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2. Press the space bar to key the transmitter.
3. Adjust U151 with the PgUp/PgDn and CurUp/
CurDn keys to achieve ±750 Hz ±50 Hz transmit
deviation.
4. Press the space bar to unkey the transmitter.
Audio/Data Deviation Check
1. Remove VNC cards if present.
2. Apply a 1 kHz tone at +7 dBm (1.73V RMS) to
P100, pin 32 of the MAC. (Set modulation analyzer
LPF to 3 kHz.)
3. Press the space bar to key the transmitter.
4. Check for measured deviation out of the modulation
analyzer to be ±2.4 kHz +100/-200 Hz.
5. Press the space bar to unkey the transmitter.
6. Disconnect all cables.
CWID Level Check
1. Set modulation analyzer LPF switch to 3 kHz.
Press the space bar to key the transmitter.
2. Deviation should measure between 750 Hz and
1250 Hz.
3. Press the space bar to unkey the transmitter.
Local Speaker/Microphone Check
1. Plug a Speaker/Microphone into J101/J102 of the
MAC. Set modulation analyzer LPF switch to
3 kHz.
2. Press the microphone PTT and say "four" loudly
into the microphone.
3. Deviation should measure ±1.4-1.6 kHz.
4. Release the microphone PTT.
Transmitter Hum and Noise Ratio (Optional)
ALIGNMENT AND TEST PROCEDURES
NOTE: An HP8901A modulation analyzer is required
for this test.
1. On the modulation analyzer press:
300 Hz HPF
3000 Hz LPF
FM
Pre-Display
750 µS
Avg RMS Cal
0.22
dB
2. Press the space bar to key the transmitter and mea-
sure the Hum and Noise Ratio. The reading shall be
< -45 dB.
3. Press the space bar to unkey the transmitter.
Transmit Audio Distortion
1. Remove VNC cards if present. On the modulation
analyzer select:
FM
50 Hz
15 kHz
2. Apply 200 mV RMS at 1 kHz to P100, pin 32 of the
MAC.
3. Press the space bar to key the transmitter.
4. Adjust audio level to produce ±1 kHz deviation.
5. On the modulation analyzer select:
300 Hz
3 kHz
750 µs de-emphasis
6. Distortion should be < 2%.
7.6.7 TRANSMITTER COMPRESSOR MEA-
SUREMENT
NOTE: This test is valid only with compandor option
installed.
1. Set the modulation analyzer LPF switch to
3 kHz.
2. Apply +7 dBm (1.73V RMS) at 1 kHz to P100, pin
32 on the MAC.
7-17
October 1999
Part No. 001-2009-201
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