CHP Mobile Repeating - Switchable?

[bigmattyl]

Hey guys,

I was noticing down here in Southern CA...

The Santa Ana Purple channel.. wasnt repeating mobiles for a span of about 2 days. then seemed to switch back to normal repeated operation.

Out of curiosity, does this happen often, and what is the reason for the switch and then the switch back

Matt

 

[gmclam]

CHP repeat

I haven't listened to that specific channel in some time, but certainly the 'repeat' function can be turned on and off by the whim of the dispatcher. CHP has a unique system where a mobile can be received by several different mountain top repeaters. The one with the 'best' signal is selected and routed to the dispatcher. That signal can then be selectively sent back out over the dispatch channel (on the same mountain top).

This is one of the many reasons that I always monitor mobile frequencies too.

 

[bigmattyl]

On that note, it also seems like the units can talk to each other on the base frequency without the dispatcher hearing it.

 

[pepsima1]

Does anybody have a list of CHP 10 codes and or all of the codes they use over the radio? Not sure if this is public info or not. Maybe its somewhere I can find it on the internet.

 

[pepsima1]

Sorry I found it.

Thanks

California Highway Patrol Codes & Abbreviations

 

[bigmattyl]

if you want it right from the horses mouth.. ou can go to

cad.chp.ca.gov..

and then on the resources drop down on the top right menu.. choose glossary

Matt

 

[pepsima1]

The horses mouth is a nice resource too.

thanks

 

[ko6jw_2]

CHP repeaters

The previous post regarding the dispatcher's ability to switch the repeater function on and off is correct. However, there is another issue. The mountain top sites are not linked together. Therefore, a repeat function enabled on one site will not be repeated on all sites. This is not a problem in metropolitan areas like Santa Ana, but where I am in the Coastal Division it is a problem. A few years ago the Santa Ynez Peak site was being operated in the repeater mode by the San Luis Obispo dispatch center. You could hear cars all over the Division, but you could not hear the dispatchers if they were using a distant site. Not very good. They stopped doing this quite a while back.

There are problems with operating linked repeaters as all transmitters must be synchronized to avoid phase distortion. Not easy to do. The Santa Barbara County Fire Department tries to do this. It requires almost daily re-calibration and even then it's problematical. I can hear several linked repeaters at my location and phase distortion is always present to some degree. This is on 153-155Mhz. It would be worse for the CHP on 39-42 Mhz.

 

[bigmattyl]

Also, it seems like the units can communicate with each other on the base frequency with out the dispatcher hearing it.

 

[KJ6ZNS]

The units can go car to dispatcher, or car to car, depending on which way they rock the mic ptt button. Car to car has both units on simplex on the receive frequency.