line modes.

Operation.

procedures of paragraph 2-7 b.

paragraph 2-15 h,

(9), except that in step (7) connect

the signal source to the BAND B input
connector.

(13) Turn the counter SAMPLE RATE

the display will retain

(14) If the counter is in a remote

the controller can override

To program a HOLD:

(a)

Program HA (Hold Active).

(b) To remove the HA (same as

(15) Program GTL (Go To Local) con-

Execute.

i. Band B (925 MHz - 18 GHz)

Peak power applied to the BAND B

Input connector should be within
the following ranges for normal
operation:

925 MHz - 10 GHz: -10 to +10 dBm

10 - 18 GHz:

The peak input power must not

exceed +30 dBm or damage to the
counter may result, even if the
counter is turned off.

(1) Initial Procedures.

(a)

(b) Perform procedures of

The counter should now

.

CAUTION

-5 to +10 dBm

Perform the preliminary

steps (2) through

2-24

(c)

Program BB to select

Band B.

Execute.

(d) Select and program R4, R5,
or R6 for the desired resolution.
Execute.

(e) If the input signal level

is high enough for counting, both the
front-panel LEVEL and LOCK indicators

will light.

If the REDUCE SIGNAL indi-

cator lights, the input signal power is

approaching the maximum safe operating

level and should be reduced.

(2) Automatic Mode. In the auto-

matic mode, the counter searches for the

input signal by sweeping from a start
frequency which is 105 MHz above a pre-

set frequency.

(a)

Program CA (Converter

Auto).

Execute.

NOTE

For full search, YP (YIG Preset)
is not programmed, which is
equivalent of setting the START
SWEEP thumbwheel switches to

00.0 GHz.

(b) To improve acquisition

speed, the sweep start frequency may be
set by programming YP (YIG Preset) fol­lowed by a number. The lowest frequency

which can then be acquired and displayed

or recorded will be 105 MHz above the

YIG Preset; erroneous readings may be

displayed or recorded if the applied
signal frequency is less than 105 MHz
above the YIG Preset.

(c)

To set the sweep start
frequency equivalency of thumbwheel
settings, program YP followed by a value
and scale factor.

Example:

for a start

frequency of 1.2 GHz, program YP 1.2 G

(mnemonic YP,

G).

Execute.

value 1.2, scale factor

(d) To reset the YIG Preset

frequency to 00.0 GHz, program YP G

(leaving out the value). Execute.

NOTE

To change the YIG Preset fre-

quency from one value to another,
or before resending the same

TM 11-6625-3031-14

value, YP must be set back to

00.0 GHz and the preset frequency
programmed.

(e)

Adjust the SAMPLE RATE
control or program as described in
paragraph 2-15 h, steps (13) through

(15).

(3) Manual Mode. In the manual

mode,

reducing the acquisition time.

the search sweep is inhibited,

However,

the signal frequency to be measured must
be between 105 and 325 MHz above the
preset frequency.

(a)

Program CM (Converter

Manual).

Execute.

(b)

Program YIG Preset, Value,
and Scale Factor to the desired fre­quency which must be 105 MHz to 325 MH

lower than the signal frequency.

ple:

if the expected measurement

Z

Exam-

frequency is 12.35 GHz, program
YP 12.2 G (which places the input fre­quency 105 to 325 MHz above the preset
frequency).

Execute.

NOTE

Erroneous readings may be dis­played or recorded if the
applied signal frequency is out-

side of the preset range.

(c)

Adjust the SAMPLE RATE
control or program as described in
paragraph 2-15 h, steps (13) through

(15).

j. Programming Example Using Calcu-

lator as Controller.

(1) A typical program, utilizing a
Hewlett-Packard 9815 Calculator as a
GPIB controller, is shown in table 2-9.
The program sets the counter as follows:

(a)

Band A (BA)

(b)

Remote Resolution - 10 kHz

(R4)

(c) 1 ms Gate Passive (TP)
(d)

Hold Passive (HP)

(e)

Fast Active (FA)

(f)

Exponent-Scientific (ES)

(g)

No YIG Preset (YPM)

(2) The program then instructs the

counter to take frequency readings and

2-25

TM 11-6625-3031-14

Table 2-9.

Program step

0000

0001

0003

0004

0005 END Clear COMMAND mode

0006 CMD 5 Enter COMMAND mode

0008

0009

0010

0011

0012

Typical Program Using Hewlett-Packard 9815

Calculator as Controller

Command

Clear

CMD 5

@

B

U

3

Blank

B

Clear counter

Controller to COMMAND mode

Set REN line active

Controller talk address

Counter listen address

Counter goes to data transfer mode

Device dependent data starts here

Comment

0013

0014

0015

0016

0017

0018

0019

0020

0021

0022

0023

0024

0025

A

R

4

T

P

H

P

F

A

E

S

Y

P

Counter set to Band A

Resolution 4

1 ms Gate Passive

Hold Passive

Fast Active

Exponent-Scientific

Clear YIG Preset

2-26

0026

M

TM 11-6625-3031-14

Table 2-9.

Typical Program Using Hewlett-Packard 9815

Calculator as Controller - Continued

Program step Command

0027 END

0028 Clear

0029

1

0030 Enter

0031

0032
0033

0034

0035

1

9

Read 5 Read frequency

Print

Go to 0028 Repeat

0036 END

Comment

End device dependent mode

prints out the results.

frequency of 580.75 MHz, the print-out

might appear as

For an input

An example of such an output, in which

the program sampled the frequency at
different resolutions and printed the

results, is
580750000
580760000
580740000
580760000
580760000
580750000

(3) The character E and exponent

values are not presented; however, this

is entirely dependent on the controller.
Although the information was sent, the
controller formatted and printed the
data in this form.

The way in which
output data may be interpreted, and
how data is sent to the counter, is

entirely dependent on the controller

used.

(4) Programs may be written to

display the entire data transmission.

RESOLUTION SCAN

. . . . . . . . . . . . . . .

285.24E6

285.1E6
285E6

285.2E6

. . . . . . . . . . .

OFFSET SHIFT

. . . . . . . . . . .

OEO

900E3

9.9E6

99.9E6

999.9E6

9.9999E9

2-27/(2-28 blank)

TM 11-6625-3031-14

CHAPTER 3

OPERATOR AND ORGANIZATIONAL MAINTENANCE

Section I. LUBRICATION

3-1.

Section II. TROUBLESHOOTING PROCEDURES

3-2.
malfunctions which you may find during
operation or maintenance of the

counter.

inspections and corrective actions in

the order listed.

Table 3-1 lists the common

You should perform the tests/

Table 3-1.

MALFUNCTION

TEST OR INSPECTION

1. No display

Step 1. Check if rear-panel fuse is blown.

- power not supplied to instrument.

No lubrication is required for the counter.

Operator and Organizational Troubleshooting

CORRECTIVE ACTION

Replace fuse with fuse of proper rating for operating voltage:

1.5 A slow-blow for 115 Vac,

3-3.

malfunctions that may occur, nor all

tests or inspections and corrective
actions.
or is not corrected by listed corrective
actions,

This manual cannot list all

If a malfunction is not listed

notify your supervisor.

or 0.75 A slow-blow for 230 Vac.

Step 2. Check that power cable is seated in rear-panel mounted

connector.

Seat power cable connector.

Step 3. Check power cable for open circuit and/or damaged connector

blades.

Replace power cable.

2. SAMPLE RATE control has no effect on display.

Step 1. Check that rear-panel mounted STORAGE and MIN. PRF switches

are both in down position.

Set STORAGE switch to ON and MIN. PRF switch to 50 Hz.

Step 2. Check GPIB IEEE STD 488/1975 ADDRESS SWITCHes.

Set ADDRESS SWITCHes 1 and 2 to 0 position (top pushed in).

3-1

TM 11-6625-3031-14

Table 3-1.

Operator and Organizational Troubleshooting - Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Step 3. Check that REMOTE indicator is not lighted.

If REMOTE indicator is lighted and GPIB controller is con-

nected,

Fast Active (FA) may be in control.

Program Fast
Passive (FP) and execute on GPIB controller to remove Fast
Active command. If programming and executing FP does not

correct,

Hold Active (HA) may be in control.

Program Hold
Passive (HP) and execute on GPIB controller to remove Hold
Active command.

3. RESOLUTION selector switches do not change display with signal source(s)
connected to input connector(s).

Step 1. Check that REMOTE indicator is not lighted.

If REMOTE indicator is lighted and GPIB controller is con­nected,

resolution commands R4,

R5, or R6 may be in control.

Program Go To Local Control (GTL) and execute.

4. Display shows incorrect or erratic reading for BAND A inputs.

Step 1. Check that LEVEL indicator is lighted.

CAUTION

Do not exceed +10 dBm peak power
input to the BAND A connector.

If not lighted,

increase signal level until LEVEL indicator

lights.

Step 2.

Press BAND A pushbutton firmly.

BAND A pushbuttons,

ending up with BAND A.

Cycle between BAND B and

Alternately selecting BAND A and BAND B pushbuttons may free
up contacts.

5. Display shows erroneous reading for BAND B inputs.

Step 1. Check PRESET FREQUENCY thumbwheel switch settings if in

MANUAL SELECT.

Setting must be 105 to 325 MHz below input

frequency.

Set thumbwheel switches to proper preset frequency.

Step 2. Check START FREQUENCY thumbwheel settings if in AUTO SWEEP mode.

Setting must be at least 105 MHz below input frequency.

3-2

Set thumbwheel switches to proper start frequency.

TM 11-6625-3031-14

Table 3-1.

MALFUNCTION

TEST OR INSPECTION

6. Counter does not count correctly with GPIB controller connected.

Step 1.

Operator and Organizational Troubleshooting - Continued

CORRECTIVE ACTION

Check that rear-panel ADDRESS SWITCH 7 is set to 0

(top pushed in).

Set ADDRESS SWITCH 7 to 0.
troller power.

POWER pushbutton and apply power to GPIB controller.

should remove microprocessor lock-up so that GPIB controller
can function.

Wait five seconds,

Remove counter power and con-

then press counter

This

Section III. MAINTENANCE PROCEDURES

3-4.

tenance is limited to inspection,
exterior cleaning, fuse and power cable
replacement, and performance of the
counter self-test.

3-5.

Introduction.

Operator and organizational main-

Inspection.

housing does not come off. Firm
but careful rotation of the fuse
puller will lift up one end of

the fuse so that finger force
can remove the fuse.
heed this caution by exerting

too much force may damage the
plastic pivot of the built-in
fuse puller.

Failure to

Inspection is accomplished by per­forming the preventive maintenance
checks listed in table 2-3.

3-6.

paragraph 2-5.

3-7.

follows:

of counter and slide plastic fuse cover

over power connector.

Cleaning.

Cleaning instructions appear in

Replacement.

a. Fuse.

(1) Disconnect power cable at rear

The FUSE PULL lever attached
the body of the power module

Replace a blown fuse as

CAUTION

to

(2) Remove installed fuse by lift-

ing up on FUSE PULL lever.

