HP AM-4380/U 5261A Technical Manual

TECHNICAL MANUAL

OPERATOR’S, ORGANIZATIONAL,

DIRECT SUPPORT AND GENERAL SUPPORT

MAINTENANCE MANUAL

(INCLUDING REPAIR PARTS

AND SPECIAL TOOLS LIST)

FOR

VIDEO AMPLIFIER AM-4380/U

TM 11-6625-2906-1 4&P

(HEWLETT-PACKARD MODEL 5261A)

(NSN 6625-00-269-4593)

HEADQUARTERS, DEPARTMENT OF THE ARMY

8 OCTOBER 1980

A

This manual Includes copyright material reproduced by permission of the HEWLETT-PACKARD Company

TM 11-6625-2906-14&P

TECHNICAL MANUAL HEADQUARTERS

DEPARTMENT OF THE ARMY

NO. 11-6625-2906-14&P

You can improve this manual by recommending improvements using DA Form 2028-2 located in the back
of the manual. Simply tear out the self-addressed form, fill it out as shown on the sample, fold it where shown,
and drop it in the mail.

If there are no blank DA Forms 2028-2 in the back of your manual, use the standard DA Form 2028
(Recommended Changes to Publications and Blank Forms) and forward to Commander, US Army
Communications and Electronics Materiel Readiness Command, ATTN: DRSEL-ME--MQ, Fort Monmouth, NJ
07,03.

In either case a reply will be forwarded direct to you.

} Washington, DC, 8 October 1980

OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT AND

GENERAL SUPPORT MAINTENANCE MANUAL

(INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS)

FOR

VIDEO MIPLIFIER ,MI-4380/U

(HEWLETT - PACKARD)

MODEL 5261A

(NSN 6625-00-269-4595)

REPORTING OF ERRORS

SERIAL PREFIX: 1124A

This manual applies directly to HP Model 5261A
Video Amplifiers having serial number prefix 1124A.

This manual Is an authentication of the manufacturer’s commercial literature which. through usage, has been found to
cover the data required to operate and maintain this equipm ent. Since the manual was not prepared In accordance with
military specifications and AR 310-3, the format TV not ban structured to consider levels of maintenance.

i

TABLE OF CONTENTS

Model 5261 A

Section Page

0 0-1. Scope............................................ 0-1

0-2. Indexes of Publications................. 0-1

0-3. Forms and Records....................... 0-1

0-4. Reporting Equipment Improve-

ment Recommendations (EIR)..... 0-1

0-5. Administrative Storage................. 0-1

0-6. Destruction of Army

Electronics Materiel..................... 0-1

I GENERAL INFORNIATION....................1-1

1-1.Introduction....................................1-1

1-2.Description.....................................1-1

1-4.Instrument Identification................1-1

1-6.Accessory Supplied.......................1-1

1-8.Accessories Available....................1-1

II INSTALLATION.......................................2-1

2-1.Initial Inspection.............................2-1

2-3 Storage and Reshipment...............2-1

2-6.Installation......................................2-1

2-8.Cooling..........................................2-1

2-10.Power Requirement.......................2-1

2-12.Electrical Connections...................2-1

Section Page

IV PRINCIPLES OF OPERATION..............4-1

4-1. Introduction................................4-1

4-3. Preamplifier Assembly Al1.........4-1

4-5. Attenuator Switch Assembly A2 4-1

4-7. Video Amplifier Assembly A3....4-1

4-10. Output Amplifier Assembly A4...4-1

V MAINTENANCE......................................5-1

5-1. Introduction................................5-1

5-3. Test Equipment.........................5-1

5-5. Assembly Identification..............5-1

5-7. In-Cabinet Performance Check.5-1

5-9. Adjustments...............................5-1

5-10. High Frequency Response

Adjustments A3C4. A3Cll.......5-1

5-12. Output Meter Calibration . .5-1

5-14. Troubleshooting and Repair......5-3

5-15. Troubleshooting.........................5-3

5-17. Printed Circuit Component

Replacement...........................5-3

VI REPLACEABLE PARTS.........................6-3

6-1.Introduction.....................................6-4

6-4. Ordering Information.......................6-5

III OPERATION..........................................3-1

3-1.Model 5261A Controls...................3-1

3-3.Operating Procedure.....................3-1

3-5.Operation with Pulse Input Signals3-1

3-7.Operation with High Impedance....3-1

Probe........................................3-1

3-9.Video Amplifier Input Impedance...3-1

ii

APPENDIXES

Page

APPENDIX A. References .......................................................................... A-1

B. Components of End Item List........................................................B-1

C. Additional Authorization List .........................................................(N/A)

D. aintenance Allocation Chart

Section I. troduction ....................................................................................D-1

II. Maintenance Allocation Chart...........................................................D-3

III. Tools and Test Equipment

Requirements ................................................................D-4

E. Manual Change Information...........................................................E-1

LIST OF ILLUSTRATIONS

Figure Page

1-1.Model 5261A.............................................................................................1-0

3-1.Input Impedance vs. Input Frequency .......................................................3-1

3-2.Controls .............................................................................................3-2

3-3.Frequency Measurement with Model 5261A..............................................3-3

5-1.Schematic Diagram Notes..........................................................................5-5

5-2.Top View, Component Location .........................................................5-6

5-3.Bottom View, Component Location .........................................................5-7

5-4.Video Amplifier Schematic Diagram.........................................................5-7

Model 5261A

A-1. Top View, Component Location.........................................................E-3

A-2. Bottom View, Component Location......................................................E-4

A-3. Video Amplifier Schematic...................................................................E-5

A-4. Al Preamplifier, Component Location...................................................E-6

A-5. Video Amplifier Schematic...................................................................E-7

LIST OF TABLES

Table Page

1-1.Specifications.............................................................................................1-1

1-2.Accessories Available ......................................................................1-1

3-1.Frequency Resolution.................................................................................3-1

5-1.Recommended Test Equipment.................................................................5-0

5-2.In-Cabinet Performance Check..................................................................5-2

5-3.Troubleshooting..........................................................................................5-4

6-1.Reference Designation Index.....................................................................6-3

6-2.Replaceable Parts.......................................................................................6-5

6-3.Manufacturer’s Code List............................................................................6-7

iii

SECTION 0

INTRODUCTION

0-1. SCOPE.

a. This manual describes Video Amplifier AM-

4380/U (fig. 1-1) and provides maintenance
instructions. Throughout this manual, AM­4380/U is referred to as the Hewlett-Packard
(HP) Model 5261A Video Amplifier.

0-2. INDEXES OF PUBLICATIONS.

a. DA Pam 310-4.

Refer to the latest issue of
DA Pam 310-4 to determine whether there are new
editions, changes, or additional publications pertaining to
the equipment.

b. DA Pam 310-7.

Refer to DA Pam 310-7 to
determine whether there are modification work orders
(MWO’s) pertaining to the equipment.

0-3. FORMS AND RECORDS.

TM 11-6625-2906-14 & P

P4030.29A and DLAR 4145.8.

c. Disc repancy in Shipment Report (DISREP)

(SF 361).

Fill out and forward Discrepancy in Shipment
Report (DISREP) (SF 361) as prescribed in AR 55­38/NAVSUPINST 4610.33B/AFR 7518/MCO P4610.19C
and DLAR 4500.15.

0-4. REPORTING EQUIPMENT IMPROVEMENT

RECOMMENDATIONS (EIR).

EIR’s will be prepared using SF 368 (Quality Deficiency
Report). Instructions for preparing EIR’s are provided in
TN) 38-750, the Army Maintenance Management
System. ElR’s should be mailed direct to Commander,
US Army Communication and Electronics Materiel
Readiness Command, ATTN: DRSEL-NIE-NIQ, Fort
Monmouth, NJ 07703. A reply will be furnished direct to
you.

a. Reports of Maintenance and Unsatisfactory

Equipment.

Maintenance forms, records, and reports
which are to be used by maintenance personnel at all
maintenance levels are listed in and prescribed by TM
38-750.

b. Report of Packaging and Handling

Deficiencies.

Fill out and forward DD Form 6
(Packaging Improvement Report) as prescribed in AR
70058/NAVSUPINST 4030.29/AFR 71-13/MCO

0-5. ADMINISTRATIVE STORAGE.

Administrative storage of equipm ent issued to and used
by Army activities shall be in accordance with T%, 740­90-1 and paragraph 2-8.

0-6. DESTRUCTION OF ARMY ELECTRONICS

MATERIEL.

Destruction of Army electronics materiel to prevent
enemy use shall be in accordance with TM 750-244-2.

0-1

FIGURE 1-1. Model 5261A

Model 5261A

Section I

Figure 1-1

1-0

GENERAL INFORMATION

1-1. INTRODUCTION.
1-2. DESCRIPTION.

1-3. The Hewlett-Packard Model 5261A Video
Amplifier is a plug-in unit which increases the sensitivity
of the Model 52431,, 52451I, and 5: 345A Electronic
Counters. The Model 5261A provides for measurement
of signals as low as 1 millivolt over the fr equency range
of 10 cps to 20 Me (52431) or 50) Mc (52451,). The
input impedance is I megohm and may be increas ed to
1(0 megohms by using a 10: 1 divider probe (HP stock
no. I000: 3A) An output signal is available at the
OUTPITT 50-ohm connector for monitoring the Video
Amplifier output or for activating external instruments.
This signal is identical in frequency and amplitude to the
amplified signal supplied to the counter input circuit.

