RECEIVER AUDIO POWER TEST. - TM-11-5820-401-34-30102

TM 11-5820-401-34-3/0967-LP-432-3060

3-5. OLD SQUELCH TEST. (CONT)

27. Adjust AN/URM-103 RF TUNING control for 75.00-MHz display on AN/USM-207. To produce

display, see note under step 1 and readjust RF TUNING control until AN/USM-207 indicates

75.00 MHz.

28. Repeat steps 2 through 8.

3-6. RECEIVER AUDIO POWER TEST.

PURPOSE. This test checks the ability of the R-442/VRC to drive its three audio outputs, namely:

1. The MUTED audio output, which supplies power to the speaker.

2. The UNMUTED audio output, which supplies power to the headphones.

3. The FIXED LEVEL audio output, which supplies power to the interphone system.

An rf level strong enough to drive the A4200 module into limiting (20v) is injected into the R-442/VRC

ANTENNA port. The audio output voltages are then measured at the SPKR and INTERCOM jacks of the

MK-1978/VRC.

TEST EQUIPMENT AND MATERIALS

Adapter (T-Connector) UG-274 B/U

Power Supply PP-1104(*)/G

Matching Unit CN-901/U

Ac Voltmeter ME-30(*)/U

Maintenance Kit MK-1978/VRC

Frequency Counter AN/USM-207

Rf Cable RG-58/AJ

Signal Generator AN/URM-103

TEST SETUP. Connect equipment as shown in test setup diagram

3-16