Motorola VRS750 Service Manual page 70

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b. Set the Mobile Communications Analyzer frequency to the
current mobile mode.
c. Switch on the Mobile Communications Analyzer RF.
d. Adjust R150 on the VRS board until 3.0 kHz deviation is
obtained on the VRS Communications Analyzer.
e. Switch off the Mobile Communications Analyzer RF.
3. Adjust the Mobile Microphone Deviation Level:
a. Inject a 1 kHz tone at 80 mVrms into the mobile microphone.
b. Key the mobile microphone. (Refer to the ASTRO Spectra
Mobile service manual for specialized equipment.)
c. Adjust the signal level of the 1 kHz tone until 3.0 kHz
deviation is obtained on the Mobile Communications
Analyzer.
d. Adjust R148 on the VRS board until 3.0 kHz deviation is
obtained on the VRS Communications Analyzer.
e. Dekey the mobile microphone.
4. Adjust the Mobile Deviation Level:
NOTE: Set the VRS Communications Analyzer RF output to
-50 dBm with a standard test modulation (1 kHz tone,
3 kHz deviation) and any receive PL for which the VRS
is programmed (750 Hz deviation). If the receive PL for
"select mode" is not used, the Mobile
Communications Analyzer frequency may need to be
adjusted.
a. Set the Mobile Communications Analyzer frequency to the
current mobile mode.
b. Switch on the VRS Communications Analyzer RF.
c. Adjust R146 on the VRS board until 3.00 kHz deviation is
obtained on the Mobile Communications Analyzer.
d. Switch off the VRS Communications Analyzer RF.
5. Check the VRS RF Sensitivity:
a. Set the VRS Communications Analyzer RF output to -115 dBm
with a standard test modulation (1 kHz tone, 3 kHz deviation)
and any receive PL for which the VRS is programmed (750 Hz
deviation).
NOTE: If the receive PL for "select mode" is not used, the
Mobile Communications Analyzer frequency may
need to be adjusted.
b. Switch on the VRS Communications Analyzer RF. The unit
should not retransmit this signal to the Mobile
Communications Analyzer.
c. Slowly increase the input signal. The unit should begin
repeating to the Mobile Communications Analyzer at no
more than -104 dBm.