(3) Visually inspect fuse, or

check with an ohmmeter, to confirm that

it is blown.

(4) Reinstall original fuse (if not
blown) or replace defective fuse with
one of proper rating:

for 115 Vat, 0.75 A slow-blow for

230 Vat.

(5) Slide fuse cover over fuse and
reconnect power cable to connector.

b.

Power Cable.
is frayed or damaged, it must be
replaced.

3-8.

counter must be tested in accordance

with the procedures in paragraph 2-7 b.

Test.

After each maintenance action, the

1.5 A slow-blow

If the power cable

3-3/(3-4 blank)

TM 11-6625-3031-14

CHAPTER 4

DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE

Section I. REPAIR PARTS, SPECIAL TOOLS; TEST, MEASUREMENT, AND

DIAGNOSTIC EQUIPMENT (TMDE); AND SUPPORT EQUIPMENT

4-1.

equipment,
of Organization and Equipment (MTOE)
applicable to your unit.

4-2.
Equipment.

and support equipment are listed in the

Common Tools and

For authorized common tools and

refer to the Modified Table

Special Tools, TMDE, and Support

No special tools are required. TMDE

Equipment.

Section II. SERVICE UPON RECEIPT

4-4.
and prior
follow the assembly and preparation for

use instructions in paragraph 2-6. Be-

come familiar with the control settings

Upon receipt of the pulse counter

to performing maintenance

Section III. TROUBLESHOOTING

Maintenance Allocation Chart, Appendix B
of this manual.

4-3.

trated in the repair parts and special
tools list, TM 11-6625-3031-24P, cover-

ing direct support and general support

maintenance for this equipment.

and indicators by reviewing the operat­ing

graph 2-7.

following troubleshooting instructions.

Repair Parts.

Repair parts are listed and illus-

instructions

Then proceed with the

starting

with para-

4-5.

vided so that you can match what is
observed on the counter with the symptom
index and, from there, go to the page

in the troubleshooting table which
covers the malfunction. Use of the
counter operating controls and display
observation constitutes the initial

troubleshooting, followed by measure-

ments of increasing complexity.

should start with the obvious, for
example:
connections, improper seating or poor
connection of cables, etc.

Introduction.

a. Table 4-1, a symptom index, is pro-

b. Standard troubleshooting practice

blown fuses,

power and signal

After these

basic troubleshooting practices have
eliminated the obvious, then disassembly
or cover removal of the counter should
be considered.

SAFETY PRECAUTION

A periodic review of safety pre-

cautions in TB 385-4, Safety Pre­cautions for Maintenance of Elec­trical/Electronic Equipment, is
recommended.

is operated with covers removed,
DO NOT TOUCH exposed connections
or components.
are not grounded when making con­nections or adjusting components.

When the equipment

MAKE CERTAIN you

4-1

TM 11-6625-3031-14

DO NOT SERVICE OR ADJUST ALONE

Do not attempt internal service
or adjustment unless another per­son, capable of performing first
aid, is present.

c.

The troubleshooting table lists the
common malfunctions which you may find
during the operation or maintenance of

the counter or its components.

should perform the tests/inspections
and corrective actions in the order
listed.

d. This manual cannot list all mal-

functions that may occur, nor all tests
or inspections and corrective actions.

You

Table 4-1.

Symptom

If a malfunction is not listed or is not

corrected by listed corrective actions,

notify your supervisor.

NOTE

General Purpose Interface Bus

(GPIB) troubleshooting procedures
are in the depot maintenance work
requirements,
3031, for this equipment.

4-6.

1-3,
locations are shown in fig. 4-1.
out schematic diagrams are located in
the rear of this manual.

Symptom Index

Reference Diagrams.

Block diagrams are shown in fig. 1-2,

and 1-4.

CECOM DMWR 11-6625-

Subassembly and cable

Fold-

Troubleshooting

procedure

page

1. Display
No zeros
Display

DISPLAY
Display

200 MHz

Missing

Band A incorrect reading
Band B incorrect reading

2. LED Indicators
LEVEL indicator does not light.
LEVEL indicator blinks or lights continuously

without Band B input signal

LOCK indicator does not light
LOCK indicator blinks or lights continuously

without Band B input signal

GATE indicator does not light
REDUCE SIGNAL indicator does not light

does not indicate 88 888.88 when TEST
pushbutton is pressed

does not indicate 200 MHz when TEST
pushbutton is pressed

digit

4-4
4-4

4-6

4-6

4-7
4-8
4-10

4-13
4-13
4-14

4-15
4-15

4-15
4-16

4-2

TM 11-6625-3031-14

Figure

4-1.

Subassembly and Cable Locations

4-3

TM 11-6625-3031-14

MALFUNCTION

TEST OR INSPECTION

1. No zeros.

Step 1.

Step 2.

Table 4-2.

Direct Support and General Support

Troubleshooting

CORRECTIVE ACTION

Check if rear-panel fuse F1 is blown.

Replace fuse with fuse of proper rating for line operating
voltage:

1.5 A slow-blow for 115 Vac, 0.75 A slow-blow for

230 Vat.

NOTE

While inspecting fuse or replacing fuse make

sure that appropriate line voltage is visible
on voltage selector card under fuse post
housing.

Card should be seated so that it

does not interfere with slide protective

cover.

Check that power cable is seated in rear-panel connector.

Step 3.

Step 4.

Step 5.

Seat power cable.

Inspect power cable for physical damage.

Remove cable from

counter and check continuity.

Replace power cable.

Check that following cables are seated properly at both ends:

W22 from transformer T1 to Power Supply A107.
W17 from Display A110 to Counter Interconnect A100.

W14 from Display A110 to Count Chain Control A102.
W46 from Count Chain A103 to GPIB BCD Output AM120.
W47 from Count Chain A103 to GPIB BCD Output AM120.
W1 from Count Chain A103 to High Frequency A106.

Seat cable connections.

Place rear-panel MIN.

switch in ON position.

button.

If zeros now appear on display, Control A104 may be faulty.

PRF switch in 50 Hz position and STORAGE

Press and release front-panel RESET push-

Remove and replace Control A104.

4-4

Step 6.

Check cables W1, 46, and W47 for opens or shorts.

Replace defective cable.

TM 11-6625-3031-14

MALFUNCTION

TEST OR INSPECTION

Step 7.

Step 8.

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

CORRECTIVE ACTION

Check continuity of cables:

W17 and W14 from Display A110.

If open or shorted, replace Display A110.

W22 from transformer T1.

If open or shorted,

replace transformer T1.

Disconnect cable W27 from J8 on Counter Interconnect A100

(fig. 4-2).

Measure dc voltages between ground and pins of J8,
which should be +5 V at pin 1, -5.2 V at pin 2, +12 V at pin 3,
and -12 V at pin 4.

If one or more voltages are not as specified, proceed to step 9.
If all voltages are normal, remove and replace the following
circuit cards in sequence specified:

Count Chain Control A102
Count Chain A103

Step 9.

Step 10.

Step 11.

Control A104
Gate Generator A105
High Frequency A106
Display A110
GPIB Remote/Local Control AM121
GPIB BCD Output AM120.

Same as step 8.

Disconnect all circuit cards and cables, one at a time, until
abnormal voltage(s) are restored to correct level.

Replace

defective circuit card or module which caused fault.

Disconnect cable W22 from A107J1. Check for ac voltages on

cable connector:

18 volts ac between pin 1 (brown wire) and
pin 2 (red wire), 9 volts ac between pin 4 (yellow wire) and
pin 5 (green wire).

If ac voltages are normal, Power Supply

A107 may be faulty.

Replace Power Supply A107.

Remove protective cover from power module (31, fig. 4-3) and
check for following ac voltages on power module:

pins F to D,

115 volts ac; pins E to C, 115 volts ac. If ac voltages are

normal,

transformer T1 may be faulty.

Replace transformer assembly.

4-5

TM 11-6625-3031-14

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Step 12. Check for following ac voltages on power module:

pins J to B,

115 volts ac; pins L to N, 115 volts ac. If ac voltage on

pins L and N is normal,

and pushing and releasing POWER switch

several times does not place 115 volts on pins J and B, POWER

switch is faulty.

Replace POWER switch S101.

2. Display does not indicate 88 888.88 when TEST DISPLAY pushbutton is pressed.

Step 1.

Remove and replace Count Chain Control A102.

If 88 888.88 now
appears on display when TEST DISPLAY pushbutton is pressed,
original A102 was defective.

Replace Count Chain Control A102.

Step 2.

Using card extender,
Counter Interconnect A100.

elevate Count Chain Control A102 from

Jumper pins E and A on A102P1. If
88 888.88 now appears on display, TEST DISPLAY switch S2 on
Counter Interconnect A100 may be defective.

Replace Counter Interconnect A100.

Step 3.

Check that cables W14 from Display A110 to Count Chain Control

A102 and W17 from Display A110 to Counter Interconnect A100
are firmly seated.

Seat cable connections.

Step 4.

Check continuity of following cables:

W17 from Display A110.

If open or shorted,

replace Display A110.

W14 from Display A110.

If open or shorted,

replace Display A110.

3. Display does not indicate 200 MHz when TEST 200 MHz pushbutton is pressed.
Step 1. Remove and replace following circuit cards in sequence to fault

isolate by substitution.

After each substitution, press TEST

200 MHz switch and check display.
Control A104
Reference Oscillator Buffer A108
High Frequency A106

4-6

Gate Generator A105
Count Chain A103

TM 11-6625-3031-14

MALFUNCTION

TEST OR INSPECTION

Step 2. Ground pin 1 of TEST 200 MHz switch A100S1 (fig. 4-2). If

Step 3. Check that following cables are seated properly at both ends:

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

CORRECTIVE ACTION

Count Chain Control A102
Source/Amplifier A201.

Replace defective circuit card.

200 MHz now shows on display, switch may be defective.

Replace Counter Interconnect A100.

W18 from Counter Interconnect A100 to Converter Interconnect A200.
W9 from Source/Amplifier A201 to Gate Generator A105.
W2 from Gate Generator A105 to High Frequency A106.
W3 from Gate Generator A105 to High Frequency A106.
W1 from High Frequency A106 to Count Chain A103.
W14 from Display A110 to Count Chain Control A102.

Step 4. Check cables listed in step 3.

4. Missing digit.

Step 1. Remove and replace the following circuit cards in sequence to

fault isolate by substitution.

Count Chain Control A102

GPIB Remote/Local Control AM121

GPIB BCD Output AM120

Seat cable connections.

If W9 is open or shorted, replace cable.
If W18 is open or shorted,
If W2 is open or shorted,
If W3 is open or shorted,

replace Converter Interconnect A200.
replace Gate Generator A105.
replace Gate Generator A105.

If W1 is open or shorted, replace Count Chain A103.
If W14 is open or shorted, replace Display A110.

Display A110

Replace defective circuit card.

4-7

TM 11-6625-3031-14

MALFUNCTION

TEST OR INSPECTION

Step 2. Ground pin 1 on RESOLUTION switches A100S3 and A100S4 (fig. 4-2).

