Initial Settings and Adjustments. - TM-11-5820-509-350218

TM 11-5820-509-35

(2) Remove the dust cover from the module,

(6) Set the audio oscillator output frequency

to 1700 Hz and adjust the level at AUDIO IN jack (J8) to

and plug it into the test fixture.

1.25 volts rms. If the voltmeter reads 0.5 0.1 volt rms

(3) Apply primary power to all test

at XMIT OUT jack (J8) continue to step (9) If not,

instruments and turn on each of the units. Immediately

perform steps (7) and (8)

adjust the output of the 24 volts power supply to 20.0

(7) Connect the resistance decade box at the

1.0 volts, the output of the 7 volts power supply to 6.0

eyelets normally used to attach R14 (fig. 3-20), after

0.5 volts, and the output of the 110 volts power supply

removing R14. Set the selector knobs on the decade

to -110 3.5 volts dc.

box to 3900 OHMS.

(4) Place the POWER switch on the test

(8) Repeat step (6) and adjust the resistance

fixture to ON, the AGC and ALC BIAS switches to OFF,

settings of the-resistance decade box until the voltmeter

the XMIT-RCVR switch to RCVR and the METER

reading specifies) is obtained.

Select a suitable

RANGE switch to 200. Permit the test equipment and

resistance and install it in the module at the eyelets from

the module to stabilize for at least 5 minutes before

which the original R14 was removed.

beginning the following procedures.

NOTE

NOTE:

Repeat step (6) after installation of the

Perform the initial adjustments and

replacement R14 to verify that proper

each of the following tests in the

output is indeed available at XMIT OUT

order listed to avoid erroneous test

jack (J4).

results or maladjustment of the

(9) Adjust capacitor C35 and potentiometer

module alignment.

R5 on the module to minimize the carrier indication on

e. Initial Settings and Adjustments.

the spectrum analyzer.

(1) Set the signal generator to 498.3 kHz (cw

NOTE

operation) and adjust the output level to 100 microvolts

If capacitor C35 is adjusted to either

at RCVR IN jack (J6) Connect the voltmeter to AUDIO

limit, select a new value for shunting

OUT jack (J7} and adjust Cl5, C17, L6, L7, and T3 for

capacitor C36 that permits an

maximum output. Record this output reading in dB for

intermediate setting. Repeat step (9), if

reference below.

necessary.

(2) Slowly vary the signal generator output

d. Output, Receive.

frequency between 497.0 and 499.7 kHz and observe

(1) Place the XMIT-RCVR switch on the test

the point at which minimum output occurs.

The

fixture to RCVR (the AGC and ALC BIAS switches

minimum audio output level at J7 shall not be more than

remain OFF).

3 dB below the reading recorded in step (1) above.

(2) Disconnect the audio oscillator and the

NOTE

spectrum analyzer converter from the test fixture and

If the minimum audio output level is

connect the voltmeter to AUDIO OUT jack (J7)

greater than 3 dB below the

(3) Connect the signal generator and

maximum output level observed in

frequency counter to RCVR IN jack (J6) and set the

step (1), set the signal generator to

signal generator output frequency to 498.3 kHz.

this frequency. Then readjust C15

(4) Adjust the output level of the signal

and C17 to increase the output until

generator until the voltmeter reads 0.1 volt rms; then

it meets the performance standard.

move the voltmeter to RCVR IN jack (J6) and measure

Repeat steps (1 ) and (2) to verify.

the output level of the signal generator. The level at J6

(3) Place the XMIT-RCVR switch on the test

shall not be greater than 200 microvolts.

fixture to XMIT (the AGC and the ALC BIAS switches

e. Distortion, Receive.

remain OFF); connect the voltmeter and spectrum

(1) The AGC and ALC BIAS switches remain

analyzer converter to the XM IT OUT jack.

OFF and the XMIT-RCVR switch remains in the RCVR

(4) Connect the audio oscillator to AUDIO IN

position.

jack (J8) Set the output frequency to 2800 Hz and adjust

(2) Verify that the signal generator output

the output level to 1.25 volts rms.

frequency is 498.3 kHz and that the output is connected

(5) Adjust transformer T2 (fig.

3-7) and

to RCVR IN jack (J6).

inductor L4 to obtain a maximum indication on the

voltmeter at XMIT OUT jack (J4).

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