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LBI-38953
•
Pin Extractor Tool (11-03-0038) - Al-
ST3712
lows removal of contacts from con-
nector shell that mates with option
cable CC01. The option cable is re-
quired with all external options
•
Alignment Tool - with two ceramic
ST2513
tips - used for squelch control and
other adjustments
•
Crimping Tool - for field attachment
ST2617
of TNC - series male connectors
19A115903P1 to RG-58/U (and simi-
lar) coaxial cable
TRANSMITTER ALIGNMENT
Frequency Set
In the test mode, key the transmitter (FCN 0 1) and
measure the transmit frequency. The frequency should be
within ±250 Hz of the test mode channel frequency. If not,
adjust U204 to within ±100 Hz. (Push END to turn off the
transmitter.)
The temperature should be 25 ±5°C. Ensure fre-
quency counter calibration is better than ±0.1 PPM.
Normal Mode Modulation Set
1. Apply a 1 kHz, 2 Vrms signal to the TX AUDIO input
of the test box (TQ0618).
2. Select channel 649 (CLR 649 CLR) at 814.000 MHz.
Turn on the TX audio (FCN 0 4). Turn on the Tone
Channel Guard (FCN 25) which also keys the transmit-
ter. Adjust modulation pot R254 for 4.2 +0.1, -0.2 kHz
deviation.
Direct Mode Modulation Set
1. Apply a 1 kHz, 2 Vrms signal to the TX AUDIO input
of the test box (TQ0618).
2. Set the Bandswitch line low (FCN 2 1).
16
NOTE
3. Select a talk-around channel 4249 (CLR 4249 CLR) at
859.000 MHz. Turn on the TX audio (FCN 0 4). Turn
on the Tone Channel Guard (FCN 2 5) which also keys
the transmitter. Adjust the modulation pot R226 for 4.2
+0.1, -0.2 kHz deviation.
Pressing RCL resets the radio to the first frequency
in the frequency set and also sets the bandswitch
line high.
Transmitter Power Set
1. While on channel 649, key the transmitter (FCN 0 1),
and adjust R111 in the power control circuit for 11 watts.
2. Push END to unkey the transmitter.
RECEIVER ALIGNMENT
Frequency Set
1. Verify that the transmitter is on frequency as described
in the transmitter alighment above.
2. Inject a strong, unmodulated on-channel signal (-60
dBm) at the antenna input, J101.
3. Monitor J501 with a frequency counter and adjust L508
for a reading of 455 kHz ±100 Hz.
IF Tuning
1. Monitor J501 with an AC voltmeter and inject an on-
channel signal at the antenna jack modulated with a 60
Hz ramp at 5 kHz deviation.
A 1 kHz tone may be used if a 60 Hz rmap is not
available.
2. Adjust L504, L506, and L507 as indicated on the AC
voltmeter. Adjust the level of the signal generator to
keep the signal at J501 out of limiting (approximately
-65dBm).
3. Repeak the coils.
NOTE
NOTE
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