RECEIVER AUDIO DISTORTION TEST. - TM-11-5820-401-34-30382

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

5-6. RECEIVER AUDIO POWER TEST. (CONT)

NOTE

To produce a display on the AN/USM-207, the AN/URM-103 rf level must be increased

by turning the LO RF UV control clockwise. When the display appears, readjust the

AN/URM-103 RF TUNING control until the AN/USM-207 indicates 60.00 MHz, and reset

the LO RF UV control to 20 v.

4, Disconnect T-connector from AN/USM-207.

5. Turn R-442/VRC VOLUME control fully clockwise.

STANDARD. ME-30(*)U meter should indicate at least 17 volts.

6. If ME-30(*)/U meter indicates less than 17volts, see troubleshooting chart 5-10.

Unmuted Audio Power Test

7. Disconnect 600-ohm resistor lead from Test Cable No. 1 terminal F and connect it to terminal 5.

(See test setup diagram

8. Connect ME-30(*)/U INPUT lead A to Test Cable No. 1 terminal 5; connect lead B to terminal

A. (See test setup diagram

9, Set ME-30(*)/U RANGE selector switch to lower settings until reaching most exact on-scale

reading.

STANDARD. ME-30(*)/U meter should indicate at least 7.75 volts.

10. If ME-30(*)LJ meter indicates less than 7.75 volts, see troubleshooting chart 5-10.

Fixed Audio Power Test

11. Connect ME-30(*)W INPUT lead A to Test Cable No. 1 terminal K; connect lead B to terminal

A. (See test setup diagram

12. Set ME-30(*)/U RANGE selector switch to lower settings until reaching most exact on-scale

reading.

STANDARD. ME-30(*)/U meter should indicate at least 0.16 volt.

13. If ME-30(*)/U meter indicates less than 0.16 volt, see troubleshooting chart 5-10.

5.7. RECEIVER AUDIO DISTORTION TEST.

PURPOSE. This test checks the ability of the R-442/VRC to minimize distortion. It is similar to the

Receiver Sensitivity Test (paragraph 5-3), except that now a strong (20-v) rf level is used instead of

a weak (0.5-v) one. The 20-v level is injected into the R-442/VRC ANTENNA port. The audio

distortion, measured at the MUTED AUDIO output terminal (pin F) of Test Cable No. 1, should be less

than 8 percent.

5-18