Step 3. Check that following cables are seated properly at both ends.

Step 4. Check cables W48, W54, and W55 for opens or shorts.

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

CORRECTIVE ACTION

Display will not show last two digits.

A100S3 and A100S4 in sequence.

Digits should appear as ground is

Unground pin 1 on switches

removed.

Replace Counter Interconnect A100.

W14 from Display A110 to Count Chain Control A102.
W54 from Interconnect A100 to GPIB Remote/Local Control AM121.
W55 from Interconnect A100 to GPIB Remote/Local Control AM121.
W48 from GPIB Remote/Local Control AM121 to GPIB BCD Output

AM120.

Seat cable connections.

Replace defective cable.

Step 5. Check cable W14 from Display A110.

If open or shorted,

5. Band A incorrect reading.
Step 1.

Check that rear-panel MIN. PRF switch is in 50 Hz position and

STORAGE switch is in ON position.

Place switches in correct positions.

Step 2.

Check that input signal is connected to Band A connector and that
BAND A selector switch is pressed in.

Connect and operate appropriately.

Step 3.

Check input signal frequency and level.

950 MHz at level between -10 dBm and +10 dBm.

Adjust input frequency and level.

Step 4.

If GPIB controller is connected to counter, check that REMOTE
indicator is not lighted.
are controlling counter.

Program Go To Local (GTL) from controller and execute to

return counter to local mode operation.

Step 5.

Check that LEVEL and LOCK indicators are lighted and GATE indicator
flashes at rate determined by SAMPLE RATE control setting.

replace Display A110.

Must be between 300 and

If lighted,

GPIB program commands

4-8

Replace Control A104.

TM 11-6625-3031-14

MALFUNCTION

TEST OR INSPECTION

Step 6. Check gate accuracy; see paragraph 4-8 c.

Step 7. Remove and replace following circuit cards in sequence to fault

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

CORRECTIVE ACTION

Adjust as required.

isolate by substitution:
Control A104
Prescaler A109
Reference Oscillator Buffer A108
Gate Generator A105

High Frequency A106

Count Chain Control A102
Count Chain A103
Dual Delay Line A116
GPIB Remote/Local Control A14121.

Replace defective circuit card.

NOTE

If High Frequency A106 card is replaced,
adjust in accordance with paragraph 4-8c.

—

Step 8. Check that following cables are seated properly at both ends:

W30 from BAND A connector A1J111 to Prescaler A109.

W34 from Prescaler A109 to Dual Delay Line A116.
W35 from Dual Delay Line A116 to High Frequency A106.
W33 from Prescaler A109 to Gate Generator A105.

W3 from Gate Generator A105 to High Frequency A106.

W1 from High Frequency A106 to Count Chain A103.

W54 from GPIB Remote/Local Control AM121 to Counter

Interconnect A100.
W55 from GPIB Remote/Local Control AM121 to Counter

Interconnect A100.

Seat cable connections.

Step 9. Check cables W30, W54, and W55 for opens or shorts.

Replace defective cable.

4-9

TM 11-6625-3031-14

Table 4-2. Direct Support and General Support

MALFUNCTION

TEST OR INSPECTION

Step 10. Check following cables:

W34 from Dual Delay Line A116

Troubleshooting - Continued

CORRECTIVE ACTION

If open or shorted,

W35 from Dual Delay Line A116

If open or shorted,

W33 from Prescaler A109

If open or shorted,

W3 from Gate Generator A105

If open or shorted,

W1 from Count Chain A103

If open or shorted,

6. Band B incorrect reading.

Step 1.

Check that rear-panel MIN.
and STORAGE switch is in ON position.

Place switches in correct positions.

Step 2.

Check that input signal is connected to BAND B connector and

that BAND B selector switch is pressed in.

Connect and operate appropriately

Step 3.

Check input signal frequency and level.

925 MHz and 18 GHz, with levels as follows: 925 MHz to

10 GHz, between

-5 dBm and +7 dbm.

replace Dual Delay Line A116.

replace Dual Delay Line A116.

replace Prescaler A109.

replace Gate Generator A105.

replace Count Chain A103.

PRF switch is in 50 Hz position

Must be between

-10 dBm and +7 dBm; 10 to 18 GHz, between

4-10

Step 4

0

Step 5.

Step 6.

Adjust input frequency and level.

Check that MANUAL SELECT/AUTO SWEEP switch is set to AUTO
SWEEP and START FREQUENCY thumbwheel switches are set to

00.0 GHz.
Place switches in proper positions.

Check that REDUCE SIGNAL indicator is not lighted or only

flashes occasionally.

Reduce signal level.

If GPIB controller is connected to counter,

indicator is not lighted.

If lighted, GPIB

check that REMOTE
program commands

are controlling counter.

TM 11-6625-3031-14

MALFUNCTION

TEST OR INSPECTION

Step 7.

Step 8.

Step 9.

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

CORRECTIVE ACTION

Program Go To Local (GTL) from controller and execute to

return counter to local mode operation.

Check that LEVEL and LOCK indicators are lighted and GATE

indicator flashes at rate determined by SAMPLE RATE control

setting.

Replace Control A104.

Check counter adjustments; see paragraph 4-8.

Adjust as required.

Remove and replace following in sequence to fault isolate

by substitution:

Control A104

Reference Oscillator Buffer A108
Prescaler A109
Count Chain Control A102

Count Chain A103
Gate Generator A105
High Frequency A106
Converter Sequencer A203

YIG Control A202

GPIB BCD Output AM120
GPIB Remote/Local Control AM121
Dual Delay Line A116
Source/Amplifier A201

Limiter/Attenuator A206

I.F. Processor A204

YIG Comb Generator A207.

Replace defective assembly.

NOTE

Adjustments specified in paragraph 4-8 are

required if any of the following are replaced:

High Frequency A106
YIG Control A202

4-11

TM 11-6625-3031-14

Table 4-2. Direct Support and General Support

MALFUNCTION

TEST OR INSPECTION

Step 10. Check that following cables are seated properly at both ends:

W1 from Count Chain A103 to High Frequency A106.
W3 from Gate Generator A105 to High Frequency A106.
W4 from Converter Interconnect A200 to Gate Generator A105.

Troubleshooting - Continued

CORRECTIVE ACTION

Converter Sequencer A203
I.F. Processor A204

Source/Amplifier A201
Limiter/Attenuator A206
YIG Comb Generator A207

If Reference Oscillator Buffer A108 is
replaced, recalibration is required.

W5 from Converter Interconnect A200 to I.F. Processor A204.
W6 from Converter Interconnect A200 to I.F. Processor A204.
W7 from Converter Interconnect A200 to I.F. Processor A204.

W8 from Converter Interconnect A200 to I.F. Processor A204.
W9 from Source/Amplifier A201 to Gate Generator A105.
W10 from Source/Amplifier A201 to YIG Comb Generator A207.
W11 from

W12 from

W13 from

W14 from

W15 from

W16 from

W17 from

W18 from

W19 from

W20 from

W21 from

W29 from

I.F. Processor A204 to Dual Delay Line A116.
Dual Delay Line A116 to High Frequency A106.
YIG Control A202 to Count Chain Control A102.
Count Chain Control A102 to Display A110.

thumbwheel switch to Counter Interconnect A100.
Source/Amplifier A201 to Converter Interconnect A200.

Display A110 to Counter Interconnect A100.

Counter Interconnect A100 to Converter Interconnect A200.

Converter Interconnect A100 to I.F. Processor A204.
Limiter/Attenuator A206 to Converter Sequencer A203.
YIG Control A202 to YIG Comb Generator A207.
YIG Comb Generator to Mixer A205.

.

4-12

W31 from

W54 from

I.F. Processor A204 to Prescaler A109.

Counter Interconnect A100 to GPIB Remote/Local

Control AM121.

TM 11-6625-3031-14

MALFUNCTION

TEST OR INSPECTION

Step 11. Check following cables:

Step 12. Check following cables:

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

CORRECTIVE ACTION

W55 from GPIB Remote/Local Control AM121 to Counter

Interconnect A100.

W56 from Counter Interconnect A100 to GPIB Remote/Local

Control AM121.

Seat cable connections.

W9, W10, W13, W21, W31, W54, W55, W56, and W29 for opens or

shorts.

Replace defective cable.

W1 from Count Chain A103.

If open or shorted, replace Count Chain A103.

W3 from Gate Generator A105.

If open or shorted, replace Gate Generator A105.

W4, W5, W6, W7, and W8 from Converter Interconnect A200.

If open or shorted, replace Converter Interconnect A200.

W11 and W12 from Dual Delay Line A116.

If open or shorted, replace Dual Delay Line A116.

W14 and W17 from Display A110.

If open or shorted, replace Display A110.

W15 from thumbwheel switch assembly.

If open or shorted,

W16 from Source/Amplifier A201.

If open or shorted, replace Source/Amplifier A201.

W19 from I.F. Processor A204.

If open or shorted, replace I.F. Processor A204.

W20 from Limiter/Attenuator A206.

If open or shorted,

7. LEVEL indicator does not light.

Step 1. Check level of input signal with power meter/thermistor mount.

Input level must be above -10 dBm for frequencies between 300 MHz

and 10 GHz, and above -5 dBm for frequencies between 10 and 18 GHz.

replace thumbwheel switch assembly.

replace Limiter/Attenuator A206

4-13

TM 11-6625-3031-14

MALFUNCTION

TEST OR INSPECTION

Step 2.

Step 3.

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

CORRECTIVE ACTION

Increase level of input signal, but not above +10 dBm between
300 MHz and 10 GHz, nor above +7 dBm between 10 to 18 GHz.

Check for +5 Vdc on pin 1 of W17P1, then jumper pin 6 (ground)
to pin 2.

LEVEL indicator should light.

Replace Display A110.

Remove and replace following in sequence to fault isolate by

substitution.
Control A104
Gate Generator A105

Prescaler A109 (if Band A inputs do not light LEVEL indicator)

I.F. Processor A204 (if Band B inputs do not light LEVEL
indicator).

Replace defective assembly.

Step 4.

Check that following cables are seated properly at both ends:
W17 from Display A110 to Counter Interconnect A100
W33 from Prescaler A109 to Gate Generator A105
W4 from Converter Interconnect A200 to Gate Generator A105
W5 from Converter Interconnect A200 to I.F. Processor A204.

Seat cable connections.

Step 5.

Check following cables:

W17 from Display A110.

If open or shorted,

replace Display A11O.

W33 from Prescaler A109.

If open or shorted,

replace Prescaler A109.

W4 and W5 from Converter Interconnect A200.

If open or shorted,

replace Converter Interconnect A200.

8. LEVEL indicator blinks or lights continuously without Band B input signal.
Step 1. Adjust in accordance with paragraphs 4-8 d

through f.

Replace Converter Sequencer A203.

4-14

Step 2. Repeat step 1.

Replace YIG Control A202.

TM 11-6625-3031-14

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

9. LOCK indicator does not light.

Step 1. Check for +5 Vdc on pin 1 of W17P1, then jumper pin 6 (ground)

to pin 3.

