RECEIVER AUDIO RESPONSE TEST (NORMAL MODE).

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

4-7. RECEIVER AUDIO DISTORTION TEST. (CONT)

STANDARD. MM-100E (distortion) meter should indicate less than 8 percent.

4. If MM-100E meter indicates 8 percent or above, see troubleshooting chart 4-7.

4-8. RECEIVER AUDIO RESPONSE TEST (NORMAL MODE).

PURPOSE. This test checks the R-442/VRC A5000 tray for a flat response to modulating frequencies

at and below 3 kHz. Receiver circuits are said to have a flat response if their gain remains nearly

constant over a specified bandwidth. Frequencies not falling within this limited range receive little or

no gain. The ability of the R-442/VRC to detect and respond flatly to the desired voice frequencies Is

verified by injecting 1 kHz, 500 Hz, and 3 kHz into its ANTENNA port and insuring that the power

measured at the SPKR jack of the MK-1978/VRC falls within the required db range.

TEST EQUIPMENT AND MATERIALS

Power Supply PP-1104(*)/G

Test Set AN/GRM-114A

Maintenance Kit MK-1978/VRC

Rf Cable RG-58/U

TEST EQUIPMENT SETUP. Connect equipment as shown in test setup diagram

4-19