1-4. INSTRUMENT II)ENTIFICATION.
1-5. Hewlett-Packard uses a two-section serial

number mounted on the rear panel. Earlier instruments
use an eight-digit serial number (000-00000). The first
three digits are a serial prefix number; the last five digits
refer to the specific instrument. Later instr uments use a
nine-digit serial number (0000A00000).The first four
digits are the serial instrument. If the serial prefix on your
instrument does not appear on the title page of this
manual, there may be differences between the manual
prefix and the last five digits refer to the specific

TABLE 1-1. Specifications*

Model 5261A

Section I

Paragraphs 1-1 to 1-9

SECTION I

and your instrument. If there are differences, they will
be described in a change sheet included with the manual.

1-6. ACCESSORY SUPPLIED.
1-7. A 50 ohm, low microphonic cable HP

10507fi001, with BNC connectors is supplied in the
package with the Model 5261A.

1-8. ACCESSORIES AVAILABLE.

1-9. Table 1-2 lists the accessories available for the
Model 5261ilA Video Amplifier.

TABLE 1-2. Accessories Available

Description HP Stock No.

10:1 divider probe, 10 pf shunt 10003A

600V max., dc to 40 Mc
50-ohm feed-through termination 10100A
50-conductor extender cable 10506C
Plug-in adapter (for use with 5345A) 10509A

BANDWIDTH: 50 OHM OUTTPUT:

10 cps to 50 Mc with 5245I,; 10 cps to 20 Mc Separate BNC front panel output for oscillo­with 5243I,. scope monitoring or for driving external equip-

INPUT SENSITIVITY: ment; 50-ohm source impedance. On ampli-

1 mV to 300 mV rms. fier’s most sensitive attenuator range, 1 mV

rms at input results in at least 100 mV rms at

INPUT IMPEDANCE: auxiliary output into 50-ohm load. Maximum

Approximately I megohm, 15 pf shunt; undistorted output is 300 mV rms into 50-ohm
HP 10003A Probe increases impedance to 10 load.
megohms, 10 pf shunt.

ATTENUATOR RANGES: ACCESSORY FURNISHED:

1, 3, 10, :30, and 100 mV rms. HP 100I 3A 10:1 Probe, 10 pf shunt, 600 volts

maximum; HP 10100A 50-ohm Feed-thru
MAXIMUM INPUT Termination, 10506B Extender Cable, 10590A
100 volts dc, 5 volts rms (ranges: 1, 3, 10, Plug-In Adapter.
30, 100 mV).

MONITOR: WEIGHT:

Meter shows when the signal level is accept- Net 2 lbs (0,90 kg); shipping 8 lbs (3,8 kg).
able to the counter.

ACCURACY: POWER:

Retains accuracy of 5243L, 5245L, or 5345A Supplied by 5243I,, 5245L, or 5345A Electronic
Electronic Counters. Counters.

*When installed in the HP Model 5243L, 5245L, or 5345A Electronic Counters.

1-1/1-2

SECTION II

INSTALLATION

Model 5261A

Section II

Paragraphs 2-1 to 2-13

2-1. INITIAL INSPECTION.

2-2 As soon as the Model 5261A is received, ver ify
that the instrument is intact and as or dered. Inspect the
plug-in for any physical damage such as scratched panel,
broken knob, or bent connec tors. If damage is found,
refer to the warranty page at the rear of this manual and
Paragraph 2-5 for shipping and repackaging instructions.

2-3. STORAGE AND RESHIPMENT.

2-4. ENVIRONMENT. Conditions during storage
and shipment should be limited as follows:

a. Maximum temperature 167-F (75°C).
b. Minimum temperature -40-F (-40°C).

2-5. PACKAGING. To protect your instrument
during shipment or storage, use the best packaging
methods available. Your Hewlett-Packard field office
can provide materials similar to those used for original
factory packaging. Contract packaging com panies can
provide dependable custom packaging on short notice.

a. If possible. use the original container
designed for the instrument. O therwise, use a strong
carton (350 lb/sq inch bursting str ength) or wooden box
to house the instrument.

b. Wrap the instrument in heavy paper or
plastic before placing it in the shipping container.

should refer to an instrument by model num ber and the
full, eight-digit serial number.

2-6. INSTALLATION.

2-7. To install the Video Amplif ier in the c ompar tment
provided at the right side of the counter front panel,
proceed as follows:

a. Remove AC power from the counter by
rotating the SAMPLE RATE control lull counter
clockwise to POWER OFF.

b. Loosen locking screws on either side of the
plug-in compartm ent (or single locking sc rew on left side
by turning fully counterclockwise.

c. Remove blank filler panel Or plug-in unit
installed.

d. Slide the Model 5261A into the
compartment. Make certain the plug-in is properly
aligned and tighten the locking screws.

2-8. COOLING

2-9. Tile Video Amplifier plug- in unit is cooled by the
ventilation of the (hp) counter in which it is installed.
Refer to the Operating and Service Manual of the
Counter for cooling system maintenance instructions.

2-10. POWER REOUIREMENTS

c. Use plenty of packing material around all
sides of the instrument and protect the front panel with
cardboard strips.

d. Seal the package with strong tape or m etal

bands. Mark with "Delicate Instrument."

e. Refer to the warranty page at the rear of this
manual and check with your Hewlett-Packard field office
for shipping instructions. All correspondence

2-11. All voltages required to operate the Model
5261A are supplied by the circuits of the (hp) counter in
which the plug-in is installed.

2-12. ELECTRICAL CONNECTIONS.

2-13. The INPUT terminal on the front panel of the
plug-in (see Figure 3-2) provides the only connection for
the input signal. The front-panel OUTPUT 50 Ω
connector supplies the Video Amplifier output for
monitoring or external equipment. All connections to
the counter are completed through the 50-pin j ack at the
rear of the plug-in unit.

2-1/2-2

SECTION III

OPERATION

3-1. MOLEL 5261A CONTROLS.

3-2. Figure 3-2 indicates the functions of the
connectors, meter, and SENSITIVITY control on the
Model 5261A front panel.

3-3. OPERATING PROCEDURE.

3-4. The Video Amplifier plug-in unit is ac-coupled but
does not change any functions of the counter in which it
is installed. Using the plug-in, period, multi-period,
frequency, totalizing, and ratio measurements can be
performed with input signals as low as one millivolt. Since
the measurements can be made with or without the
Video Amplifier installed, only frequency measurement is
illustrated in Figure 3 3. For other measurement
procedures, see the Operating and Service Manual for
your Electronic Counter. Table 3-1 lists the frequency
resolution for all settings of the counter TIME BASE
control (Figure 3-3, item 3).

TABLE 3-1. Frequency Resolution

INPUT FREQUENCY = 11.1223344 Mc

TIME BASE Counter Display

Setting and Resolution
1 µs no display

1 µs 11. Mc
10 µs 11.1 Mc
.1 ms 11.12 Mc

1 ms 11122. kc
10 ms 11122.3 kc
.1 s 11122.33 kc
1 s 11122. 334 kc
10 s 11122. 3344 kc

3-5. OPERATION WITH PULSE INPUT SIGNALS.

3-6. The Video Amplifier is designed to amplify
sinusoidal input signals. However, pulse input signals
can be amplified if the output signal is monitored to
ensure a satisfactory output to the counter. Monitor the
signal at the OUTPUT 50Q connector with an
oscilloscope and set the Video Amplifier SENSITIVITY
control for a level which results in satisfactory counter
operation. Because the output level meter is an
average-responding device, it will read low with a pulse
input signal. Do not use the meter as an output level
indicator when amplifying pulses.

Model 5261A

Section III

Paragraphs 3-1 to 3-10

FIGURE 3-1. Input Impedance vs Input Frequency

3-7. OPERATION WITH HIGH IMPEDANCE PROBE

3-8. The (hp) 10003A 10:1 divider probe can be used
with the Video Amplifier. The 10:1 divider probe serves
to decrease the effects of resistive loading on the
external circuit at low frequencies. When using the
probe, Video Amplifier sensitivity is decreased by 1 10.
As a result the maximum sensitivity of the Video Amplifier
is 10 mv.

3-9. VIDEO AMPLIFIER INPUT IMPEDANCE.

3-10. As illustrated in Figure 3-1, Video Amplifier input
impedance decreases at higher frequencies.

This decrease is due to the capacitive loading effect of
the amplifier input Thus when a signal source of fixed
impedance is connected to the Video Amplifier INPUT, a
meter at the signal source will not indicate the correct
input level at the Video Amplifier. To avoid this error,
monitor the input level at the Video Amplifier input with an
RF Voltmeter such as the (hp) Model 411A to ensure a
satisfactory input level. The Video Amplifier input can
also be terminated in the signal source characteristic
impedance but at frequencies near 50 Mc capacitive
loading reduces the input impedance, the signal source
is no longer terminated in its characteristic impedance,
and a meter at the signal source is incorrec t. Thus, the
simplest method of ensuring a satisfactory input to the
Video Amplifier is to monitor the signal level at the Video
Amplifier input.

3-1

CONTROLS

Model 5261A

Section III

Figure 3-2

1. INPUT signal connector: apply a 1-100 mv AC signal

between 10 cps and 20 Mc (5243L) or 10 cps and 50
Mc (5245L).

2. SENSITIVITY control: calibrated in millivolts, this

control determines the sensitivity of the Video
Amplifier and is adjus ted to keep the signal output to
the Counter within limits acceptable to the Counter
input circuits as indicated on the OUTPUT LEVEL
meter.

FIGURE 3-2. Controls

3. O UTPUT LEVEL meter: m eter monitors the level of
the Video Amplifier output to the Counter. When
meter indicates in green portion of scale, Video
Amplifier output to Counter is satisfactory.

