Service manual

Page 7
SVR-250 Service Manual
Wide Band / Narrow Band Channels
The SVR-250 can be programmed for Wide/Narrow band operation on a per channel basis. Wide band
operation is 25kHz for UHF and 800 MHz, 30kHz for VHF. Narrow band is 12.5kHz for UHF and 800 MHz,
15kHz for VHF. VHF channels can be in 5 or 6.25kHz steps on a per channel basis. UHF is programmed in
12.5kHz steps. 700/800/900 MHz are programmed in 6.25kHz steps. 700 and 900 MHz are only available as
narrow band (12.5 kHz). In addition to changing the receiver bandwidth and transmitter modulation characteristics,
the audio levels into and out of the SVR-250 are automatically adjusted so the levels at the mobile will be correct
with either bandwidth selected.
Courtesy Beep
If enabled, the SVR-250 will send a short beep to the handheld user at the end of each portable-to-base
transmission to confirm that the user is still within range.
Power Up Channel
The SVR-250 can be programmed to revert to the last channel used when powered down or a pre-programmed
"Home" Channel.
Full Duplex Operation
The SVR-250 can be configured to operate full duplex and repeat portable-to-portable during portable-to-base
transmissions, thereby extending coverage between portables as well as operating as a vehicular repeater. Full
duplex operation requires hardware and firmware changes and is not field upgradeable. Full duplex operation
is not compatible with multi-vehicle format and should only have 1 SVR-250 on scene. The SVR-250 configured
for duplex operation will have separate Tx and Rx antenna connectors and requires an external duplexer or
separate Tx and Rx antennas.
LEDs
The SVR-250 has a 2 digit channel display as well as eight status LEDs:
CPU: Flashes at a 1 Hz rate to indicate proper operation of the microprocessor.
PRI: When on, indicates that the unit is at priority count zero and will repeat all transmissions.
RCOR: Repeater Carrier detect.
RTONE: Repeater sub-audible decode; when on, indicates a condition to repeat portable-to-base.
RTX: Repeater transmit indicator.
MCOR: Mobile unmute detector indicating a condition to repeat base-to-portable.
MTX: Mobile transmit indicator.
OPT: Continuous illumination indicates Emergency/Dual Tone PL Decode. If OPT LED flashes at 10Hz
rate, it is an indication that one of the PLLs did not lock within the allotted 50mS and the unit should
be serviced.