RECEIVER AUDIO RESPONSE TEST (X-MODE).

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

3-8.

RECEIVER AUDIO RESPONSE TEST (NORMAL MODE). (CONT)

STANDARD. ME-30(*)/U should indicate between 14 and 22 volts.

26. If ME-30(*)/U indicates below 14 volts or above 22 volts, see troubleshooting chart 3-5.

3-9.

RECEIVER AUDIO RESPONSE TEST (X-MODE).

PURPOSE. This test is similar to the Audio Response Test (Normal Mode). When set up for X-

mode, however, the R-442/VRC responds to a wider band of frequencies because the A5000 tray is

not used. The ability of the receiver to detect and respond flatly to the desired intelligence is verified

by comparing db readings taken at the MK-1978/VRC, X-MODE AUX RCVR jack while injecting several

modulating frequencies to a reference voltage measurement taken at 1-kHz modulation.

R-442/VRC X-MODE SETUP PROCEDURE

Remove bottom cover from R-442/VRC. (See paragraph 2-7).

Raise A4000 tray and secure brace.

Remove Filter FL4002.

Rotate Filter FL4002 180 degrees.

Put Filter FL4002 back into tray.

Set X-MODE-NORMAL Switch S4001, located underneath tray, to X-MODE position.

Release brace and lower A4000 tray.

Replace R-442/VRC bottom cover.

TEST EQUIPMENT AND MATERIALS

Power Supply PP-1104(*)/G

Adapters (two) UG-274 B/U (T-

Frequency Counter AN/USM-207

Connector) and UG-514

Matching Unit CN-901/U

Signal Generator AN/URM-103

Rf Cables (three) RG-58/U

Signal Generator AN/URM-127

Maintenance Kit MK-1978/VRC

Ac Voltmeter ME-30(*)/U

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

3-25