4. OUTPUT 50 Ω connector: when terminated in 50
ohms, the signal at this connector is identical in
frequency and amplitude to the Video Amplifier
output to the Counter.

05261-A-6

3-2

Model 5261A

Section III

Figure 3-2

1. Apply power to Counter and Video Amplifier by 5. Set Video Amplifier SENSITIVITY to 100 MV.
turning SAMPLE RATE control slightly clock­wise from POWER OFF position.

6. Connect signal to be measured to INPUT con-

2. Set Counter SENSITIVITY to PLUG IN. nector on Video Amplifier. DO NOT EXCEED

5 V rms.

3. Set TIME BASE to 10 ms.*

4. Set FUNCTION to FREQUENCY. 7. Vary SENSITIVITY control until OUTPUT

LEVEL meter reads in green portion of scale.
*TIME BASE setting may vary depending upon de­sired resolution of INPUT signal frequency (Table 8. Observe frequency of INPUT signal as displayed
3-1). by Counter.

05261-A-3

FIGURE 3-3. Frequency Measurement with Model 5261A

3-3/3-4

SECTION IV

PRINCIPLES OF OPERATION

4-1. INTRODUCTION.

4-2. The four functional s ections of the Model 5261A
are illustrated in Figure 5-4. The pr eamplifier, attenuator,
video amplifier, and output amplifier circuits are
combined to amplify AC signals as small as 1 millivolt
and provide a usable output level to the counter input
circuit. All dc voltages to operate the Model 5261A are
supplied from the counter in which the unit is installed.
These dc voltages are filtered by components on
Amplifier assem bly A4, which includes a series regulator
in the 15-volt line.

4-3. PREAMPLIFIER ASSEMBLY A1.

4-4. The preamplifier circuit consists of a nuvistor
cathode follower driving an emitter follower to provide a
high impedance input and a low impedance output.
Diodes A1CR1 and A1CR2 limit input signal peak s and
prevent damage to A1Q1. Resistor A1R4 limits A1Q1
gate current during overload. Capacitors A1C2, A1C3,
A1C4, and A1C5 filter variations from the dc voltage
lines.

4-5. ATTENUATOR SWITCH ASSEMBLY A2.

4-6. Resistive attenuator A2 reduces the input s ignal
and establishes the overall gain of the Video Amplifier.
The amount of attenuation inserted is controlled by the
Video Amplifier SENSITIVITY switch. RC networks
A2C2, A2R10, and A219, A2C1 are selected to improve
frequency response.

4-7. VIDEO AMPLIFIER ASSEMBLY A3.

4-8. The video amplifier consists of two amplifiers
with three transistors each and feedback and drift
compensation for gain s tability Feedback is pr ovided by
the RC combination of A3R5, A3C4, A3R13, A3C1 and
transistors A3Q3,A3Q6 in the feedback loops of the two
amplifiers. Drif t compens ation is also acc omplished with
the addition of A3Q3 and A3Q6. Positive feedback to
amplifier No. 2 from output amplifier A4Q4 increases
amplifier No. 2 gain at higher frequencies.

4-9. The addition of A3Q3 and A3Q6 in the feedback
loops of the two amplifiers pr ovides three functions: 1)
act as negative feedback amplifiers to reduce the gain
which reduces any drift caused by temperature changes
in the two-stage amplifiers; 2) maintain the am plifier gain
at low frequencies; and 3) filter r ipple on the -14 volt line,
in conjunction with A3C6 and A3C13.

Model 5261A

Section IV

Paragraphs 4-1 to 4-15

4-10. OUTPUT AMPLIFIER ASSEMBLY A4.

4-11. Output amplifier assembly A4 consists of: 1)
output amplifier circuit, 2) meter circuit: 3) plus 20volt
filter; and 4) series regulator. These four circuits are
discussed in Paragraphs 4-12 through 4-15.

4-12. OUTPUT AMPLIFIER. Emitter follower A4Q4
provides the amplified input signal to the counter via rear
panel plug P6, pin 1. This same signal is supplied to
OUTPUT 509 jack J2 for monitoring with an oscillosc ope
or application to other equipment. Positive feedback
from A4Q4 emitter to amplifier No. 2 in the video
amplifier assem bly increases the video am plifier gain at
higher frequencies. Capacitors A4C9 and A4C10 are
connected in parallel to improve the overall frequency
response.

4-13. METER CIRCUIT The signal atA4Q4 emitter is
rectified by A4C R2 and A4C R3 and filtered by A4C12.
This dc is supplied to OUTPUT LEVEL meter M1.
Capacitors A4C11 and A4C13 are connected in parallel
to improve the frequency response of the meter circuit.
Meter Cal potentiometer A4R13 provides an adj ustment
for calibrating the OUTPUT LEVEL meter(Paragraph 5-

12). Minus 15 volts is supplied to the meter cir cuit and
establishes a bias on diodes A4CR2, 3. This prevents
the meter indicating for very small output signals and
permits a meter indication in the green scale for ml
output signal greater than 100 millivolts. Diode A4CR4
acts to protect the meter during input signals greater than
100 mv. A4CR4 anode is clamped at about -1.5 volts,
which corresponds to approximately full scale. W hen
the rectified signal output exceeds this value, A4CR4
conducts and protects the meter.

4-14. PLUS 20 VOLT FILTER. Transistors A4Q1,
A4Q2, and associated components filter variations and
noise from the t 20-ivolt line. A voltage c hange at A4Q1
collector causes a change at A4Q2 base and A4Q2
changes conduction to oppose the variation. The
emitter-collector voltage drop across A4Q2 is
approximately 1 volt and the ,20 volts becomes t 19 volts
at the drain of FET A1Q1. Resistors A4R2 and A4R3
form a dc voltage divider to establish the quiescent
voltage at A4Q1 base. Capacitor A4C2 bypasses to
ground ac variations at A4Q1 base.

4-15. SERIES REGULATOR. Series regulator A4Q3
provides regulated -14 volts for the Model 5261Acircuits .
Breakdown diode A4CRI establishes a referenc e voltage
at A4Q3 base. When the -15 volts changes, A4Q3
senses this change through A4R4 and increases
conduction to oppose the change. Inductor A4L1
reduces high-frequency transients in the -14 volt
regulated output.

4-1

Model 5261A

Section V
Table 5-1

TABLE 5-1. Recommended Test Equipment

Instrument Type Required Use Instrument

Characteristics Recommended

Electronic Counter Provide power (hp) Model 5243L or

(hp) Model 5245L

DC Voltmeter

0 v to ± 25v;

Troubleshooting (hp) Model 412A

10 M Ω input impedance;
1% accuracy

AC Voltmeter 1 mv to 500 mv; Troubleshooting (hp) Model 403B

10 cps to 1 Mc; Circuit adjustment
2% accuracy

RF Millivoltmeter 1 mv to 500 mv; Troubleshooting; (hp) Model 411A with

500 kc to 50 Mc: Circuit adjustment (hp) 11025A Probe
3% accuracy (formerly (hp) 411A-21E)

Oscillator 10 cps to 100 kc; Troubleshooting; (hp) Model 200CD

1 mv to 500 mv Circuit adjustment

High Frequency 100 kc to 50 Mc: Troubleshooting; (hp) Model 606A

Signal Generator 1 mv- to 500 mv Circuit adjustment

Oscilloscope 10 cps to 10 Mc; Troubleshooting; (hp) Model 175A with

5 mv/cm (hp) Model 1752A

Coaxial Cable Low Microphonics Troubleshooting:; (hp) 10507A

Circuit adjustment;
Operation

Extender Cable 50-pin connectors; Permits operation (hp) 10506B

straight-through outside of counter
connections

Feed-through BNC to BNC; Troubleshooting: (hp) 10100A

Termination

50

Ω

Circuit adjustment (2 required)

DC Power Supply 100 vdc Performance Check (hp) 711A

5-0

SECTION V

MAINTENANCE

Model 5261A

Section V

Paragraphs 5-1 to 5-13

5-1. INTRODUCTION.

5-2. This section of the manual provides maintenance
and service information for the Model 5261A Video
Amplifier. Included are troubleshooting procedures, a
table of recommended test equipment, repair
information, and in-cabinet performance checks which
may be used to verify proper operation of the instrument.

5-3. TEST EQUIPMENT.

5-4. Recommended test equipment for checking
performance and troubleshooting is listed in Table 5-1.
Test instrum ents not listed that have specif ications equal
to or better than the required characteristics listed may
be used.

5-5. ASSEMBLY IDENTIFICATION.

5-6. Throughout this manual, printed circuit
assemblies are referred to by assembly number. For
example, the Video Amplifier Assem bly is referred to as
A3. Connections to pins of the 50-pin plug on the rear of
the instrument are referred to by the plug number and pin
number; for example, pin 1 is referred to as P6(1).

5-7. IN-CABINET PERFORMANCE CHECK.

5-8. The performance checks listed in Table 5-2
verify proper operation of circuits in the Video Amplifier
and may be used:

a. as part of an incoming inspection check of

instrument specifications;

b. periodically, for instruments in systems

where maximum reliability is of primary importance;

c. as part of a troubleshooting procedure to

locate malfunctioning circuits, and

d. after any repairs or adjustments, before

returning instrument to regular service.

5-9. ADJUSTMENTS.

5-10. HIGH FREQUENCY RESPONSE

ADJUSTMENTS A3C4, A3Cll.

