TM 11-5820-890-30-4
12-23. OPERATIONAL CHECK. Continued
Step 8. TRANSMIT ANALOG DATA TEST. Continued
Action
Response
b. Set test adapter:
b. 1.5 to 2.5 V p-p distorted sine wave is
PTT: UUT.
displayed on CH 1 at same frequency as
Observe scope CH 1 for 1.5 to 2.5 V p-p
CH 2. If not, go to chart 32.
distorted sine wave display.
c. While observing scope CH 1 for 1.5 to
c. 1.5 to 2.5 V p-p distorted sine wave is
2.5 V p-p distorted sine wave display,
displayed briefly on CH 1 at half frequency
set test adapter:
of CH 2. If not, the ICOM control module
STIM SEL: HANDSET.
(19A8) is bad.
d. Set test adapter:
d. No response.
PTT: OFF.
Step 9. TRANSMIT DIGITAL DATA TEST.
SET:
REF RT AND RCU:
TEST ADAPTER:
DATA: 4800
CAL:
FCTN GEN (scope trig. CH 2)
BASEBAND: 1
(see Response a.)
FREQ:
2400 Hz (2390 to 2410 Hz)
STIMULUS: 2
LEVEL:
10 v p-p (9.5 to 10.5 v p-p)
STIM SEL: FCTN GEN
FCTN:
SQUARE
TRIGGER:
EXT TRIG
TRIG LEVEL: MID-RANGE
CAL:
OFF
Action
Response
a. Set test adapter:
a. 9.5 to 10.5 V p-p square wave is
PTT: UUT.
displayed on CH 1. If not, go to chart 33.
Observe scope CH 1 for 9.5 to 10.5 V p-p
If data rate could not be scrolled to 4800,
square wave display.
the control module (19A2) is bad.
b. Move fine frequency adjust on function
b. Adjustment is successful. If not, the ICOM
generator until scope CH 1 is locked-up.
control module (19A8) is bad.
c. Set test adapter:
c. No response.
PTT: OFF.
12-37
