Service manual

ALIGNMENT AND TEST PROCEDURES
7-15
Month 2000
Part No. 001-2004-601
Repeat Audio Level Adjustment
NOTE: Audio Deviation Limit Adjustment must be
completed before this test.
1. Adjust the RF generator for 100 µV into the
receiver with a 1 kHz tone at ±1.5 kHz deviation
(25 kHz channels) or ±800 Hz (12.5 kHz channels).
Be sure the Modulation Analyzer LPF switch is set
to 3 kHz.
2. Use the "Turn on carrier" button to key the transmit-
ter.
3. On the MAC, adjust R237 to achieve ±1.5 kHz
(±100 Hz) transmit deviation (25 kHz channels) or
±800 Hz (12.5 kHz channels). Be sure the modula
-
tion analyzer LPF switch is set to 3 kHz.
4. Use the "Turn on carrier" button to unkey the
transmitter.
5. Connect an AC voltmeter to J103 and P100, pin 31
(RX_VOICE).
6. Adjust R238 for -3 dBm (548 mV RMS).
7. Remove the RF generator from the Receiver.
Data Level Adjustment
1. Remove VNC cards if present.
Set modulation analyzer LPF to 3 kHz.
Use the "Turn on carrier" button to key the
transmitter.
2. Adjust U151 with the Level Control buttons to
achieve ±1 kHz (±100 Hz) transmit deviation
(25 kHz channels) or ±800 Hz (12.5 kHz channels).
3. Use the "Turn on carrier" button to unkey the trans-
mitter.
Audio/Data Deviation Check
1. On the MAC, apply a 1 kHz tone at +7 dBm (1.73V
RMS) to P100, pin 32. Set modulation analyzer
LPF to 3 kHz.
2. Use the "Turn on carrier" button to key the transmit-
ter.
3. Measured deviation should be ±4.5 kHz (±200 Hz)
(25 kHz channels) or ±2.4 kHz (±100 Hz) (12.5 kHz
channels).
4. Use the "Turn on carrier" button to unkey the
transmitter.
Disconnect all cables.
CWID Level Check
1. Set modulation analyzer LPF switch to 3 kHz.
Use the "Turn on carrier" button to key the
transmitter.
2. Deviation should be 1.5 kHz to 2.5 kHz (25 kHz
channels) or ±0.750 kHz to 1.75 kHz (12.5 kHz
channels).
3. Use the "Turn on carrier" button to unkey the
transmitter.
Local Speaker/Microphone Check
1. On the MAC, plug a Speaker/Microphone into
J101/J102. Set modulation analyzer LPF switch to
3 kHz.
2. Use the "Turn on carrier" button to key the
transmitter.
3. Press the microphone PTT and say "four" loudly
into the microphone.
4. Deviation should measure ±3 to ±3.5 kHz (25 kHz
channels) or ±0.75 kHz to 1.6 kHz (12.5 kHz
channels).
5. Release the microphone PTT.
6. Use the "Turn on carrier" button to unkey the trans-
mitter.