LOCK indicator should light.

Replace Display A110.

Step 2. Remove and replace following in sequence to fault isolate

by substitution:
Control A104
Converter Sequencer A203
I.F. Processor A204.

Replace defective assembly.

Step 3. Check that following cables are seated properly at both ends:

W17 from Display A110 to Counter Interconnect A100.
W18 from Converter Interconnect A200 to Counter Interconnect

A100.
W7 from Converter Interconnect A200 to I.F. Processor A204.

Seat cable connections.

Step 4. Check following cables:

W17 from Display A110.

If open or shorted,

replace Display A110.

W7 and W18 from Converter Interconnect A200.

If open or shorted,

replace Converter Interconnect A200.

10. LOCK indicator blinks or lights continuously without Band B input signal.

Step 1. Adjust in accordance with paragraphs 4-8 d

through f.

Replace Converter Sequencer A203.

Step 2. Repeat step 1.

Replace YIG Control A202.

11. GATE indicator does not light.

Step 1. Check for +5 Vdc on pin 1 of W17P1, then jumper pin 6 (ground)

to pin 4.

GATE indicator should light.

Replace Display A110.

4-15

TM 11-6625-3031-14

Table 4-2.

Direct Support and General Support

Troubleshooting - Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Step 2.

Remove and replace following in sequence to fault isolate

by substitution:

Control A104
Count Chain Control A102
Gate Generator A105.

Replace defective assembly.

Step 3.

Check that cable W17, between Display A110 and Counter
Interconnect A100, is seated properly.

Seat cable connections.

Step 4

Check cable W17.

0

If open or shorted, replace Display A110.

12. REDUCE SIGNAL indicator does not light.
NOTE

Step 1.

Step 2.

Step 3.

Step 4.

This indicator functions only on Band B

inputs and should light when input power

approaches the maximum safe operating level.

Check for approximately +0.5 Vdc on pin 14 of connector on W15.

Replace REDUCE SIGNAL indicator DS101 if voltage is present.

Remove and replace following in sequence to fault isolate
by substitution:

YIG Control A202

Converter Sequencer A203
GPIB Remote/Local Control AM121.

Check that following cables are seated properly at both ends:
W15 from thumbwheel switch assembly to Counter Interconnect A100.
W56 from Counter Interconnect A100 to GPIB Remote/Local

Control AM121.
W57 from GPIB Remote/Local Control AM121 to YIG Control A202.

Seat cable connections.

Check cables W56 and W57 for opens or shorts.

Replace defective cable.

4-16

Step 5.

Check cable W15 from thumbwheel switch assembly.

If open or shorted,

replace thumbwheel switch assembly.

TM 11-6625-3031-14

Figure 4-2.

Counter Interconnect A100, Connector and Switch Locations

Section IV. MAINTENANCE PROCEDURES

4-7.
Reassembly.

the interior of the counter is obtained
by removing the top and/or bottom
covers.
loosening the four screws which secure
it to the counter frame.
are held in place by a retainer (22,
fig. 4-3) which
screws (20) and

Disassembly, Replacement, and

a. General Instructions.

Each cover may be removed by

is secured by six
lockwashers (21).

Before proceeding with any fur-

ther disassembly, be sure the
counter is disconnected from the
ac power source.
high as 230 Vac may exist in the
counter.
DEATH may result from contact

with these potentials.

Always use an IC extractor to
disconnect ribbon cables to pre­vent damage to the connectors.

Serious injury or

Voltages as

CAUTION

Access to

Circuit cards

AM121.
must be removed from and reassembled In

event of failure.

covers from the counter.

fig. 4-3) and lockwashers (21) securing
retainer (22), and remove the retainer.

cables from AM120 (51) and AM121 (9).

washer (36), two studs (33), three nuts

secure circuit card AM120 (51) and
adapter (48) to rear panel assembly

lockwashers (27) which secure posts (28)
to the frame.

cards away from the rear panel and out
of the top of the counter.

flat washers (6), and lockwashers (7)

b. GPIB Circuit Cards AM120 and

Circuit cards AM120 and AM121

the counter as a single assembly,
although either may be replaced in the

(1) Disassembly.

(a) Remove the top and bottom

—

(b)

Remove six screws (20,

(c)

Disconnect the ribbon

(d)

Remove screw (37), lock-

(50), and three lockwashers (49) which

(42).

(e) Remove two screws (26) and

(f)

Pull assembled circuit

(g)

Remove two screws (5),

4-17

TM 11-6625-3031-14

1.

Spacer

2.

Fan assembly
Screw

3.

4.

Lockwasher

5.

Screw

6.

Flat washer

7.

Lockwasher

8.

Post

9. Circuit card AM121

10. Post

11. Lockwasher

12. Flat washer

13. Screw

14. Nut

15. Lockwasher

16.

Circuit card A100

17.

Flat washer

18.

Screw
POWER switch

19.

20.

Screw

21.

Lockwasher

22.

Retainer

23.

Side panel

24.

Screw

25.

Lockwasher

26.

Screw

27.

Lockwasher

4-18

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

Figure 4-3.

Post
Transformer assembly
Post
Power module
Post
Stud
Lockwasher
Screw
Lockwasher
Screw
Lockwasher
Screw

Counter,

Partial Exploded View

40.

Lockwasher

41.

Screw

42.

Rear panel assembly

43.

Lockwasher

44.

Screw
Lockwasher

45.

46.

Screw
Frame

47.

48.

Plate
Lockwasher

49.

50.

Nut

51.

Circuit card AM120

TM 11-6625-3031-14

to disassemble posts (8) from the
circuit cards.

(h) Remove four screws (13),

flat washers (12), and lockwashers (11)
holding the circuit cards together.
Separate the circuit cards, two posts

(8), and two posts (10).

(2) Reassembly.

(a) Assemble circuit cards (9

and 51), two posts (8), and two posts

(10).

(b) Secure the circuit cards

with four lockwashers (11), flat washers

(12), and screws (13).

(c)

Secure posts (28) to the
assembled circuit cards with two lock­washers (7), flat washers (6) and
screws (5).

(d)

Position the assembled
circuit cards so that the connector on
AM120 extends through the opening in the
rear panel.
place.

panel assembly (42) with lockwasher

(36), screw (37), and nut (50).

cuit cards to the rear panel assembly
with two studs (33), lockwashers (49),
and nuts (50).

frame with two lockwashers (27) and
screws (26).

cables to AM120 and AM121.

the frame and secure with six lock­washers (21) and screws (20).

covers.

c. Fan Assembly.

—

(1) Disassembly.

tom covers from the counter.

fig. 4-3) and lockwashers (21) secur­ing retainer (22), and remove the

retainer.

harness.

lockwashers (40) securing fan assembly

(2) and spacers (1) to rear panel assem-

bly (42).

Be sure plate (48) is in

(e) Secure plate (48) to rear

(f)

Secure the plate and cir-

(g)

Secure posts (28) to the

(h)

Reconnect the ribbon

(i)

Install retainer (22) on

(j)

Install the top and bottom

(a)

Remove the top and bot-

(b)

Remove six screws (20,

(c) Unplug the fan wiring

(d) Remove four screws (41) and

spacers forward and out of the top of
the counter.

lockwashers (4) securing two spacers

(1)

fan

(4)

and
and
and

harness.

secure it to

washers (21)

covers.

covers from the counter.

fig. 4-3) and lockwashers (21) securing
retainer (22) to the frame, and remove
the retainer.

lockwashers (43), from the top and

bottom, which secure two corner posts

(30) to frame (47).

lockwashers (45), from the top and

bottom, which secure post (32) to

frame (47).

and lockwashers (25), from the top and

bottom, which secure transformer assem­bly (29) to frame (47).

tom frame members to remove two rear
corner posts (30) and post (32).

from between the top and bottom frame

members.

lockwashers (15), flat washers (17),

and screws (18) which secure POWER
switch (19) to circuit card A100

(16).

the side panel opening.

Move the assembled fan and

(e)

(f)

Remove four screws (3) and

to the fan.

(2) Reassembly.

(a) Position two spacers (1) on

(2) and secure with four lockwashers

and screws (3).

(b)
spacers on rear panel assembly (42)
secure with four lockwashers (40)

screws (41).

(c)

(d)

(e)

d. Power Transformer.

—

(1) Disassembly.

(a) Remove the top and bottom

(b)

(c)

(d)

(e) Remove four screws (24)

(f)

(g)

(h)

(i) Remove the switch through

Remove the spacers.

Position the assembled fan

Connect the fan wiring

Install retainer (22) and
the frame with six lock-

and screws (20).

Install the top and bottom

Remove six screws (20,

Remove four screws (44) and

Remove two screws (46) and

Separate the top and bot-

Slide side panel (23)

Remove two nuts (14),

4-19

TM 11-6625-3031-14

(j)

Cut the cable ties holding

the switch wiring harness to the frame.

(k)

Remove two nuts (50), lock-

washers (49),

secure the connector on circuit card

(51) to rear panel assembly (42).

cables (fig. 4-1):

(42, fig. 4-3) from frame (47).

the inside cover on power module (31).
Remove the cover.

wiring from the power module.

bly (42).

wiring harness from Power Supply A107

(fig. 4-1) and remove transformer

assembly (29, fig. 4-3).

(2) Reassembly.

assembly (29) between the top and bot­tom frame members.

wiring harness into the receptacle on
A107 (fig. 4-1).

to power module (31, fig. 4-3).

cover and secure with a new cable tie.

assembly (42) in frame (47).

cables (fig. 4-1):

circuit card (51, fig. 4-3) to rear

and studs (33), which

(m)

Disconnect the following

W22 from A107J1
W23 from A108J1
W24 from A109J6
W25 from A106J6
W26 from A109J3
W27 from A100J8
W28 from A1OOJ1.

(n)

Remove rear panel assembly

(o)

Cut the cable tie securing

(p)

Tag and disconnect the

(q)

Remove rear panel assem-

(r) Unplug the transformer

(a) Position transformer

(b)

Plug the transformer

(c)

Connect the tagged leads

(d)

Install the power module

(e)

Position rear panel

(f)

Reconnect the following

W22 to A107J1
W23 to A108J1
W24 to A109J6
W25 to A106J6
W26 to A109J3
W27 to A100J8
W28 to A100J1.

(g)

Secure the connector on

panel assembly (42) with two studs (33),

lockwashers (49), and nuts (50).

Position POWER switch (19)

(h)
on circuit card (16) with the pushbutton
extended through the opening in the

front panel.

(i) Secure the switch to the
circuit card with the screws (18), flat
washers (17), lockwashers (15) and
nuts (14).

(j)

Install the switch wiring

harness to the frame with new cable

ties.

(k) Slide side panel (23)
through the channels between the top
and bottom frame members, being careful
not to damage the RFI shield braid.

(m)

Separate the top and bottom
frame members and install post (32) and
corner posts (30).

(n)

Secure post (32) with two

lockwashers (45) and screws (46).

(o)

Secure transformer assem-

bly (29) to the frame with four screws

(24) and lockwashers (25).

