OPERATIONAL CHECK. Continued
Step 3. AUDIO AMPLIFIER CHECK FOR AM-7239/VRC AND AM-7239B/VRC. Continued
n. Set PTT: UUT. Read scope.
o. Set PTT: OFF.
p. Disconnect cable at J2 and move it to J4.
q. Set PTT: UUT. Read scope.
r. Set PTT: OFF.
s. Set LOGIC: 2. Read scope.
t. Remove X10 probe and mini probe tip
adapter from test adapter SCOPE 1.
Remove X10 probe from SCOPE CH A.
Connect cable from test adapter SCOPE 1
to SCOPE CH A. Disconnect cable at J4
and move it to J5.
Set CAL: FCTN GEN:
1800 Hz (1750 to 1850 Hz)
LEVEL: 300 mV p-p
(250 to 350 mV p-p)
Set CAL: MOD GEN:
600 Hz (550 to 650 Hz)
MOD AMPLITUDE: MID-RANGE
MOD FCTN :
MODULATION: FM: INT.
Set CAL: OFF.
Set STIMULUS: 1.
Set TEST EQPT SELECTOR: SCOPE.
Set RESPONSE: 6
Set RESP SEL: S1.
Set STIM SEL:
HANDSET. Read scope.
u. Set PTT: UUT. Read scope.
v. Set PTT: OFF.
w. Set STIM SEL: FCTN GEN.
Set PIT: UUT. Read scope.
x. Set PTT: OFF.
n. Scope reading is less than 0.5 V p-p. If
not, go to chart 15.
o. No response.
p. No response.
q. Same response as for step 3 n. If not, the
wire from 5A3J2-C to 5A3J4-C, or connec-
tor 5A3J4, is bad.
r. No response.
s. Scope reading is less than 0.5 V p-p. If
not, go to chart 16.
t. Scope reading is -0.2 to 0.2 V dc. If not,
the audio amplifier (5A2) is bad.
u. Scope reading is 0.8 to 1.3 V dc when
PTT: UUT, then -0.2 to 0.2 V dc within
1 second. If no signal is present, go to
chart 17. If a signal is present but not
correct, the audio amplifier (5A2) is bad.
v. No response.
w. Scope reading is 0.8 to 1.3 V dc. If signal
is same as in step 3 u, go to chart 18. If
not, the audio amplifier (5A2) is bad.
x. No response.