5-11. Trimmer capacitors A3C4 and A3Cll in video
amplifier assembly A3 provide the only adjustments for
frequency response. Adjust these capacitors only when
the bandwidth check (Table 5-2, In-Cabinet Perfor mance
Checks)indicates the frequency response is outside the

±3 db limits. The access hole f or tuning A3C4 is on the
bottom of the instrum ent and A3Cll access hole is on the
left side. Use a plastic tuning wand for adjustments.
Adjust A3C4 and A3Cll as follows

counter by loosening lock screws and sliding unit out of

a. Remove Video Amplifier plug-in from

counter plug-in compartment.

b. Use ', 10506B extension cable and connect
Video Amplifier rear plug to counter lack inside plug-ln
compartment.

c. Set counter controls as follows:

SAMPLE RATE.............slightly cw out oA POW'ER O FF

SENSITIVITY ................ PLUG-IN

TIME BASE................... 1 MS

FUNCTION...................FREQUENCY

d. Set Video Amplifier SENSITIVITY to 3 MV.

e. Connect Model 411A RF Millivoltmeter
through (hp)10100A feed through termination to 50

Ω

OUTPUT.

f. Connect Model GOGA generator through
(hp)10100A feedthrough termination to Video Amplifier
INPUT. Set frequency to 1000 kc and adjust output level
for 150 mv indication on voltmeter (use -3 db mark as
reference).

g. Slowly change generator frequency from
500 kc to 60 Mc. If voltm eter indicates less than - 6 db or
more than 0 db. adjust A3C11 to bring the voltmeter
indication within these limits.

h. Set generator frequency to 30 Mc and it
voltmeter indication is less than -6 db or mor e than 0db,
adjust A3C4.

i. Repeat steps g and h until the voltmeter
indication is within the limits for both steps.

j. Slowly change generator frequency between
500 kc and 60 Mc. Observe that voltmeter indication
remains between -6 db and 0 db over this frequency
range.

5-12. OUTPUT METER CALIBRATION.
5-13. Meter Cal potentiometer A4R13 is located on

output amplifier assem bly A4 and is accessible fr om the
top when the Video Amplifier is outside the counter plug­in compartment. Adjust A4R13 as follows:

a. Perform operations indicated in Paragraph
5-11, steps a, b, and c.

b. Connect Model 200CD oscillator output to
the Video Amplifier INPUT. Set oscillator frequency to
100 kc.

c. Connect Model 403B voltmeter to the Video
Amplifier 50 Ω OUTPUT through ; 10100A feedthrough
termination.

5-1

1.BANDWIDTH: 10 cps to 50 Mc

Model 5261A

Section V
Table 5-2

TABLE 5-2. In-Cabinet Performance Checks

a. Set counter controls as follows:

SAMPLE RATE slightly clockwise out of POWER OFF
SENSITIVITY to PLUG-IN
TIME BASE to .1 MS
FUNCTION to FREQUENCY

b. Set Video Amplifier SENSITIVITY to 3 MV. Connect (hp) 10100A 50-ohm feedthrough terminations to INPUT

and OUTPUT

c Connect Model 200CD Oscillator output to Video Amplifier INPUT and Model 403B Voltmeter to 50 Ω

OUTPUT.
d. Adjust Oscillator frequency to 100 kc and for indication of 120 mv on Voltmeter (use -4 db line as reference).
e. Slowly change Oscillator frequency from 100kc to 10cps. Video Amplifier output level should remain between

- 7 db and -1 db limits.

f. Disconnect Model 200CD and connect Model 606A to Video Amplifier INPUT through the (hp)10100A

feedthrough termination. Disconnect Model 403B from OUTPUT and connect Model 411A RF Voltmeter.
g Set generator to 1000 kc and adjust output level for -4 db reference as in step d. Remove Voltmeter from

OUTPUT and connect to INPUT. Record input level for reference level.
h. Connect Voltmeter to 50 Ω OUTPUT and slowly change generator frequency from 1000 kc to 100 kc. Repeat

above 100 kc to 50 Mc. Connect Voltmeter to INPUT periodically to check reference level. Video Amplifier

output should remain between -7 db and -1 db limits.

2. INPUT SENSITIVITY. 1 mv to 300 mv rms.
a. Set Counter controls as in 1 a.

b. Set Video Amplifier SENSITIVITY to 1 MV
c. Connect (hp) 10100A feedthrough terminations to Video Amplifier INPUT and 50 Ω OUTPUT
d. Connect 200CD to INPUT and Model 403B Voltmeter to 50 Ω OUTPUT. Adjust Oscillator frequency to 100

kc and for indication of 100 mv on Voltmeter

e. Disconnect Voltmeter from 50 Ω OUTPUT and connect Oscilloscope to 50 Ω OUTPUT. Oscilloscope display

should be a sine wave with no clipping.
f. Connect Voltmeter to Oscillator output. Voltmeter should indicate less than 1 mv.
g Connect Voltmeter to 50 Ω OUTPUT.
h. Set Video Amplifier SENSITIVITY to 100 mv.
i. Connect Oscillator to INPUT and set to 100 kc.
j. Adjust Oscillator output for 300 mv indication on Voltmeter.
k. Observe that Counter correctly counts input frequency.

3. MAXIMUM INPUT: 5 volts rms, 100 vdc
a. Set counter controls as in 1 a.

b. Connect BNC tee to Video Amplifier INPUT, set Model 711A DC Power Supply for 100 volts, add 1 megohm

series resistor, and connect power supply to Video Amplifier.

c Use a 0.1 µ f, 200 wvdc capacitor and connect Oscillator and Voltmeter to INPUT. Set Oscillator for 100 kc

and 5 volts rms as indicated on Voltmeter.

d.. Observe that counter correctly displays input frequency. (cont’d)

5-2

TABLE 5-2. In-Cabinet Performance Checks (cont’d)

4. MONITOR: OUTPUT METER indicates acceptable signal level to Counter
a. Set Counter controls as in 1 a and Video Amplifier SENSITIVITY to 3 ’MV.

b. Set Oscillator to 100 kc and connect to Video Amplifier INPUT with 50-ohm termination.
c. Connect Voltmeter to 50 19 OUTPUT with 50-ohm feedthrough termination.
d Adjust Oscillator output level for 420 mv on Voltmeter
e. Observe that OUTPUT LEVEL meter indicates at right edge of green portion of scale and Counter correctly

displays input frequency.

g Observe that OUTPUT LEVEL meter indicates at left edge of green portion of scale and Counter correctly

displays input frequency.

5. ACCURACY: retains accuracy of Model 5243L or Model 5245L Electronic Counter.
a. Set Counter controls as in 1 a.

b. Set Oscillator frequency to 100 kc and connect to Video Amplifier INPUT.
c. Set Video Amplifier SENSITIVITY to 100 MV.
d. Connect Voltmeter to Oscillator output and set signal level to 100 mv.
e. Observe and record Counter display.
f. Set Counter SENSITIVITY to .1V. Disconnect Oscillator output from Video Amplifier INPUT and connect to

Counter AC SIGNAL INPUT.

g. Observe that Counter display corresponds with value recorded in step e.

6. AUXILIARY OUTPUT’

Model 5261A

Section V

Paragraphs 5-14 to 5-18

a. 50 Ω OUTPUT on front panel lor monitoring amplified signal to Counter or for driving external equipment

checked in 1 under BANDWIDTH specification check.

b. 1 mv signal at Video Amplifier INPUT provides at least 100 mv at 50 Ω OUTPUT, checked in 2 under INPUT

SENSITIVITY specification check.

c. Maximum undistorted output is 300 my into 50-ohhm load, checked in 2 under INPUT SENSITIVITY

specification check.

d. Set Video Amplifier SENSITIVITY to 100

MV. Adjust Oscillator output for 420 mv on Voltmeter.

e. OUTPUT LEVEL meter should indicate at

right edge of green scale. If not, adjust A4R13 for this
indication.

f. Adjust Oscillator output for OUTPUT LEVEL

indication at left edge of green scale. Voltm eter should
indicate not less than 100 mv.

5-14. TROUBLESHOOTING AND REPAIR.

5-15. TROUBLESHOOTING.
5-16. When operation or perform ance checks indicate

an instrument malfunction, refer to Table 5-3
(Troubleshooting) for the more common indications of
trouble and checks to isolate the trouble. After the
trouble has been isolated to a particular assembly or
stage, voltage and resistance checks can be made to
determine the defective component.

5-17. PRINTED CIRCUIT COMPONENT

REPLACEMENT.

5-18. Component lead holes in the Mode I 5261A
printed circuit boards have plated walls to ensure good
electrical contact between conductors on opposite sides
of the board. To prevent dam age to this plating and to
the replacement component, apply heat sparingly and
work carefully. The following replacement procedure is
recommended:

a. Remove defective component by applying
heat carefully to the component connection and lifting the
component from the board.

b. Melt solder in component lead holes. Use
clean dry soldering iron to remove excess s older. Clean
holes with toothpick or wooden splinter. Do not use
metal tool for cleaning. This may damage through-hole
plating.

c. Bend lead of replac ement c omponent to the
correct shape and insert component leads into
component lead holes. Using heat and solder sparingly,
solder

5-3

Model 5261A

Section V
Table 5-3

leads in place. Heat may be applied to either side of
board. A heat sink (longnose pliers, commercial heat­sink tweezers, etc.) should be used when replacing
transistors and diodes to prevent conducting excessive

the separation from the board of the round conductor
pads against board and solder replacement component
lead to conductor pads on both sides of the board.

d. Through-hole plating breaks are indicated by

heat from the soldering iron to the component.

