Service manual

8000 SERIES RECEIVER DECODER MODULE (RDM)
2-4
March 2000
Part No. 001-3139-502
2. Connect a SINAD meter to the AUDIO TEST jack
on the receiver drawer front panel.
3. Increase the generator output to obtain a SINAD
reading of -12 dB. The generator output should be
0.35 microvolt or less.
4. If using diversity antennas, connect the generator to
the other antenna jack and sensitivity should be the
same.
2.7.2 DIVERSITY AND SQUELCH THRESHOLD
LEVEL
1. Connect the generator to the receive antenna jack as
described in the preceding section. Connect an AC
voltmeter to the AUDIO TEST jack.
2. With no RF generator output signal, note the read-
ing on the AC voltmeter. This is the 0 dB reference.
Adjust the LOCAL AUDIO control so that audio
can be heard from the speaker when the audio
unsquelches.
3. Switch diversity control switch S1 on the receiver
board to the center "DIV" position. Increase the
unmodulated generator output so that the audio
unsquelches.
4. Decrease the generator output and the audio should
unsquelch when the meter reading is 6-7 dB below
the 0 dB reference. If not, refer to Service Manual
(see Section 2.1).
2.7.3 RECEIVE DATA LEVEL
1. Connect an RF signal generator to the appropriate
receive antenna jack. Set the generator for the
receive channel frequency with an output level of
100 microvolts, modulated with 100 Hz at ± 1 kHz
deviation.
2. The data signal at TP8 on the logic board should be
0.56 volt P-P or 0.34 volt RMS. If not, refer to
Service Manual (see Section 2.1).
Figure 2-3 800 MHz RECEIVER ALIGNMENT POINTS DIAGRAM