Specifications

TM 11-5820-670-30
2-10. RECEIVER TONE SQUELCH SENSITIVITY TEST.
(CONT)
EQUIPMENT
TS-2575/ARC-131
TS-723A/U
AN/URM-103
TEST PROCEDURE
CONTROL AND SWITCH SETTINGS
CONTROL OR SWITCH
MODE SWITCH
VOL
SQUELCH
FREQ set
FUNCTION switch
RANGE
AF-RF switch
BAND SWITCH and RF TUNING CONTROL
FUNCTION switch
RF OUTPUT switch
LO-HI RF SET to LINE CONTROL
and LO RF UV
DEVIATION RANGE KHZ switch
DEVIATION CONTROL
POSITION/SETTING
T/R
Maximum (clockwise)
CARR
30.00 MHz
DISTORTION
X 10
AF
Adjust to 30.00 MHz.
EXT MOD
LO 0-10 KUV
Adjust as required in
procedures.
10
Midrange position
1. Adjust AN/URM-103 for 30.00 MHz as indicated by minimum distortion on TS-723A/U.
2. Set the SQUELCH switch on TS-2575/ARC-131 to TONE.
3. Adjust AN/URM-127 (no. 2) output frequency to 150 Hz as indicated on AN/USM-207 readout.
4. Adjust output level of AN/URM-127 (no. 2) to produce 1 kHz deviation as indicated on
AN/URM-103 meter.
5. Adjust AN/URM-127 (no. 1) output frequency to 1000 Hz.
6. Adjust output level of AN/URM-127 (no. 2) to produce 8 kHz deviation as indicated on
AN/URM-103 meter.
7. Reduce AN/URM-103 output to minimum. Monitor audio output on the TS-723A/U meter.
8. Increase AN/URM-103 output until an audio output indication is observed.
STANDARD. Audio is present.
9. If audio is not present, see troubleshooting chart 2-12.
10. Observe AN/URM-103 output level (squelch pull-in).
STANDARD. 0.5 microvolt maximum
11. If AN/URM-103 output level is more than 0.5 microvolt, see troubleshooting chart 2-12.
2-21