TABLE 5-3. Troubleshooting

Trouble Symptom Possible Cause

No output to Counter or 50 Ω OUTPUT DC voltages from Counter, FET A1Q1 dead,
jack A4Q4 shorted, P6(1) or J2 shorted

Low Video Amplifier gain AQ1 weak, A3Q1-A3Q6 weak, A4R5 increased

value
Output low at frequencies near 10 cps A4C6 open, A1C1, A3R18 increased value
Output Iow at frequencies above 100 kc A2C1 changed value, high frequency trimmers

A3C4 and A3C11 not correctly adjusted
Output noisy A1Q1 noisy poor ground connection at P6(3),

A3C5 ,or A3C12 changed value

5-4

Model 5261A

Section V

Figure 5-1

FIGURE 5-1. Schematic Diagram Notes.

5-5

Model 5261A

Section V

Figure 5-2

FIGURE 5-2. Top View, Component Location

5-6

Model 5261A

FIGURE 5-3. Bottom View, Component Location

5-7

Model 5261A

Section V

Figure 5-3 and 5-4

FIGURE 5-4. Video Amplifier Schematic.

5-7/5-8

SECTION VI

Model 5261A
TABLE 6-1.
6-1. Reference Desgnation Index (Cont’d)
Reference
Demgnaon Stock No. Description #
A3C7 ;lot-C09uC:Fau Cpr ’.b.BF IUCVuCt
A3C6 (lG01-C£Ob C:O-. L.LC1 bLF 25bbCe

Xu

AIC9 elbC-Oi,u9oLaF
A3Co10Olo-ClakC:FXD *.k .°.2 L 2,t 25VLtL

A3ClII 1l -OG,*uCSlAN bUAS! .b-6.L *F 75tVC-o
A3CXl - FALTORY SELECTIL FARTITYP

5I2

A3
A3C13 UO16-006 C:FAu tLCI 1SbUet +AuvO-1O 15VLW
A3Ql 1654-CulTKAfhbIbI0Rl aINC,o
A3Q2 le5G-0o02 TRA,ebIb. iORNha4L5j
AQ03 185b-0u64 TNAN5ISI GR IftRhAIacIWh
ASuQ 145L-o1oT1n6,hIS4bI0 1I h. O
A3wu5 le5C-Cl,4TRAN5I S1O:iiNL45
A3Q6 15I-00C62? TnaNSI1,IF IaEW(aIAiI
A3SRl oeb3-u103 RsIFX C tF
A3R2 Ot63-2Z2b nKFXU C’MF 2.kh h* DLt 1/4.
A3R3 0683-202o RtIFu CuFF kiO& OhM5 54 1/A4
A3F4q 0757-A180 klFXu *,T FLM Jl.6 H0M 1* I,eo*
AR5S 1757-012A FRaI-Xu LT FLM 6eu OHMS i. 1I/,
A3R6 0683-4q7> RAIFASU PP 47O0 utw15- 1/Ae
A3R7 U683-2425 RIFXu LCMP 4sUs uHt 5L 1/4’
A3R8 0683-7525 R:FXA CuMP 7.5K ChM 5t l/qi
A5R9 Ot63-k?25 RIFXU LUCF 2.auLi Uh51 /4,.
A3RIO 0603-272D RaFAu Cp.P '7"G uhmb 5bl/4h
A3Rl te3-2025
A3RI2 757-1OibRIFXO MST FL"h i.6 OhM l 1/oes
A3RI3 u757-C126 NIFXu M.T FLMh oU utHnS 2t i/At
A3RLI 068C3-7kf Rf:FXU Cn,MP 47tt’ uHe S % 1/h
A3R15 0683­Aq052el-bob7 ASSYHOUIPUT AMPLIFlK 6OA4Rb
05061-20U5 bLANh P.ilhlLO CIHCUIT BOARL
A4C1 U100-0127 CIFXU LCR ILF L'a Lb5VD(
A4C2 J 180-0094CIFXL)O tLCT A1OUtr evCC5
A4C3 1Uo0-0127 CIFXU Crk ILF Uba gb¥DCA

A

qCq 0180-0105 CIFXL LtECT 5(,F 25vOC*
A4C5 0163-0127 CIFXU Can IlF AL4a >wDCw
A4C6 tldO--011O CIFAU ELECI 4uF
A4C7 ulbC-009b CIaXD CHn '.05UF 1IOVOCI
4C8vlu60-C127 C:FXu Cth ILF ",a 5VOCw
A4C9 0160-0127 CIFXb ClR ILF G0j ebVOCI
A4Cl0 'lbO
A4CII (jlbo-O4a Cs:FXUs aECT 2(b UFbVOCD
A4CI2 UlbO-0045 C:FXa ELECl g40 iF SVO
A4Cl3 u15-009bC:FXb CLt .0be IuOVGCC
A4CRi 1902-004% SEMICON UEvICt105u SILICui. JUNCTIhN
A4CR2 1910-oua2 SEMICON LGEICLDIOu10 GE SOUMA 6P1% ,3.5N
A4CR3 1910-002e SEIlCON OIEvICEILaOuE GE 100MA bPIV 3.5N5
A4CR4 191L-0016 SEMICON OEVICLUl1Cit GERpAIluk
A4LI9140-0143 CUILFAxu RF 3.) uH
See lit of bbreviations in introduction to this section
02058-2 6-3

UloO-CiA7 CIh>, CLh ItF et, L.VOCA

nIF

xu CLhP kbot uHMb 51 l/4

24D

-C

1aiCaFXus LLCi 25L KF

RaIFkt CTMP 4Qbu vHMS 5% I/4w

Cts u.uSF IuvOCtW

IL

AL VALLt GIV-c,

10s COh

+l

uO-O

*b !b Il4

IC

25bbC*

1eVUCs

DC

Model 5261A

Section VI

Nte

Sect

ion VI

Table 6-1
Table 6-1 Reference Desgn.tion Idex (Cont’d)

Reference ’
Designation tock No. Description Note

401Q 1851-0017 TA$hSIS1OR IIhN)4
A402 1851-0017 TRhANbISSIO0IkN13C4
A403 1t>0-C064 THANSI£1ORa~iLhhAN]IU

C11

Q0312Gi5-O

HEAT SINKIPCR .3

A404 iP54-0019 TRAN5ISIOoR:2Nk,8
A404 1205-001HEAT SIIKI:FCFQi,
A4RI vo83-Z2215 RaFXU CuMP 22O OEHMS 5 l/4*

A4R2 U6 83-5125 RIFXD CbMP blu, OHMS 5% 1/4n
A4R3 0683-1O45 HIFXU C%MP 1i0K OHMS 5% 1/4i
A4R4 0683-8215 RIFXD C%MP e2U GPMb 5s 1/4s
A£45 v683-1825 RrFXO CuMP 1801 OHMS 5% 1/4

A4R6 u758-0O6z Rr:FX MLT FLM awU OHMS 5t I/t%

ti

A4R7 U683-6205 RIFXO CAMF b

OMS 5s 1/4*
A4RB 0683-2015 RIFXD CAMP 200 OMES 51/lW
A4R9 U683-6kOb RIFxo C,MP e2 OHMS I* l/nt
A4RlO 0683-2015 RIFXD CQMP 200 CHMS 5% l/q4

Model 5261A

A4Ril 0683-3615 RIFXD CAMP 360 CHMS 5% li/4
A4Rl2 0683-3625 RIFxb CMPF 3600 OHM 5% 1/4*
A4RI2 - FACTORY SELECTLO PARTITYFICAL VALUL GIVEs

oV-

A4RI3 21

0331 R:VAN ta 5000 ChM 101 LIN i* MLTLI CAL.
A4R14 O683-562S RTFXU CMPF 5609 OHMS 53 1/4l
AqR5 0U683-202>RIFXU CIMP 2K ChM 5o 1/4l
CI 0150-0005 CIFXO CR C100U PF 253 50S0VCw
C3015U-0005 CIFXo CLR 1GOG IF -,* 5COVObC
C40156-0005 CIFXa CcH ltOb F- 45a DOuuuL*
C50160-0174 CIFXU Can G.47UF 80U 25vLC*

C60160-0174 CIFXO CcR C.47UF 80* 25VbC*
JI 1250-0171 CONNECTRAa6NC INPUI
J2 1250-010o CONNECTtRtahC CUTPUT 50 OHM
Ml 1120-0143 METERI2uO LA EDGE VILO
5040-0185 BEZEL: METER
MPI5261-600ASSY SHIELC COVER,*ITH 8kAIL
MP25261-0004 BRACKET:SHIELD MOUNTING
nF)05261-00 Q1DIAL SENSITIVITY
MP45265A-83A GUIDE:MOLDEC PLASTIC,4-1/2 IN.14-l/kIN
MI'5('1 -n201l1 1PANEL FRONT STANDARD tMINT GRAY)
MP'2;l-1i PANEIFR)NT II)IS('()NTINLUEr)p (lIGHT GRAY)
NP705261-0005 SHIELOIaOX17 IhN. X -1/2 IN.

h.

MP85262A-47A SPACERaKOUNL,7-/41N

L6 X i/4lN.CIA
MP905261-0007 BRACKETrMETER MOuNTING
P61251-0099 CONNLCT,R PALE b5 PIN
*1 05261-6002 CABLLiOTPLT. 1 Il. LONG
2 05261-6003 CABLE RLAR,t Ih. LONG
3 5243A-160 CA8LE,(hOUNhCON P6 PIN 26 AND 49
= See list of abbreviations in introduction to this section

6-4

Model 5261A Section VI

TABLE 6-2.