(p)

Secure two corner posts

(30) to the frame with four screws (44)

and lockwashers (43).

(q)

Install retainer (22) and
secure with six lockwashers (21) and
screws (20).

(r)

Install the top and bottom
covers.

4-8.

brightness of the LED displays may be

adjusted for the work area conditions
encountered. To adjust the brightness,
remove the top cover of the counter and
adjust resistor A102R35 on Count Chain
Control A102 (fig. 4-4).

A102R35 clockwise increases the display

brightness and counterclockwise
decreases the brightness.

tic Equipment Required.
equivalents) required for power supply
adjustments are:

AN/USM-451

Adjustments.

a.

Display Brightness. Relative

Turning

b.

Power Supply Voltages.

(1) Test, Measurement, and Diagnos-

TMDE (or

(a)

Oscilloscope OS-261/U

(b)

Multimeter, Digital

4-20

TM 11-6625-3031-14

Figure 4-4.

Adjustment Locations

(c) Transformer, Variable,

Staco 3PN501V

(2) Adjustment Procedure.

(a) Connect variable trans-

—

former to 115 Vac power line and adjust
for an output of 115 ± 1 Vac (114 to

116 Vac).

(b) Connect counter power

cable to variable transformer.

Apply
power to counter by pushing POWER
pushbutton on front panel.

Allow 20

minutes of warm-up time to stabilize

counter components.

(c)

Remove top cover and cir-

cuit card retainer.

NOTE

In the following procedures, do

not disconnect cable W18 from

A100J3 (fig. 4-2).

Connect test

equipment to A100J3, as speci-

fied, by inserting test leads

into mating connector of W18.

(d)

Connect negative lead of

digital multimeter and ground lead of
oscilloscope to pin 12 of A100J3.

(e)

Connect positive lead of

digital multimeter and oscilloscope
probe to each test point listed in

4-21

TM 11-6625-3031-14

table 4-3 and adjust the corresponding
control on Power Supply A107 (fig. 4-4)

to obtain the correct dc voltage.
peak-to-peak ripple voltage displayed
on the oscilloscope at each test point
should not exceed the maximum specified
in table 4-3.

(f)

Reduce the variable trans-

former output to 103.5 Vac.

voltages at each of the test points

listed in table 4-3. They must be

within the ranges specified.

(g)

Increase the variable

transformer output to 126.5 Vac and

again measure the voltages at each test
point to be certain that they remain
within tolerance.

(h)

Turn off counter, discon­nect test equipment, and reinstall
circuit card retainer and top cover.

c.

Gate Accuracy. This adjustment
affects Band A operation and is
required whenever High Frequency Cir­cuit Card A106 is replaced or when
adjustment is indicated as a trouble­shooting corrective action.

(1) Test, Measurement, and Diag­nostic Equipment Required. TMDE (or
equivalents) required for the gate
accuracy adjustment are:

(a)

Oscilloscope OS-261/U.

(b)

Multimeter, Digital

AN/USM-451.

(c)

Transformer, Variable,

Staco 3PN501V.

Measure the

The

Generator Subassembly

(d)

MX-8364A(P)/USM-308.

(e)

Generator Plug In PL-1242/

USM-308(V).

(f) Generator, Pulse SG-1105/U.
(g) Meter,
(h)

Thermistor Mount, Hewlett-

Packard 8478B.

(i)

Termination, Feedthrough,

Tektronix 011-0049-01.

(2) Adjustment Procedure.

(a)

Set counter controls as

follows:

SAMPLE RATE control Counterclockwise

RESOLUTION switches Both out

1 ms GATE switch
BAND A switch
MANUAL SELECT/AUTO AUTO SWEEP

SWEEP switch

Thumbwheel switches 00.0 GHz

(b)

Adjust power supply volt­ages as described in paragraph 4-8 b_ (2),
steps (a) through (g).

meter and oscilloscope, and reset
variable transformer output to 115 Vat.

assembly and plug-in for cw output at

950 MHz.

mistor mount, adjust cw output level to

-10 dBm.

output to vertical input of oscilloscope

—

(c) Disconnect digital volt-

(d)

Set sweep generator sub-

Using power meter and ther-

(e) Connect pulse generator

Power ME-441/U.

out
In

Test point

on A100J3

Pin 9

Pin 11

Pin 8

Pin 10

4-22

Table 4-3.

+5 V ± 10 mV

(+4.990 to +5.010 V)

+12 V ± 10 mV

(+11.990 to +12.010 V)

-12 V ± 10 mV
(-11.990 to -12.010 V)

-5.2 V ± 10 mV
(-5.190 to -5.210 V)

Power Supply Voltages and Adjustments

DC

voltage

Adjustment

control

A107R15

A107R7

A107R21

A107R31

Max. ripple

(mV pk-pk)

10

12

12

5

TM 11-6625-3031-14

through 50 ohm feedthrough termination;

termination must be attached directly
to oscilloscope input connector.
up pulse generator for 100 nanosecond
pulse width,

-1 volt output level (fig. 4-5).

generator and plug–in to BAND A connec­tor on counter.
displayed.

output to counter rear–panel INPUT
INHIBIT connector.
control so that you can read and record

10 or more displayed frequency readings
of the pulsed input.
of readings.

tained in step (g)
of cw frequency measured in step (f),

proceed directly to step (k).

wise, continue with step (i).

Example:
ured in step (f)
averaged frequency obtained in
step (g)

948.58 and 951.42 MHz.

(fig. 4-4) to minimize differences

between averaged pulse frequency and

cw frequency recorded in step (f).

50 kHz repetition rate, and

(f)

Connect output of sweep

Record cw frequency

(g) Connect pulse generator

Adjust SAMPLE RATE

Calculate average

(h)

If average frequency ob-

is within 1.42 MHz

NOTE

If cw frequency meas-

was 950.00 MHz,

should be between

(i)

Adjust resistor A106R60

Set

Other-

(j) Repeat step (g) to be sure

that average of pulsed frequencies is

within 1.42 MHz of cw frequency.

(k)

Turn off counter, discon-

nect test equipment, and reinstall

circuit card retainer and top cover.

NOTE

The adjustments which follow

affect Band B operation and must
be performed in the sequence
presented,
ments are dependent upon previous
ones.

in accordance with paragraph 4-8 g
after any adjustment is made.

Before making any adjustments,
check, and if necessary, adjust

the power supply voltages as
described in paragraph 4-8 b (2),
steps (a) through (e).

d. 40 kHz Clock.
40 kHz clock is required whenever YIG
Comb Generator A207 or Converter
Sequencer A203 is replaced, or when
adjustment is indicated as a trouble­shooting corrective action.

(1) Test, Measurement,
nostic Equipment Required.
equivalents) required for the 40 kHz

clock adjustments are:

(a)
(b) Extender, Card,

EIP 2020041.

(2) Adjustment Procedure.

(a) Set counter controls as

follows:

since some adjust-

The comb level must be set

Adjustment of the

and Diag­TMDE (or

Oscilloscope OS-261/U.

Figure 4-5.

Pulse Generator Output

BAND B switch
MANUAL SELECT/AUTO

SWEEP switch

Thumbwheel switches

(b)

Use card extender to

elevate YIG Control A202.

(c)

A202TP1 and A202TP3 (fig. 4-6).

A202TP5 and A202TP9 (ground).

channel 1 to pin 9 of A202U1.
5 V/div.

Connect jumper between

(d)

Connect jumper between

(e)

Connect oscilloscope

In
MANUAL SELECT

01.0 GHz

Set to

4-23

TM 11-6625-3031-14

Figure 4-6.

(f)

Connect oscilloscope
nel 2 to pin 4 of A202U1.
2 V/div.

(g) Apply power to counter.
(h) Adjust resistor A202R89 for

symmetrical waveform as shown in chan­nel 1 (upper) trace of fig. 4-7.
pulses in the train should be of equal
duration.
is the detected modulation pulse and
the 20 kHz reference is the channel 2

(lower) trace.

The leading and trailing edges of

the 20 kHz reference should be in
the center of the detected modu­lation pulse.
replace Converter Sequencer A203
and repeat step (h).

Slope and offset adjustments can
be made without any changes in

the existing test set-up, and are

normally accomplished after the

40 kHz clock adjustment. If the
40 kHz clock adjustments bring
the counter into normal opera­tion,
disconnecting the two jumpers
from test points installed in
steps (c)
card extender,
in the counter.

The channel 1 (upper) trace

complete the procedure by

and (d), remove the

YIG Control

Set to

NOTE

If they are not,

and reinstall A202

A202, Adjustment and Test Point Locations

chan-

All

YIG Comb Generator A207, Converter
Sequencer A203,

replaced,
cated as a troubleshooting corrective
action.

nostic Equipment Required. TMDE (or
equivalents) required for the slope and
offset adjustment are:

EIP 2020041.

adjustment:

oscilloscope leads from A202, change

or when adjustment is indi-

(1) Test, Measurement, and Diag-

(a) Oscilloscope OS-261/U.
(b)

(2) Adjustment Procedure.

(a) Perform 40 kHz clock

(b) Without removing jumpers or

or YIG Control A202 is

Extender, Card,

paragraph 4-8d(2).

e. Slope and Offset.

offset adjustment is required whenever

4-24

The slope and

Figure 4-7.

20 kHz Reference Pulse Timing

Detected Modulation and

TM 11-6625-3031-14

counter front-panel thumbwheel switch

setting in 1 GHz steps from 01.0

through 18.0 GHz and, at each setting,
adjust resistor A202R87 (fig. 4-4) for
symmetrical waveform (fig. 4-7).

(c)

Repeat steps (a) and (b) as

necessary to obtain symmetry on the

18 increments from 1 GHz through 18 GHz.

NOTE

Adjustment of A202R87 may affect

the previous 40 kHz adjustments.

Therefore,
be compensated for by readjust­ment of A202R89 for best possible

compromise.

to go back and forth between the

slope and offset adjustment

(A202R87) and the 40 kHz clock

adjustment (A202R89) to obtain

the best possible result.

(d)

probes.

(e) Disconnect test point

jumpers.

(f) Remove card extender and

reinstall A202 in counter.

f.

Attenuator Driver.

driver adjustments are required whenever
Converter Sequencer A203 or Limiter/

Attenuator A206 is replaced, when it is

known that the Band B input vswr is too
high, or when adjustment is indicated
as a troubleshooting corrective action.

(1) Test, Measurement, and Diag-

nostic Equipment Required.

equivalents) required for the attenuator

driver adjustments are:

(a)

(b)

MX-8364A(P)/USM-308.

(c) Generator,

PL-1304/USM-308(V).

(d) Generator,

PL-1242/USM-308(V).

(e)

(f)

Hewlett-Packard 8478B.

(g)

Hewlett-Packard 8491B-003.

(h)

Hewlett-Packard 423A.

this interaction must

It may be necessary

Disconnect oscilloscope

Attenuator

TMDE (or

Oscilloscope OS-261/U.

