Motorola VRS750, Service Manual

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Do this until the radio is totally unmuted. Verify the squelch
closing by inputting a signal level of 4 dB lower (than that of the
-110 dBm level).
4. Repeat steps 1-3 for F2-F7.
5. Press Program to commit the softpot values into the codeplug.
6. Exit the Squelch Attn. function. The mobile will reset upon
exiting.
NOTE: The Auto Tuning feature does not work for the
VRS750.
Table 4 shows the softpot ranges to achieve approximately -110 dBm.
The actual value varies from radio to radio. The VRS transceiver ships
from the factory with the softpot set for -110 dBm. In the event that
this value needs to be re-set in the field, it is recommended that a
communications analyzer or similar piece of test equipment be used to
verify these settings.
Other adjustments can be made using the Global Tuner in the event
that the transceiver is replaced. For more information, refer to
“Transceiver Board Tuning Procedure,” in Chapter 7.
When all adjustments have been made, select File --> Program All .
This will program all off the softpot values into the VRS750’s EEPROM.
VRS750 Upgrade Kit
The VRS750 firmware can be reprogrammed/reflashed using the
VRS750 Upgrade Kit. In order to use the VRS750 Upgrade Kit the
VRS750 should be connected to a desktop or laptop PC via a COM port
as indicated in Figure 13. The Flash adapter (NTN4056A) should be
placed between the VRS750 programming cable (3085031D02) and
the SRIB (see Figure 16). When connecting the VRS750 to the SRIB via
the Flash adapter,
make sure that the switch on the adapter is in the
“B” position . With the ASTRO mobile powered on and “PROG VRS”
displayed on the control head, the upgrade can be started. Open the
VRS750 Upgrade Kit and click on the “PROGRAM” button. Follow the
instructions through to the completion of the Flash process. Upon
completion, place the switch on the Flash adapter back in the “B”
position and disconnect the VRS750 from the programming cable. For
more detailed information on the flashing process, consult the “read
me” file for the Upgrade Kit.
Table 4. Softpot Ranges
Band
Channel
Spacing (kHz)
Approximate Softpot
Range for -110 dBm
VHF 25 56-63
VHF 12.5 63
UHF R1 25 44-52
UHF R1 12.5 63
UHF R2 25 43-46
UHF R2 12.5 63