6-4. Replaceable Parts

Stock No. Description #Mfr. Mfr. Part No. [TQRS
0121-0048 CIVAR GLASS .8-8.5 PF 750Vuca 73899 ¥C9GW I i!

0130-0011 C:VTR CER 1.5-7 PF 284010130-O011[ 1 1
0140-C2C2 C:FXU MICA 15 FF 5% 5suvocC.04Obd OM1SClSOJ boOV1
015O-O0uCSC:FXU CER 10u0 PF 25*a gOVDt* 0422elTYPE LFS-l3 2

0150-0096 CrFXU CER 0o.5F iOOVb

UC0

Vl4/1i-TA8! 2
0160-0127 CIFXU CER IUF esa 25VDOf 562bv [C13 71
0160-0128 CIFXU CEk 2.2 F 20Cx 25VC ; 56289 5C1521 1

0160-0174 CIFXO CER 0.47UF g0o .5VUC.t56ab9 5CllA 2 1
0160-0196 CIFXo MICA 24P~ 5% 30V~VCWO64bodMISCc4OJ l 1

0160-0975 C:FXD CER .001UF 20(;, 75VDCW 12574 SSM-001-981 1
0170-0055 C:FXD MY O.1UF 20%ri 200VDCW 56289 192P(0402 1 [
0180-0045 ClFui ELECT 20 UF 25VDOC 56269 03269t2 1

016i0-C00o CIFXa ELECT lO0LF +lOUO-10a 1lS’Lk

56ct9

Usv17IAl 2 1
1l0-0094CIFXD ELECT t1UoF 25vsC 56289 3UL1U6Al11
0180-0105 C:FXD ELECT b0rF 25VDC. 56te9 597q41 3 1

5GO

0180-0114 CIFXU ELECT 4UF +1L00-10 250DC.562b9 3OU400

2uA4 I1

0180-2121 C:FXD EI,ECT 250 MF 12VDCW 56289 30D257G012I)H411

0180-0:37,4 C:FXD EI,ECT 10UF 20VI)CW 56289 150D106X90202-I)YS 1 1
0683-1035 k:FDU COKP 1OK CHMS 5* 1/4l 01121 Cd 1035 1 1
0663-1045 RIFXU COMP 100N OHS 5- 1/4%O0111,Cb 1045 31
683-1825RIFXU COMP 1h0O- HrS 5- 1/4- (il;iCI6 I i51 1
06e3-2015 R:IFs CO.P 2oC OHMS 5t i/4*

(,11L

CB 2o15 2 1
0683-2025 k:FXu COAP 2Roo. OHMS St 1/4. ,111i Cd 2.5 41
0o83-2215 R:FXL COPP 2ec0 nHM 5 1/4 011121 Cb 2215 1 1
0e83-?225 IaFrO COMP 2.2& H0 5- 1/4l 1)121 Co 2225 2] 1
0683-2425 H:FXD COrP 24C OPHMS 5- 1/4. (I114l C6 2S45 2 1
0683-2725 R:FX COMP 2700 OHMS ' I1 4W01121 CRB 271n 1
0683-3045 R.FXD COMP 300K OHMS 5<S 1 4W01121 CB 30451 1

0683-3o015 aIFX COMP 360 OHMS 5a l/4l U111ICb 3615 1
0683-3625 RIFXU COMP 3ot OH ph5 5 1/4.0112CB C 3625 1 1

0683-3925 R:FXD COMP 3900 OHMS So 1'W01121 CB 3925d 1
068:-47245 R:FXD COMP 4700 OHMS 5; 1 4W 01121 CB 4725
0683-5125 R:FXD COMP 5100 OHMS 5 1 4W

0111

CB 125 1

00683-5605 ar:l- Co60P 56 8M- 56 1/4w calakI C 5t t

ull2l

0683-5625 aIFYD CCOP StCu 3*rs >- 1/4.

Il

(663-6205 ataFrU COME 62 Lhi’i bi

/4l Olil Co 62t O5t 21

Cb 56,5 1

0683-7505 natFXs COkP 75 LhnS 5 1]/4*(’111 Cb 7s551 1
0683-7525 R:FXD COMP 1 MEGOHM 5'e 1/4W 01121 CB 7525 1 1
0683-8215 R:FXD COMP 820 OHMS 5'r 1/4W 01121 CB 8215 1i
0683-9lC5 a:F>D COPP 91 OhMS 5% 1/41W o(liCe 91g51 1
0757-0069 RIFXO MET FLM 121 OhM 1i 1/4% 197ul rF6C 1-02 I
0757-1i26 ! R:FrU ’IFT FLM o80 CiMS 2* 1/2* 7115 C cC 2 ]
0757-C176 k:Fra MET FL1Se9 CnM It l/-w 75012 CEb T-U 3 1
0757-C178 NIFLa r'ET FLr 14L OhM 1l l/h 7521, CEoT-C2 1
I0757-0179 naFXL MET FLM i9* OHM I* ll’ 75c4e CErT-L 11
0757-0180 R:F

0757-0344 R:FXD MET FLM 1 MEGOHM

C0

U758-

II2-CM1

62 krFXi MET FLm 2C OChMS 5* 1,/2 C7115 C 20 I 1

I3 PETE*Ci,( aiA El6e VIES 60741

XLE MET

FLm u1.6 ChM I* I6bt75042 CLAT-21

1’

1/4W 01121 CB 0344 1

liv1

1200-01-e6 SOCpET::tuUVIsETCHk 3 PIN 717b7 t3)-6-11--26 1
1205-0011 HEAT SI:rFCk *.3 9B7o. TXrF-t32-OZ5P I1
= See list of abbreviaions in introduction to this section
02058 -2

6-5

Section VI Model 5261A
Table 6-2

Table 6-2. Replaceable Parts (Cont’d)
Stock No. Description Mfr. Mfr. Part No.TQ RS

1205-0012 hEAT SIKIrFOI Q4 05ai HMODEL NF-Ul1 a I
1250-0102 CONNLCTOSHINC CUTPUT >O OHM 91737 7011 1 1
1250-0171 CONIECTOR:BNC INPUT 91737 11246 1 1

1251-0099 CONNECTOR:MALE 50 PIN o0266 57 10500 1 1
18b0-0062 TPANSISTORsGERMANIUM 2840, 1850-C062 3; 3
lSSriH--1N1l TKANSIST()R-FET 01295 2N5245 1
1850-0102 TRANSISTOR 2N2455 28480 1850-0101 2 2
1851-0017 TRANhISTOR32N1304 01295 2NI304 2 2
1854-0019 TRANSISTORI2N2

368

07263 5-5781 4 4
l.)1I4LV76l SEMIC’ON I)DEVICE-I)IOI)E SILICON 28480 1901-0376 ’ 2 1
1()2-S()-I(I SEMICO I)EVICE.I)IOD)ESI,IC(ON JTNCTION 28480 1902-0)40 1!

19l0-)1l)()11 SEMI(’ON I)EVICE T)IOI)E GERMANIUM 933:2 I)2:61 1;
1910-0022 SEMICCN DEVICEIDIOCE GE 100A 6FIV 3.5NS 284eoi1910-0022 22
1921-0015 ELECTRON TUBES 8U56 NUVISTOK TRIODT 86684 8056 1 1
2100-0331 RIVAR ** 5000 OHM 105 LIN IW METER CAL. 28460 2100--C331 I 1
3100-0404 SWITCh-ROTARY 2 SECT S POS 2848U0310G-CG40 I4 1

5040-0185 BEZEL: NMETER 28480 5040-0185 1
5261-0004 BhRACKET: SHIELD M3OUNTING 28480 5261-0004 1

5261-6008 ASSY SHIELD COVER,*ITH BRAID 28e80 5261-0008 1
9140-0183 COILIFXO RF 3,3 UH 2848U 9140-Cl43 I 1i
05261-0001 DIAL SENSITIVIIY 28480 05261-0001 1
0526 10005 SHIELDS60X,7 IhN. 3-1/2 IN. 28480 05261-0005 1
05261-0007 BRACKETIMETER MOUNTING 28480 05261-0007 1
021-2l1

_)4

BLANK

[NTEI) CIRCLUIT

PRI

BOARD 28480 05261-2004

05261-2059 B.LANK PRINTED CIRCUTIT BOARI) 28480 05261--009 1

I)

115261-2)11 PANELFRONT STANI)AR

(MINT GRAY) 28480 (5261-2011 1 1

05261-6001 CABLE ATTENUAToR 28480 05261-6001 1 1
o5261-6002 CABLEKOUTPUT. 10 IN. LONG 28460 05261-6002 11
05261-6003 CABLE REAR-4 IN. LONG 284801

05261-6003 1

05261-6004 ASSYSATTENUATOR SWITCH 28460105261-6004I

05261i-6(6 ASSY:VIDEO AMPI.IFIER BOARD 28480 052614006 I
(026-lC ASSY.OPUTPUT AMPLIFIER BOARD 284180 02614007 1
05261-t609 ASSY PREAMPLIFIER BOARD 28480 052614009 1

5243A-160 CABLETGROUND 2848U 5243A-160 1aj
5243A-160 CABLLtGROUNDeON P6 PIN 26 AND49 284680 5243A-16D 1;
5262A-47A SPACEPIROUND.7 I/8IN. LG X 8/4lh.DIA2884u 5262A-47A 4
5262A-83A GUIDE MOLDED PLASTIC 4-1/2 IN X4-1/2 IN 28*80 5262A-83A 1

See list of abbrevitions in introduction to this section

6-6

TABLE 6-3. Manufacturer’s Code List

Code No. Manufacturer Address

01121 Allen Bradley Co......................................................................................... Milwaukee, Wis.