Generator Subassembly

Sweep, Plug In

Sweep, Plug In

Meter, Power ME-441/U.
Thermistor Mount,

Attenuator, Coaxial, Fixed,
Crystal Detector,

Hewlett-Packard 779D.

EIP 2020041.

and plug-in PL-1304/USM-308(V) for cw
output at 10 GHz.
thermistor mount,
to +7 dBm.

follows:
BAND B switch

MANUAL SELECT/AUTO

Thumbwheel switches

vate Converter Sequencer A203.

A203TP16 and A203TP21 (fig. 4-8).

as shown in fig. 4-9.
for maximum vertical sensitivity, dc
coupled.

for maximum return loss, as evidenced by

minimum dc level displayed on oscillo-

scope.
is shown in fig 4-10.

step (d).

Directional Coupler,

(i)

(j)

Extender, Card,

(2) Adjustment Procedure.

(a)

Set generator subassembly

Using power meter and

adjust cw output level

(b) Set counter controls as

In

AUTO SWEEP

SWEEP switch

00.0 GHz

(c)

Use card extender to ele-

(d)

Connect jumper between

(e)

Carefully set up equipment

Set oscilloscope

(f) Apply power to counter.
(g)

Adjust A203R44 (fig. 4-8)

A typical oscilloscope display

NOTE

As A203R44 is rotated from full

counterclockwise to full clock-

wise position,

played on the oscilloscope will

go from a maximum through a
minimum,
again.

for maximum return loss (minimum

reflected signal) corresponds to

the minimum dc level.

If the preceding adjustment was
made because A203 or A206 was
replaced, omit steps (i) and (j)
which follow, and continue
with the procedures in para­graph 4-8 f (3).

and then to a maximum

The correct adjustment

(h)

Remove jumper installed in

the dc level dis-

NOTE

4-25

TM 11-6625-3031-14

Figure 4-8.

Converter Sequencer A203,

Adjustment and Test Point Locations

(i), Turn off counter and dis-

connect test equipment.

(j)

Remove card extender and

reinstall A203 in counter.

(3) Attenuator Control Test. This

I

during first one to three steps of

attenuator control ramp (lower trace).
If I

test is required only if A203 or A206
has been replaced.

(a)

Temporarily connect a

0.47 µf capacitor across A203C2
(fig. 4-8).

(b) Connect oscilloscope chan-

nel 1 10X probe to pin 1 of A203J1

(fig. 4-8) to display I , and chan-

series

nel 2 10X probe to A203TP17 to display
attenuator control ramp.

(c)

Disconnect cable W8 (fig.
4-1) from A204J4 and ground center con­ductor of cable.

(d)

Connect jumper between

A203TP14 and A203TP16 (fig. 4-8).

A203TP14 and A203TP16, remove capacitor

connected across A203C2, and reconnect
cable W8 to A204J4.

and plug-in PL-1242/USM-308(V) for cw
output at 1.4 GHz.
and thermistor mount, adjust cw output

level to +5 dBm.

As shown in fig. 4-11,

(e)

series

(upper trace) should not change

series

changes, replace A203.

NOTE

If A203 is replaced, repeat steps

(a) through (e).

(f) Remove jumper between

(g)

Set generator subassembly

Using power meter

4-26

Figure 4-9.

Return Loss Measurement Setup

TM 11-6625-3031-14

Figure 4-10.

Measurement Waveform

(h)

Connect output of generator
subassembly and plug-in to counter
BAND B input.

(i) Adjust A203R21 (fig. 4-4)

until REDUCE SIGNAL indicator lights.

(j)

Press RESET switch and

readjust A203R21 as necessary.

(k)

Turn off counter and dis-

connect test equipment.

(m) Remove card extender and

reinstall A203 in counter.

g.

Comb Leveling. The comb leveling
adjustment is required if any of the
adjustments covered in paragraphs 4-8d

through f have been made.

(1) Test, Measurement, and Diag­nostic Equipment Required.
equivalents) required for comb leveling
are:

(a) Oscilloscope OS-261/U.
(b)

Extender, Card,

EIP 2020041.

(2) Adjustment Procedure.

(a) Set counter controls as

follows:

Return Loss

—

TMDE (or

Figure 4-11.

Control Ramp Offset

(c)

Connect A203TP14, A203TP15,

and A203TP16 (fig. 4-8) together.

probe to A203TP12 and connect external
trigger input to A203TP20.

comb line displayed on oscilloscope to

nominal 2 volt amplitude, as shown in

fig.

connect oscilloscope.

points on A203.

—

(d)

Connect oscilloscope 10x

(e) Apply power to counter.
(f) Adjust A203R90 to level

4-12.

(g) Turn off counter and dis-

(h) Remove jumpers from test

Typical Attenuator

BAND B switch
MANUAL SELECT/AUTO

SWEEP switch

Thumbwheel switches

(b) Use card extender to ele-

vate Converter Sequencer A203.

In

AUTO SWEEP

00.0 GHz

Figure 4-12.

Comb Line

4-27

TM 11-6625-3031-14

(i)

Remove card extender and BAND B switch

reinstall A203 in counter.

(j)

Reinstall circuit card

retainer and top cover.

In

MANUAL SELECT/AUTO AUTO SWEEP

SWEEP switch

Thumbwheel switches

00.0 GHz

4-9.

described in this section of the manual

is used to verify that the counter meets

its established specifications over the
entire frequency range, with both pulsed
and cw inputs.

tested in accordance with these pro-

cedures after replacement of any part or
assembly.

Equipment Required.
lent) required for the performance test
are:

Staco 3PN501V.

Hewlett-Packard 8478B.

MX-8364A(P)/USM-308.

USM-308(V).

USM-308(V).

PL-1304/USM-308(V).

Hewlett-Packard 8695A.

P281(*)-013.

Tektronix 011-0049-01.

TD-1209/U.

TD-1211/U.

follows:

POWER switch

SAMPLE RATE control

RESOLUTION switches

1 ms GATE switch

Performance Test.

a.

Purpose.

b. Test, Measurement and Diagnostic

(1) Transformer, Variable,

(2) Meter, Power ME-441/U.
(3) Thermistor Mount,

(4) Generator Subassembly

(5) Generator Plug In PL-1240A/

(6) Generator Plug In PL-1242/

(7) Generator,

(8) Oscillator,

(9) Adapter, Hewlett-Packard

(10) Termination, Feedthrough,

(11) Generator,
(12) Oscilloscope OS-261/U.

(13) Electronic Counter Mainframe

(14) Counter Module, Electronic

c. Initial Procedures.

—

(1) Set front-panel controls as

The performance test

The counter should be

TMDE (or equiva-

Sweep, Plug In

Sweep, Plug In,

Pulse SG-1105/U.

Off

Full
counterclockwise
Both out

Out

(2) Set rear-panel controls as

follows:

MIN. PRF switch

STORAGE switch
GPIB IEEE STD 488/

1975 ADDRESS

SWITCH

NOTE

See fig. 2-8 for explanation of
ADDRESS SWITCH positions.

(3) Connect variable transformer
to 115 Vac power line and adjust for
an output of 115 ± 1 Vac (114 to

116 Vac).

(4) Connect counter power cable to

variable transformer.

counter by pushing POWER switch on.

Allow 20 minutes of warm-up time to

stabilize counter components.

(5) Check for the following:

(a) Fan is blowing air out of

rear panel.

(b) Display shows all zeros.
(c) REDUCE SIGNAL indicator is

not lighted.

d. Self-test.

—

(1) Press TEST DISPLAY switch.
Display should indicate 88 888.88 while
switch is held in.

(2) Press TEST 200 MHz switch.
Display should indicate 200.00, with two

leading zeros blanked, while switch is

held in. Release switch.

(3) Press right RESOLUTION switch
and again hold TEST 200 MHz switch in.
Display should indicate 200.0, with two
leading zeros blanked. Release switch.

(4) While holding TEST 200 MHz
switch in,
output from 103.5 to 126.5 Vac.
must continue to show 200.00 over

entire line voltage range.

(5) Release TEST 200 MHz switch and

reset variable transformer output to

115 ± 1 Vac.

vary variable transformer

50 Hz

ON

1100000

Apply power to

Release switch.

Display

4-28

TM 11-6625-3031-14

CAUTION

Throughout the procedures which

follow, instructions are given to
set various signal sources to
specific output levels.
case,
measuring the output of the sig­nal source, before connecting it

to the counter,

tor mount and rf power meter.

If the signal source is in a
sweep mode,

be set at a slow speed to allow
monitoring the output power over

the sweep range.
should the output be allowed to
exceed the level specified for
each test step.

e.

—

and plug-in PL-1242/USM-308(V) for

-10 dBm cw output at 925 MHz.

BAND B input connector. Counter should

indicate input frequency of 925 MHz.

from full counterclockwise to full
clockwise positions, without actuating
HOLD switch, and observe LED indicators.
LEVEL and LOCK indicators should be
lighted continuously; GATE indicator

this must be done by

using a thermis-

the sweep rate must

In no case

Band B Response.

(1) Set up generator subassembly

(2) Connect generator and plug-in to

(3) Rotate SAMPLE RATE control

In each

should flash rapidly when SAMPLE RATE

control is near counterclockwise
extreme,
approaches clockwise limit.

fully clockwise until HOLD switch actu­ates.
Change generator frequency; counter
display should not change.

release.
new input frequency.
erator and plug-in from counter.

mid-point and push 1 ms GATE switch in.

to sweep from 0.925 to 2 GHz at low
power level of

table 4-4.
BAND B input connector and set sweep
time to permit counter to track swept

frequency.
correct frequency, without dropping
out,
range.
should not light during any portion
of sweep.

and change output to high level of

+10 dBm.

Counter should again display correct
frequency, without dropping out, over
entire swept frequency range.

and slowly as control

(4) Rotate SAMPLE RATE control

Display should hold last reading.

(5) Push RESET pushbutton and

Display should now change to

Disconnect gen-

(6) Turn SAMPLE RATE control to

(7) Adjust generator and plug-in

-10 dBm, as specified in

Reconnect plug-in to counter

Counter should display

over entire swept frequency

REDUCE SIGNAL indicator

(8) Disconnect plug-in from counter

Reconnect to BAND B connector.

Sweep

frequency

range

(GHz)

0.925 - 2
2

- 4
4-8
8-10

10 - 12.4

12.4 - 18

Table 4-4.

PL-1242/USM-308(V)
PL-1242/USM-308(V)

PL-1240A/USM-308(V)
PL-1304/USM-308(V)
PL-1304/USM-308(V)
Hewlett-Packard 8695A

with waveguide-to-

coax adapter

Band B Response Tests

Plug-in

Low
power
level

(dBm)

-10

-10

-10

-10

-5

-5

High
power
level

(dBm)

+10

+7
+7
+7
+7
+7

4-29

TM 11-6625-3031-14

NOTE

Periodic display hesitation will
be noticed.

At an input level approximately
+4 to +6 dBm at 1.4 GHz, the
REDUCE SIGNAL indicator should
be lighted.

(9) Repeat steps (7) and (8) for
each frequency range listed in table
4-4, using plug-in specified, at low
and high power levels shown in the
table.

