NEW SQUELCH TEST. - TM-11-5820-401-34-30094

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

3-3. RECEIVER SENSITIVITY TEST. (CONT)

Sensitivity Test at 52.00 MHz

28. Change R-442/VRC MC-TUNE-KC switch to 52.00 MHz and BAND to

29. Turn AN/URM-103 BAND SWITCH to

and RF TUNING control for 52.00-MHz meter

indication.

30. Reconnect TS-723(*)/U METER lead C to MK-1978/VRC SPKR jack; reconnect lead D to GND

jack.

31. Adjust AN/URM-103 RF TUNING control for 52.00-MHz display on AN/USM-207. To produce

display, see note under step 2 and readjust RF TUNING control until AN/USM-207 indicates

52.00 MHz.

32. Repeat steps 3 through 12,

Sensitivity Test at 75.00 MHz

33. Change R-442/VRC MC-TUNE-KC switch to 75.00 MHz and BAND to

34. Turn AN/URM-103 BAND SWITCH to

and RF TUNING control for 75.00-MHz meter

indication.

35. Reconnect TS-723(*)/U METER lead C to MK-1978/VRC SPKR jack; reconnect lead D to GND

jack.

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

display, see note under step 2 and readjust RF TUNING control until AN/USM-207 indicates

75.00 MHz.

37. Repeat steps 3 through 12.

NEW SQUELCH TEST.

3-4.

PURPOSE. This test checks the sensitivity of R-442/VRC squelch modules (A5200, A5300) to the

NEW SQUELCH signal (150 Hz) at several carrier frequencies. The 150-Hz signal is injected into the

R-442/VRC ANTENNA port, energizing Squelch Module Relay K5002, which unsquelches the

receiver. Proper operation of the squelch modules is verified by CALL lamp response to carrier signal

strength at or below a 0.5- rf level.

TEST EQUIPMENT AND MATERIALS

Matching Unit CN-901/U

Power Supply PP-1104(*)/G

Rf Cables (two) RG-58/U

Frequency Counter AN/USM-207

Maintenance Kit MK-1978/VRC

Signal Generator AN/URM-103

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

3-8