01295 Texas Instruments, Inc., Transistor Products Div. ..........................................Dallas, Texas

02660 Amphenol-Borg Electronics Corp ......................................................................Chicago, Ill.

04062 Elmenco Products Co.................................................................................. New York, N.Y.

04222 Hi-Q Division of Aerovox .........................................................................Myrtle Beach, S.C.

05820 Wakefield Engineering Inc. ....................................................................... Wakefield, Mass.

07115 Corning Glass Works Electronic Components Dept. ...................................... Bradford, Pa.

07263 Fairchild Semiconductor Corp.............................................................Mountain View, Calif.

12574 Gulton Ind., Inc., Data System Div ..........................................................Albuquerque, N.M.

19701 Electra Manufacturing Co. .........................................................................Kansas City, Mo.

28480 Hewlett-Packard Co. ................................................................................... Palo Alto, Calif.

56289 Sprague Electric Co. ........................................................................... North Adams, Mass.

60741 Tripplett Electrical Inc......................................................................................Bluffton, Ohio

71785 Cinch Mfg. Corp. ............................................................................................... Chicago, Ill.

73899 JFI) Electronics Corp..................................................................................... Brooklyn, N.Y.

75042 International Resistance Co. ..................................................................... Philadelphia, Pa.

86684 Radio Corp. of America, RCA Electron Tube Div........................................... Harrison, N.J.

91418 Radio Materials Co............................................................................................. Chicago, Ill

91737 Gremar Mfg. Co., Inc. ............................................................................... Wakefield, Mass.

93332 Sylvania Electric Prod. Inc., Semiconductor Div. .......................................Woburn, Mass.

98978 International Electronic Research Corp........................................................ Burbank, Calif.

Model 5261A

Appendix
Table 6-3

6-7

Model 5261A

Appendix

Table 6-4

NATIONAL NATIONAL
PART STOCK PART STOCK
NUMBER FSCM NUMBER NUMBER FSCM NUMBER

D2361 93332 5961-00-954-9182 0757-0069 28480 5905-00-917-0567
D32696 56289 5910-00-080-1890 0757-0126 28480 5905-00-971-1650
S97441 56289 5910-00-809-3431 0757-0176 28480 5905-00-972-4901
VC9GW 73899 5910-00-683-7157 0757-0178 28480 5905-00-763-5243
0121R0048 28480 5910-00-683-7157 0757-0179 28480 5905-00-972-4905
0130-0011 28480 5910-00-780-7577 0757-0180 28480 5905-00-972-4907
0140-0202 28480 5910-00-852-2655 0757-0344 28480 5905-00-269-2629
0150-0005 28480 5910-00-839-3156 1120-0143 28480 6625-00-974-6089
0150-0096 28480 5910-00-247-7226 1200-0086 28480 5935-00-782-8388
0160 0127 28480 5910-00-809-5484 1205-0011 28480 5999-00-789-3794
0160-0128 28480 5910-00-057-3934 1250-0102 28480 5935-00-988-7758
0160-0174 28480 5910-00-234-9817 1251-0099 28480 5935-00-777-6395
0160-0196 28480 5910-00-920-0475 133-65-11-026 71785 5935-00-945-9824
0170-0055 28480 5910-00-797-9742 1850-0062 28480 5961-00-988-7630
0180-0045 28480 5910-00-080-1890 1850-0101 28480 5961-00-774-7318
0180-0061 28480 5910-00-916-8071 1850-0102 28480 5961-00-764-3164
0180-0094 28480 5910-00-082-5119 1851-0017 28480 5961-00-826-0799
0180-0105 28480 5910-00-809-3431 1855-0081 28480 5961-00-350-8299
0180-0114 28480 5910-00-9711652 1901-0376 28480 5961-00-790-7834
0180-0212 28480 5910-00-971-1653 1902-0040 28480 5961-00-059-1215
0180-0374 28480 5910-00-931-7050 1910-0016 28480 5961-00-954-9182
05261-6001 28480 5995-00-503-7441 1910-0022 28480 5961-00-690-9341
05261-6004 28480 5930-00-020-5162 192P10402 56289 5910-00-437-7645
05261-6007 28480 6625-00-971-1651 2N1304 01295 5961-00-826-0799
05261-6009 28480 6625-00-971-1646 2N5245 01295 5961-00-350-8299
0683-1035 28480 5905-00-998-1929 2100-0331 28480 5905-00-971-1656
0683-2015 28480 5905-00-683-2239 30D188A1 56289 5910-00-827-1209
0683-2025 28480 5905-00-686-3370 30D257G012DH4 56289 5910-00-814-4955
0683-2725 28480 5905-00-882-2723 3100-0404 28480 5930-00-974-6090
0683-5125 28480 5905-00-139-1642 5C11A 56289 5910-00-883-0838
0683-5625 28480 5905-00-691R0195 5C15 56289 5910-00-057-3934
0683-7525 28480 5905-00-056-0520 7011 91737 5935-00-089-3572

9140-0143 28480 5950-00-716-4085

6-8

TM 11-6625-2906-14&P

APPENDIX A

REFERENCES

DA Pam 310-4 Index of Technical Manuals, Technical Bulletins

Supply Manuals (Types 7, 8 and 9), Supply
Bulletins and Lubrication Orders.

DA Pam 310-7 US Army Equipment Index of Modification Work

Orders.

TB 43-180 Calibration Requirements for the Maintenance

of Army Materiel.

TM 11-6625-57?2-]4 Operator’s and Organizational Maintenance Manual:

for Generator, Signal AN’/GRH-50

TM 11-6625-602-12 Operator’s Organizational, Direct Support and

General Support Maintenance Manual, Including
Repair Parts and Special Tools List for Test
Set Telephone, AN/USM-181/U (HP-3550)

TM 11-6625-2953-14 Operator’s Organizational, Direct Support and

General Support Maintenance Manual: Multimeter

AN/USM-451.
TM 38-750 The Army Maintenance Management System (TAMMS).
TM 750-244-2 Procedures for Destruction of Electronics

Materiel to Prevent Enemy Use (Electronics

Command).
TM 11-6625-1614-15 Organizational, DS and GS, and Depot Maintenance

Manual, Hewlett-Packard Electronics Voltmeter,

Model 41OC.

A-1

APPENDIX B

COMPONENTS OF END ITEM LIST

SECTION I. INTRODUCTION

B-1. SCOPE

This appendix identifies integral components of and basic issue items for the Video Amplifier AM4-4380/U to help

you inventory items required for safe and efficient operation.
B-2. GENERAL

The components of the end item are depicted in figure 1-1 on page 1-0. These items comprise the AM-4380/U

and must be packed together whenever it is transferred or turned in.

B-1

TM 11-6625-2906-14&P

APPENIDIX C

Additional Authorization List

(Not Applicable)

C-1

TM 11-6625-2906-14&P

APPENDIX D

MAINTENANCE ALLOCATION

SECTION I. INTRODUCTION

D-1. General

This appendix provides a summary of the
maintenance operations for the AyL-4380/U. It
authorizes categories of maintenance for specific
maintenance functions on repairable items and
components and the tools and equipment required to
perform each f unction. This appendix may be used as
an aid in planning maintenance operations.

D-2. Maintenance Function

Maintenance functions will be limited to and de, ed as
follows:

a. Inspect.

an item by comparing its physical, mechanical, and/ or
electrical characteristics with established standards
through examination.

b. Test.

detect incipient failure by measuring the mechanical or
electrical characteristics of an item and compar ing those
characteristics with prescribed standards.

To determine the ser viceability of

To verify serviceability and to

TM 11-6625-2906-14&P

in precision measurem ent. Consists of comparisons of
two instruments, one of which is a certified standard of
known accuracy, to detect and adjust any discrepancy in
the accuracy of the instrument being compared.

g. Install.

fixing into position an item, part, module (c omponent or
assembly) in a manner to allow the pr oper functioning of
the equipment or system.

h. Replace.

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

i. Repair.

services (inspect, test, service, adjust, align, calibrate,
replace) or other maintenance actions (welding,
grinding, riveting, straightening, facing, remachining, or
resurfacing) to restore serviceability to an item by
correcting specif ic damage, fault, m alfunction, or failure
in a part, subassembly, module (component or
assembly), end item, or system

The act of emplacing, s eating, or

The act of substituting a

The application of maintenance

c. Service.

to keep an item in proper operating conditions, i.e., to
clean (decontaminate), to preserve, to drain, to paint, or
to replenish fuel, lubricants, hydraulic fluids, or
compressed air supplies.

d. Adjust

limits, by bringing into proper or exact position, or by

setting the operating characteristics to the specie’s
parameters.

e. Align.

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

f. Calibrate.

corrections , o be made or to be adjusted on instrum ents
or test measuring and diagnostic equipments used

Operations required periodically

To maintain, within prescribed

To adjust specified variable

To determine and cause

. Overhaul.

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

necessary for the restoration of unserviceable equipm ent
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 of returning to zero
those age measurements ( hours, miles , etc.) considered
in classifying Army equipments/ components.

D-1

That maintenance effort

Consists of those services actions

D-3. Column Entries

a. Column 1, Group Number.

group numbers, the purpose of which is to identify
components, assemblies, subassemblies, and modules
with the next higher assembly.

b. Column 2, Component/Assembly.

2 contains the noun names of components, assemblies,
subassemblies, and modules for which maintenance is
authorized.