(10) Disconnect plug-in from

counter.

f. Band B Gate Error.

(1) Reset counter front-panel

controls as follows:

RESOLUTION switches
SAMPLE RATE control

1 ms GATE switch

MANUAL SELECT/AUTO

SWEEP switch

Thumbwheel switches 01.0 GHz

(2) Set up generator subassembly

and plug-in PL-1242/USM-308(V) for

+7 dBm cw output at 1150 MHz.

(3) Connect pulse generator output
to vertical input of oscilloscope
through 50 ohm feedthrough termination;
termination must be attached directly
to oscilloscope input connector.
pulse generator for 100 nanosecond
pulse width,
and -1 volt output level (fig. 4-5).

(4) Connect plug-in to BAND B con­nector on counter.
and record cw frequency displayed.

(5) Connect pulse generator output
to counter rear-panel INPUT INHIBIT
connector.
so that you can read and record 10 or
more displayed frequency readings of the
pulsed input.

(6) Calculate average of readings
obtained in step (5). Average should
be within 570 kHz of cw frequency
measured in step (4).

50 kHz repetition rate,

Adjust SAMPLE RATE control

Both out
Full
counterclockwise
In

MANUAL SELECT

Set up

Press RESET switch

NOTE

Example:
ured in step (4) was 1150.00 MHz,
averaged frequency obtained in
step (6) should be between

1149.43 and 1150.57 MHz.

(7) Disconnect pulse generator from

INPUT INHIBIT connector.

The pulse generator must be dis­connected from the counter before
making measurements at a new
frequency to allow for frequency
stabilization.

(8) Repeat steps (4) through (7)

with +7 dBm cw output from plug-in at

the following frequencies:

1250 MHz, 1325 MHz, and 1350 MHz.

Do not change settings of pulse

generator or generator sub­assembly/plug-in controls at this
point.

g. 1 ms Gate.

(1) Set up generator subassembly

and plug-in for +7 dBm cw output at

1400 MHz.

(2) Connect plug-in to BAND B
connector and pulse generator to INPUT
INHIBIT connector.

(3) Connect rear-panel GATE OUT­PUT connector to vertical input of
oscilloscope through 50 ohm feed-

through termination; termination must

be attached directly to oscilloscope

input connector.

(4) Press 1 ms GATE time switch

on counter.

(5) Verify that a 1 millisecond

low-going pulse is displayed, going from
0 Vdc to less than -0.5 Vdc.

(6) Push right-hand RESOLUTION

switch.

(7) Verify that a 100 microsecond

low-going pulse is displayed, going from

0 Vdc to less than -0.5 Vdc.

If cw frequency meas-

NOTE

1200 MHz,

NOTE

4-30

TM 11-6625-3031-14

NOTE

Do not disconnect test equipment

from counter at this point.

h.

Signal Threshold.

(1) Move cable from GATE OUTPUT
connector to SIGNAL THRESHOLD OUTPUT
connector.

(2) With counter displaying input

frequency, signal threshold output dis­played on oscilloscope should be less
than -0.5 Vdc.

(3) Remove Band B input signal.

(4) Verify that signal threshold
output signal goes to approximately
0 Vdc.

(5) Disconnect oscilloscope from
counter.

i. Preset Frequencies.

—

(1) Adjust generator and plug-in

for cw output of +7 dBm at 1.0 GHz.
Reconnect plug-in to counter BAND B
input connector.

(2) Set MANUAL SELECT/AUTO SWEEP

switch to MANUAL SELECT and set thumb-

wheel switches to 01.0 GHz, as specified

in table 4-5.
zeros.

(3) Increase input frequency.
Counter should start counting at approx­imately 1.105 GHz (105 MHz above thumb-

wheel setting).

Display should show all

frequency.
out at approximately 1.36 GHz (360 MHz
above thumbwheel setting).

wheel setting of 1.0 GHz.

should display all zeros.

switch to AUTO SWEEP.

change to some incorrect frequency.

Counter should again start counting

correctly at approximately 1.105 GHz and
continue to count all higher frequencies

correctly.

for all other thumbwheel switch settings
listed in table 4-5.
specified in the table, set up to pro-

vide +7 dBm cw output at thumbwheel

switch frequency.
at which counter should start counting
for each switch setting is also shown in
the table, along with MANUAL SELECT

drop-out frequency.

counter.

trols as follows:

1 ms GATE switch

BAND A switch

(4) Continue to increase input

Counter display should drop

(5) Lower input frequency to thumb-

Counter

(6) Set MANUAL SELECT/AUTO SWEEP

Display should

(7) Increase input frequency.

(8) Repeat steps (1) through (7)

Use plug-in,

Approximate frequency

(9) Disconnect plug-in from

j. Band A Response.

(1) Reset counter front-panel con-

Out

In

Thumbwheel

switch setting

(GHz)

01.0

01.2

01.4

01.8

02.0

04.0

08.0

10.0

Table 4-5. Preset Frequency Tests

Start count

Plug-in

PL-1242/USM-308(V)

PL-1240A/USM-308(V)

PL-1304/USM-308(V)

frequency

(GHz)

1.105

1.305

1.505

1.905

2.105

4.105

8.105

10.105

MANUAL SELECT

drop-out frequency

(GHz)

1.36

1.56

1.76

2.16

2.36

4.36

8.36

10.36

4-31

TM 11-6625-3031-14

(2) Adjust generator subassembly

and plug-in PL-1242/USM-308(V) to sweep

from 300 to 950 MHz at output level of

-10 dBm.
(3) Connect plug-in to counter

BAND A input connector and set sweep

time to permit counter to track swept
frequency.
rect frequency, without dropping out,

over entire swept frequency range.

(4) Disconnect plug-in from counter

and change output level to +10 dBm.
Reconnect to BAND A connector. Counter

should again display correct frequency,

without dropping out, over entire swept

frequency.

(5) Disconnect plug-in from

counter.

k. Band A Gate Error.

(1) Set up generator subassembly

and plug-in PL-1242/USM-308(V) for
+7 dBm cw output at 450 MHz.

(2) Connect pulse generator output

to vertical input of oscilloscope

through 50 ohm feedthrough termination;
termination must be attached directly to
oscilloscope input connector.
pulse generator for 100 nanosecond pulse
width, 50 kHz repetition rate, and -1
volt output level (fig. 4-5).

(3) Connect plug-in to BAND A con­nector on counter.
and record cw frequency displayed.

(4) Connect pulse generator output

to counter rear-panel INPUT INHIBIT con­nector.

that you can read and record 10 or more

displayed frequency readings of the

pulsed input.

(5) Calculate average of readings
obtained in step (4). Average should be
within 1.42 MHz of cw frequency measured

in step (3).

Counter should display cor-

Set up

Press RESET switch

Adjust SAMPLE RATE control so

INPUT INHIBIT connector.

with +7 dBm cw output from plug-in at

the following frequencies:
880 MHz, 925 MHz, and 950 MHz.

counter.

frequency must be measured with the

ambient temperature between 0° and 50°C

(32° and 122°F).

TD-1209/U with module TD-1211/U to

10 MHz OUTPUT connector on rear panel of

counter.

should be between 9.999980 and

10.000020 MHz.

able transformer to 103.5 Vac and allow

15 minutes for time base oscillator to
stabilize.
should be within 1 Hz of frequency
measured in step (1).

transformer output at 126.5 Vac.

all TMDE.

NOTE

Example:
ured in step (3) was 450.00 MHz,
averaged frequency obtained in
step (5) should be between 448.58
and 451.42 MHz.

(6) Disconnect pulse generator from

The pulse generator must be dis­connected from the counter before

making measurements at a new

frequency to allow for frequency
stabilization.

(7) Repeat steps (3) through (6)

(8) Disconnect plug-in from

m. Time Base Frequency. The time base

(1) Connect counter mainframe

(2) Reduce output voltage of vari-

(3) Repeat step (2) with variable

(4) Turn off counter and disconnect

If cw frequency meas-

NOTE

650 MHz,

Frequency of 10 MHz OUTPUT

10 MHz OUTPUT frequency

4-32

TM 11-6625-3031-14

Section V. PREPARATION FOR STORAGE OR SHIPMENT

4-10.

or shipment,
roll it up, and tie with a strip tie or

twine.

4-11.

in styrofoam posts or cushion the
counter with cells or pads fabricated of
styrofoam or corrugated fiberboard.

with the power cable and technical
manual, within a close-fitting, slotted,

corrugated box. Seal the closure with
gummed tape and blunt all corners of the

box.

moisture-vaporproof barrier, and heat-

seal the closure.
second close-fitting, slotted, cor­rugated fiberboard box and seal the

entire closure with water-resistant

tape or adhesive.

d. Overwrap the boxed equipment in

waterproof barrier material.

seal all joints, seams, and closures

Preparation of Equipment.

To prepare the counter for storage

disconnect the power cable,

Packing Instructions.

a.

Support the corners of the counter

b. Place the cushioned unit, together

c. Place the boxed counter within a

Then place within a

Completely

with adhesive or other suitable seal

equal in moisture resistance to that of
the body material.

place the equipment, packaged as de-

scribed above, within a close-fitting
cardboard shipping carton.
entire closure with water-resistant tape

or adhesive and mark the shipping carton

in accordance with MIL-STD-129.

the equipment, packaged as described in
step d,
inside with a 2-inch thickness of excel­sior compacted to 3 pounds per cubic
foot.

be lined with a waterproof bag. Strap

the shipping container with metal
straps and mark in accordance with

MIL-STD-129.

e.

For storage or domestic shipment,

Seal the

Prevent personnel injury when
applying or removing steel strap­ping by wearing heavy gloves and
protective eyewear.
dle packing cartons by the steel
strapping.

f. For overseas shipment only, place

within a nailed wooden box lined

The shipping container should not

Do not han-

4-33/(4-34 blank)

APPENDIX A

REFERENCES

TM 11-6625-3031-14

DA Pam 310-1

TB 43-0118

TB 43-180

TB 385-4

TM 11-6625-2735-14

TM 11-6625-2835-14&P

TM 11-6625-2953-14

Consolidated Index Army Pubs and Forms
Field Instructions for Painting and Preserving

Electronics Command Equipment Including Camouflage
Pattern Painting of Electrical Equipment Shelters

Calibration Requirements for the Maintenance of Army
Materiel.

