Teat Fixture for Amplifier-Modulator AM- 3507/PRC-47

TM 11-5820-509-35

Symbol

Description

Mfgr Part No.

Mfgr Code

VR1

Semiconductor device, diode, 20 V 5%

1N2984B

XDS1, XDS2

Light (FSN 6210-825-2051)

101-3830-9

72619

Lens, p/o XDS1 (FSN 6210-511-8208)

101-972

72619

Lens p/o XDS2 (FSN 6210-174-4680)

101-974

72619

XF1

Fuseholder (FSN 5920-284-7144)

HKPH

71400

Note. All manufacturer's codes are 5-digit numbers. The corresponding

manufacturer's name and address are

listed in SB 708-42 Catalog Handbook (H4-2).

6-18.

Teat Fixture for Amplifier-Modulator AM-

(8) XMIT RCVR switch. This toggle switch

3507/PRC-47

selects the transmit mode, or the receive mode of

operation for the module under test.

(fig. 7-16)

a. The teat fixture for Amplifier-Modulator AM-

(9) AGC ON-OFF switch. This toggle switch,

3507/PRC-47 contains all switches, jacks, tamps, and

when placed in the ON position, applies positive agc

meter necessary to electrically test and adjust the

bias to the module under test.

module without providing a complete AN/PRC-47 Radio

(10) AGC

ADJUST

control.

This

Set. Power for the test fixture and the module under

potentiometer varies the magnitude of bias applied to

test is provided externally and is connected to the test

the agc bias input to the module being tested.

fixture by a specially fabricated cable attached to power

(11) Test jacks and coaxial connectors are

connector J3 at the rear of the teat fixture.

provided for the attachment of signal leads and test

b. The operating controls on the front panel of the

equipment and are self-explanatory.

test fixture (fig. 6-5) perform the following functions:

c. The piece parts required for fabrication of the

(1) POWER ON-OFF switch. This toggle

test fixture are listed in the following chart and

switch controls the +20 volts dc the +6 volts dc and the -

suggested parts placement is shown in figures 6-19 and

110 volts dc input voltages to the test fixture and the

6-20. Schematic diagram (fig. 716) illustrates the

module.

internal circuit of the test fixture.

(2) POWER lamp. This indicator is lit when

d. The following calibration procedure is required

power is connected to the +20 volts dc input of the teat

prior to initial use of the test fixture, and should be

fixture and the POWER ON-OFF switch is in the ON

verified from time to time prior to its use.

position.

(1) Remove the dust cover from the test

(3) POWER 1/2 AMP 28 VDC fuse. This

fixture and connect the 20 volts dc power supply to the

protective device is connected in the +20 volts dc

power cable.

primary power circuit to protect it from overload.

(2) Apply primary power to the 20 volts dc

(4) ALC BIAS ON-OFF switch. This switch

power supply and adjust the power supply output

controls the +6 volt dc alc bias applied to the module

voltage to 20.0 0.5 volts.

under test.

(3) Connect the frequency counter and

(5) ALC BIAS ADJUST control.

This

multimeter rf probe to connector J2 at pin A2.

potentiometer varies the magnitude of effective bias on

(4) Place the POWER ON-OFF switch on the

the -alc line to the module being tested

test fixture to ON and permit the test fixture to stabilize

(6) MICROAMPERES meter. This 0 - 50

for at least five minutes. Place the XMIT-RCVR switch

microammeter indicates the amount of alc bias current

to XMIT.

flowing in the module.

(5) Adjust capacitor C6 (fig. 6-20 and fig. 7.

(7) METER RANGE 50 - 200 switch. This

16) until the frequency counter indicates 500,000.00

switch, when placed in the 200 position, connects a

1.0 Hz; then adjust potentiometer R4 (fig. 6-20 and fig.

shunt across MICROAMPERES meter to extend its

7-16) for a multimeter reading of +1.5 volts rms.

range to 200 microamperes.

6-41