. Column 3, Maintenance Functions.

c
3 lists the functions to be performed on the item listed in
column 2. When items are listed without maintenance
functions, it is solely for purpose of having the group
numbers in the MAC and RPSTL coincide.

d. Column 4, Maintenance Category.

specifies, by the listing of a "worktime" figure in the
appropriate subcolumn(s), the lowest level of
maintenance authorized to perform the function listed in
column 3. This figure 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 "worktime"
figures will be shown for each category. The number of
task-hours specified by the "worktime" figure represents
the average time required 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 assurance/quality
control time in addition to the time required to perform
the specific tasks identified for the maintenance
functions authorized in the maintenance allocation chart.
Subcolumns of column 4 are as follows:

C Operator/Crew

O Organizational

F Direct Support

H General Support

D Depot

Column 1 lists

Column

Column

Column 4

TM 11-6625-29061 L&?

e. Column 5, Tools and Equipment.

specifies by code, those common tool sets (not individual
tools) and special tools, test, and support equipment
required to perform the designated function.

f. Column 6, Remarks.

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

D-4. Tool and Test Equipment Requirement (sect
III)

Column 6 contains

Column

a. Tool or Test Equipment Reference Code.

The numbers in this column coincide 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.

column indicate the maintenance category allocated the
tool or test equipment.

c. Nomenclature.

name and nomenclature of the tools and the equipment
required to perform the maintenance functions.

This column lists the noun

d. National/NATO Stock Number.

column lists the National/NATO stock number of the
specified tool or test equipment.

e. Tool Number.

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

D-5. Remarks (sect IV)

This column lists the

a. Reference Code.

appropriate item in section II, column 6.

b. Remarks.

required explanatory information necessary to clarify
items appearing in section II.

This column provides the

The codes in this

This

This code refers to the

D-2

SECTION II. MAINTENANCE ALLOCATION CHART

FOR

VIDEO AMPLIFIER, AM-4380/U

(1) (2) (3) (4) (5) (6)

GROUP MAINTENANCE MAINTENANCE CATEGORY TOOLS AND
NUMBER COMPONENT ASSEMBLY FUNCTION C O F H D EQUIPMENTREMARKS

00 AM-4380/U Inspect .5 13 A

01 Preamplifier Assembly A1 Inspect .25 1, 3, 5, 7, A

02 Attenuator Switch Assembly A2 Inspect .25 A

03 Video Amplifier Assembly A3 Inspect .25 A

04 Output Amplifier Assembly A4 Inspect .25 A

05 50 Ohm Cable Inspect .1 A

Service .25 13 B
Test 2.0 1, 3, 5, 7, C

10
Adjust 2.0
Test 2.0 C
Repair 3.0

Calibrate * 3.0 1, 3, 5, 7, C

10
Overhaul 4.0

Test .5 10
Adjust .5
Repair 1.0

Test .5 3
Repair 1.0

Test .5 4, 5, 9, 10
Repair 1.0

Repair 1.0 4, 7
Test .5

Test .1

*Calibrate per In-Cabinet Performance
Check this technical manual, paragraph
5-7. There is no formal calibration
procedure.

D-3

SECTION III. TOOL AND TEST EQUIPMENT REQUIREMENTS

FOR

VIDEO AMPLIFIER, AM-4380/U

TOOL OR TEST

EQUIPMENT MAINTENANCE NATIONAL/NATO TOOL

REF CODE LEVEL NOMENCLATURE STOCK NUMBER NUMBER

1 H, D Frequency .Counter AN/USM-451, or HP8640B 4931-00-545-2344
2 H, D DC Voltmeter JF 887AB

3 H, D AC Voltmeter JF 887ABAN. HP 403B/35503 6625-00-727-4695
4 H, D RF Millivoltmeter HP 41OC 6625-00-969-4105
5 H, D Oscillator HP 200CD, HP 652A HP-606A 6625-00-575-7737

(AN/GRM-50) 4931-00-113-2943

6 H, D HF Signal Generator HP 8614A, 8640B 6625-00-495-4851

’ 4931-00-545-2344

7 H, D Oscilloscope HP 180D, 1805A, 1825A 6625-00-022-8228
8 H, D Coaxial Cable HP 10507A 6625-00-518-2899
9 H, D Extender Cable HP 105063B CX-11487/U 6625-00-868-6931

(length 1 ft. 7 in.)
10 H, D Feed-through Termination HP 10100A (2 required) 6625-00-880-3947
11 H, D DC Power Supply Kepco HB 525M20480 6130-01-033-3936
12 H, D Tool Kit TK-101/U 5180-00-064-5178
13 H, D Tools and test equipment as authorized to the

repair mission user to complete the assigned

mission.

3AN,

HP 3490A 4931-00-407-26L2

6625-00-557-8305

6625-00-819-0472

D-4

SECTION IV. REMARKS

REFERENCE REMARKS

CODE

A VISUALS.
B REPLACE FUSES, KNOBS, ETC.
C PERFORMANCE TESTS ONLY.

D-5

CHANGE 1:

Model 5261A

APPENDIX E

This manual applies directly, to the .5261A Video Amplifier having serial number prefix 1124A.
This manual with the following changes also applies to 5261A having serial number prefix :301,
311, 510, 960, and 1104.

FOR SERIAL PREFIX PERFORM CHANGE

301, 311 1, 2, 4
510 2, 4
960 3, 4
1104 4

Figure 1 of Appendix E Change A4R16 to a chassis part and designate

R1.

Tables 6 1, 6-2 Change: MP5 Front Panel to HP Part No

05261-2003.

Change: MP9 Meter Mounting Bracket to HP

Part No. 05261-006.
Delete. A4R16
Add: R1 HP Part No. 0760-0012, R fxd, metal

film 51 ohm 2% 1W

CHANGE 2:

A1 05261-6005 ASSY:PREAMPILIFIER BOARD

A1C1 0170-0055 C:FXD MY 0.1UF 20% 200VDCW
A1C2 0160-0127 C:FXD CER 1UF 20% 25VDCW
A1C3 0150-0096 C:FXD CER 0.05UF 100VDCW
A1C4 0150-0096 C:FXD 0.05UF 100VDCW
A1C5 0150-0096 C:FXD CER 0 05UF 100VDCW

A1CR1 1910-0016 SEMICON DEVICE DIODE GERMANIUM
A1CR2 1910-0016 SEMICON DEVICE DIODE GERMANIUM

A1Q1 1854-0019 TRANSISTOR:2N2368
A1R1 0683-8245 R:FXD COMP 820)K OHMS 5% 1/4W

A1R2 0683-1545 R:FXD COMP 150K OHMS 5% 1/4W
A1R3 0757-0344 R:FXD MET FLM 1 MEGOHM 1% 1/4W
A1R4 0683-9105 R:FXD COMP 91 OHMS 5% 1/4W
A1R5 0683-3625 R:FXD COMP 3600 OHMS 5% 1/4W

A1R6 068:3-9115 R:FXD COMP 910 OHMS 5Ar’ 1D4W
A1V1 1921-0015 ELECTRON TUBE: 8056 NUVISTOR TRIODE

Page 6-2, Table 6-1 Delete items A1 through A1R7

Add the following

05261-2002 BLANK PRINTED CIRCUIT BOARD

A1XV1 1200-0086 SOCKET:NUVISTOR 5 PIN

E-1

CHANGE 2:

Continued)

Page 6 4, Table 6-1 Add A4R16 0760-0012 R:FXD MET FLM 51

OHM 2% 1W
Add C2 0150-0005 C:FXD CER 1000 PF’

500VDCW
Add MP6 05261-2001 PLT MTG FOR A1

Page 6-5. Table 6-2 Change Table 6-2 to reflect above part changes.
Page 5-6, Figure 5-2 Replace Figure 5-2 with Figure 1 of Appendix 1
Page 5-7, Figure 5-3 Replace Figure 5-3 with Figure 2 of Appendix 1
Page 5-7, Figure 5-4 Replace Figure 5-4 Video Amplifier Schematic

with Figure 3 of Appendix 1

CHANGE 3

Page 6-2, Table 6-1 Delete A1C 0160-0975 .001UF 20% 75VDCW

Delete A1R7 0683-1045 100K OHM 5% 1/4W

Model 5261A

Appendix E

Page 6-5, Table 6-2 Change Table 6-2 to reflect above part changes
Page 5-7, Figure 5-3 Replace A1 portion of component locator

with Figure 4 of Appendix 1

Page 5-7, Figure 5-4 Replace Figure 5-4 Video Amplifier Schematic

with Figure 5 of Appendix 1

CHANGE 4

Page 6-4, Table 6-1 Delete from MP5 description “OPTION A85

(LIGHT GRAY)”
Delete from “MP5 05261-2011 PANEL: FRONT STANDARD

(MINT GRAY)”

E-2

FIGURE A-1. Top View, Component Location

Model 5261A

Appendix E

E-3

FIGURE A-2. Bottom View, Component Location

Model 5261A

Appendix E

E-4

Model 5261A

Appendix E

FIGURE A-3. Video Amplifier Schematic

E-5

FIGURE A-4. A1 Preamplifier, Component Location

E-6

Model 5261A

Appendix E

FIGURE A-5. Video Amplifier Schematic

Model 5261A

Appendix E

E-7

By Order of the Secretary of the Army:

Official:

J.C. PENNINGTON

Major General, United States Army

The Adjutant General

DISTRIBUTION:

To be distributed in accordance with Special List.

E.C. MEYER

General, United States Army

Chief of Staff

PIN: 046855 000

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