California Highway Patrol (CHP)

When a CHP officer intends to get out of the patrol vehicle, the officer activates the mobile extender unit to transmit and receive radio traffic over the car radio (higher power) via the officer's handheld portable radio.

The mobile extender unit operates on 154.905 MHz (except in Plumas County), and normally listens for transmissions on that frequency from a nearby handheld portable which is then re-transmitted through the car radio mobile out on the car-to-station channel (42 MHz). When the car radio is receiving traffic (on 42 MHz), that traffic is re-broadcast through the extender unit (when enabled) on 154.905 MHz.

The handheld radios are programmed with other frequencies that do not make use of the mobile extender in the patrol car, allowing CHP officer to talk to other CHP portables and other non-CHP radio systems. Channels 7-16 are normally programmed locally to communicate with other public safety systems on the same VHF band within the local geographic area as the CHP area office of the radio being used.

HINT: If you are monitoring 154.905 MHz on a CA highway and you hear radio traffic on the extender, there is a good chance you are within 2 to 3 miles of a CHP unit. This is the same technology used in Uniden's Beartracker radios.

 For Reference Only!  For individual office VRS usage, refer to the Divisional listings.

Outside agency access, special operations, and homeland security use.

Will be located at CHP stations for officers to reach dispatch via their portables. 

Users have recently reported these frequencies being heard as either VRS (Extender) or Talk-Around (Portable-to-Portable) frequencies for CHP officers on details, such as construction zone standby's.