Safety Precautions for Maintenance of Electrical/
Electronic Equipment

Operator’s, Organizational, Direct Support, and
General Support Maintenance Manual (Including Depot
Maintenance) for Oscilloscope 0S-261 (NSN 6625-00-

127-0079) (NAVELEX O967-LP-17O-1O9O; TO 33A1-13-498-1)

Operator’s,
General Support Maintenance Manual (Including Repair
Parts and Special Tools Lists) for Pulse Generator,
SG-1105/U (Hewlett-Packard Model 8013B) (NSN 6625-01­010-3524)

Operator’s, Organizational, Direct Support, and
General Support Maintenance Manual; Multimeter,
AN/USM-451 (NSN 6625-01-060-6804)

Organizational,

Direct Support, and

TM 38-750
TM 740-90-1
TM 750-244-2

The Army Maintenance Management System (TAMMS)
Administrative Storage of Equipment
Procedures for Destruction of Electronics Materiel

to Prevent Enemy Use (Electronics Command)

A-1/(A-2 blank)

APPENDIX B

MAINTENANCE ALLOCATION

Section I. INTRODUCTION

TM 11-6625-3031-14

B-1.

of the maintenance operations for

Counter, Pulse, Electronic TD-1338(V)1/

USM.

nance for specific maintenance functions

on repairable items and components and

the tools and equipment required to per-

form each function.
be used as an aid in planning mainte­nance operations.

B-2.

to and defined as follows:

ability of an item by comparing its phys-

ical, mechanical, and/or electrical char­acteristics with established standards

through examination.

and to detect incipient failure by

measuring the mechanical or electrical

characteristics of an item and comparing
those characteristics with prescribed
standards.

odically to keep an item in proper oper­ating condition, i.e., to clean (decon-

taminate), to preserve, to drain, to
paint, or to replenish fuel, lubricants,
hydraulic fluids, or compressed air
supplies.

scribed limits, by bringing into proper

or exact position, or by setting the op­erating characteristics to the specified
parameters.

ble elements of an item to bring about
optimum or desired performance.

cause corrections to be made or to be

General.

This appendix provides a summary

It authorizes categories of mainte-

This appendix may

Maintenance Function.

Maintenance functions will be limited

a.

Inspect.

b.

Test. To verify serviceability

c. Service. Operations required peri-

d. Adjust.

e. Align.

f.

Calibrate. To determine and

To determine the service-

To maintain, within pre-

To adjust specified varia-

adjusted on instruments or test measur-

ing and diagnostic equipments used in
precision measurement.
parisons of two instruments, one of
which is a certified standard of known
accuracy, to detect and adjust any dis­crepancy in the accuracy of the instru-

ment being compared.

g.
seating, or fixing into position an
item, part, module (component or assem­bly) in a manner to allow the proper
functioning of the equipment or system.

h.
a serviceable like type part, subassem­bly, or module (component or assembly)
for an unserviceable counterpart.

i.
tenance services (inspect, test, serv­ice, adjust,

or other maintenance actions (welding,

grinding, riveting, straightening, fac­ing, remachining, or resurfacing) to
restore serviceability to an item by
correcting specific damage, fault, mal­function, or failure in a part, sub-

assembly, module (component or assem­bly), end item, or system.

j.

(service/action) necessary to restore an
item to a completely serviceable/opera­tional condition as prescribed by main­tenance standards (i.e., DMWR) in ap-

propriate technical publications.
Overhaul is normally the highest degree
of maintenance performed by the Army.
Overhaul does not normally return an

item to like new condition.

k.

ices/actions necessary for the restora-

tion of unserviceable equipment to a
like new condition in accordance with
original manufacturing standards. Re­build is the highest degree of materiel
maintenance applied to Army equipment.
The rebuild operation includes the act

Consists of com-

Install. The act of emplacing,

Replace. The act of substituting

Repair. The application of main-

align, calibrate, replace)

Overhaul.

Rebuild.

That maintenance effort

Consists of those serv-

B-1

TM 11-6625-3031-14

of returning to zero those age measure-

ments (hours, miles, etc.) considered in

classifying Army equipments/components.

B-3.

lists group numbers, the purpose of
which is to identify components, assem­blies, subassemblies, and modules with

the next higher assembly.

Column 2 contains the noun names of com-

ponents, assemblies, subassemblies, and

modules for which maintenance is

authorized.

Column 3 lists the functions to be per-

formed on the item listed in column 2.

When items are listed without mainte-

nance functions, it is solely for pur­pose of having the group numbers in the

MAC and RPSTL coincide.

Column 4 specifies, by the listing of a
“work time” figure in the appropriate
subcolumn(s), the lowest level of main­tenance authorized to perform the func­tion listed in column 3.
represents the active time required to
perform that maintenance function at the
indicated category of maintenance. If

the number or complexity of the tasks
within the listed maintenance function
vary at different maintenance categories,
appropriate “work time” figures will be

shown for each category.
task-hours specified by the “work time”
figure represents the average time re-

quired to restore an item (assembly,

subassembly, component, module, end item
or system) to a serviceable condition
under typical field operating conditions.
This time includes preparation time,

troubleshooting time, and quality assur­ante/quality control time in addition to
the time required to perform the specif-

ic tasks identified for the maintenance

functions authorized in the maintenance
allocation chart.
4 are as follows:

Column Entries.

a.

Column 1, Group Number. Column 1

b. Column 2, Component/Assembly.

c.

Column 3, Maintenance Functions.

d.

Column 4, Maintenance Category.

This figure

The number of

Subcolumns of column

C - Operator/Crew

organizational

O-

F ­H - General Support
D -

e.
Column 5 specifies by code, those common
tool sets (not individual tools) and

special tools, test, and support equip-

ment required to perform the designated

function.

f. Column 6, Remarks. Column 6 con-

tains an alphabetic code which leads to
the remark in section IV, Remarks, which
is pertinent to the item opposite the
particular code.

B-4.
ments (Section III).

a. Tool or Test Equipment Reference

Code.

cide with the numbers used in the tools
and equipment column of the MAC. The
numbers indicate the applicable tool or

test equipment for the maintenance
functions.

b. Maintenance Category. The codes

in this column indicate the maintenance

category allocated the tool or test
equipment.

c.
the noun name and nomenclature of the
tools and test equipment required to

perform the maintenance functions.

d. National/NATO Stock Number. This

column lists the National/NATO stock

number of the specific tool or test

equipment.

e.
the manufacturer’s part number of the
tool followed by the Federal Supply Code
for manufacturers (5-digit) in

parentheses.

B-5.

a.

to the appropriate item in section II,

column 6.

b. Remarks. This column provides the

required explanatory information neces-

sary to clarify items appearing in
section II.

Direct Support

Depot

Column 5, Tools and Equipment.

Tool and Test Equipment Require-

The numbers in this column coin-

Nomenclature. This column lists

Tool Number. This column lists

Remarks (Section IV).

Reference Code. This code refers

B-2

TM 11-6625-3031-14

Section Il. MAINTENANCE ALLOCATION CHART FOR

COUNTER, PULSE, ELECTRONIC TD-1338(V)1/USM

(1)
GROUP
NUMBER

00

(2)

COMPONENT

ASSEMBLY

Counter, Pulse,
Electronic
TD-1338(V)1/USM

(3)

MAINTE-

NANCE

FUNCTION

Inspect

Test

Test

Test

Repair

Repair

Cali-

brate

(4)

MAINTENANCE CATEGORY

C

0.1

0.1

O F

0.1

H

1.0

0.8 0.8

D

1.0

0.5

(5)

TOOLS

AND

EQPT

1,2,3,4,6,
7,8,9,11,
12,13,14,
21,22,25,
26

4,8,11,14,

16,17,18

1,20

1,12,13,24

(6)

REMARKS

A

B

C

D

E

F

G

01

02

Counter, basic

Converter

Adjust

Adjust

Adjust

Adjust

Adjust

Adjust

Adjust

0.1

0.3

0.5

0.3

0.3

0.3

0.5

1

1,2,15,21

1,2,3,4,8,

11,14,15,

21,25

1,2,23

1,2,23

1,2,23

1,2,4,5,6,

8,10,11,14,

19,23

H

I

J

K

L

M

N

B-3

TM 11-6625-3031-14

Section III. TOOL AND TEST EQUIPMENT REQUIREMENTS FOR

COUNTER, PULSE, ELECTRONIC TD-1338(V)1/USM

TOOL OR

TEST
EQUIP.

REF
CODE

1

2

3

4

5

6

7

8

9
10
11

MAINTE-

NANCE

CATE­GORY

H,D
H,D
H,D Generator,
H,D Generator Subassembly

H,D

H,D Generator, Sweep, Plug In

H,D

H,D
H,D
H,D
H,D

Tool Kit, Electronic Equipment TK-105/G
Oscilloscope OS-261/U

MX-8364A(P)/USM-308
Coupler, Directional (Hewlett-Packard

779D)

PL-1304/USM-308(V)
Oscillator, Sweep, Plug In (Hewlett-

Packard 8695A)
Generator Plug In PL-1242/USM-308(V)
Generator Plug In PL-1240/USM-308(V)
Detector,

Meter, Power ME-441/U

NOMENCLATURE

Pulse SG-1105/U

Crystal (Hewlett-Packard 423A)

NATIONAL/NATO

STOCK NUMBER

5180-00-610-8177
6625-00-127-0079
6625-01-010-3524
6625-00-442-3470

6625-00-444-2327

6625-00-928-0368

6625-00-251-5212
6625-00-165-1263

6625-00-436-4883

TOOL
NUM-

BER

12
13
14
15
16
17

18

19

20
21
22
23
24
25

26

H,D
H,D
H,D Thermistor Mount (Hewlett-Packard 8478B)
H,D
D

D

D

H,D

H,D

H,D Transformer, Variable (Staco 3PN501V)

H,D

H,D

H,D Thermometer, Precision/Scientific, 0-50°C

H,D

H,D Adapter (Hewlett-Packard P281(*)-013)

Electronic Counter Mainframe TD-1209/U
Counter Module, Electronic TD-1211/U

Multimeter, Digital AN/USM-451

Computer, Desktop (Hewlett-Packard 9825A)
Interface, GPIB (Hewlett-Packard 98034A)
Cable, GPIB (Hewlett-Packard 10833(*))
Attenuator, Coaxial, Fixed (Hewlett-

Packard 8491B-003)
Tool, IC Extractor (Augat T114-1)

Generator, Delay (EIP 400)
Extender, Card (EIP 2020041)

Termination, Feedthrough (Tektronix

011-0049-01)

6625-00-024-7066
6625-00-298-9676

6625-00-168-0585

B-4

Section IV. REMARKS

TM 11-6625-3031-14

REFERENCE

CODE

A

B

C

D

E

F

G

H

I

J

K

REMARKS

Visual inspection

Self-test only

Test after replacing card or module

GPIB operational test

Repair by replacing fuse or power cable

Repair by replacing card or module

Reference oscillator calibration

Display brightness adjustment

Power supply voltage adjustment

Gate ramp adjustment

YIG comb line adjustment

L

M

N

40 kHz clock adjustment

Slope and offset adjustment

Attenuator driver adjustment

B-5/(B-6 blank)

TM 11-6625-3031-14

APPENDIX C

COMPONENTS OF END ITEM AND BASIC ISSUE ITEMS LISTS

Not applicable

C-1/(C-2 blank)

APPENDIX D

ADDITIONAL AUTHORIZATION LIST

Not applicable

TM 11-6625-3031-14

D-1/(D-2 blank)

TM 11-6625-3031-14

APPENDIX E

EXPENDABLE SUPPLIES AND MATERIALS LIST

Not applicable

E-1/(E-2 blank)