Monitoring 42.44 and can only receive the dispatcher. Can’t hear anything on 42.28. Using a low band commercial mobile antenna. Even tried CSQ. Can’t hear mobiles from AZ state line through Palm Springs. Anyone know if that stretch has repeater coverage?
Indio CHP
- Thread starter AZDon
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I used to travel I-10 from Palm Springs to Parker Dam and up to Havasu City. I had a low-band commercial receiver with a noise blanker and base loaded A/S low-band antenna. My maximum range on flat terrain for CHP mobile reception was about 10 miles, but often less. Because of the higher terrain, traveling westbound from about Cactus City I could receive units all the way out to Banning Pass.
In the Blythe area CHP had a strange repeater system that repeated mobile traffic on the west end of Indio's area - the base was not repeated. I presume that has been discontinued because you would have easily heard that traffic.
Your setup is probably doing the best as can be expected for a radio having no noise blanker, unless you are using a commercial radio, which would extend your reception range.
In the Blythe area CHP had a strange repeater system that repeated mobile traffic on the west end of Indio's area - the base was not repeated. I presume that has been discontinued because you would have easily heard that traffic.
Your setup is probably doing the best as can be expected for a radio having no noise blanker, unless you are using a commercial radio, which would extend your reception range.
Hard to believe CHP has such basic coverage in that heavily traveled stretch as compared to their coverage in other parts of the state. Guessing they might be on a trunked system or communicating cross band. Perhaps they simply have remote receives established in high ground that vote through a comparator to the dispatcher. Just can’t brlieve they don’t have repeater coverage but it is what it is. This is where it gets interesting. Thanks for your response.
CHP is not trunked in that area. Mountaintop receivers at Parker Dam (Black Metal Mountain), Vidal Junction, East Iron Mountain, Desert Center, Chiaraco Summit, Toro Peak, Snow Peak, Cactus City, and Palo Verde Mountains, north of Blythe, are voter received.at Indio dispatch center. There are more radio sites on the west end. The system works well, unless you want to hear the mobiles from any distance.
I-10 east of Indio is a heavily traveled area, however, I noticed in my travels CHP hung around the AZ/CA border and about Desert Center west. In the long area between those points I rarely saw or heard any patrol units.
Try 45.04, 45.18, and 44.98 those are planned new channels for Indio CHP. Maybe some local listeners know if the changeover has occurred.
Another similar deserted patrol area is on I40 between Newberry Springs, east of Barstow, and about 15-20 miles west from Needles. I drove that stretch many times and hardly ever saw a patrol unit or rarely heard any radio traffic.
Good luck!
I-10 east of Indio is a heavily traveled area, however, I noticed in my travels CHP hung around the AZ/CA border and about Desert Center west. In the long area between those points I rarely saw or heard any patrol units.
Try 45.04, 45.18, and 44.98 those are planned new channels for Indio CHP. Maybe some local listeners know if the changeover has occurred.
Another similar deserted patrol area is on I40 between Newberry Springs, east of Barstow, and about 15-20 miles west from Needles. I drove that stretch many times and hardly ever saw a patrol unit or rarely heard any radio traffic.
Good luck!
The CHP radio system is not designed for the convenience of scanner listeners. It relies on mountain top sites that are set up as remote bases. The dispatch center has a voter which will (mostly) provide the best receive and transmit coverage. Repeaters is remote areas have not worked too well because of phase distortion caused by receiving multiple sites at the same time. It really is not possible to synchronize the transmitters well. They do use repeaters in metropolitan ares where a single site gives good coverage.
Receiving CHP cars is limited to a few miles when you are at ground level. Usually the dispatcher relays traffic because the cars can't hear each other either.
A trunked system would make no sense. They are the only users and have no need for talk groups and the like. Moving to a UHF system would require more sites and microwave relays. No trunking on low band anyway.
They will likely stay on low band for a long time. It works for their use better than anything else especially in remote areas.
In my area (Coastal Division) I can't even hear all the dispatch traffic from remote mountain sites let alone the cars.
Receiving CHP cars is limited to a few miles when you are at ground level. Usually the dispatcher relays traffic because the cars can't hear each other either.
A trunked system would make no sense. They are the only users and have no need for talk groups and the like. Moving to a UHF system would require more sites and microwave relays. No trunking on low band anyway.
They will likely stay on low band for a long time. It works for their use better than anything else especially in remote areas.
In my area (Coastal Division) I can't even hear all the dispatch traffic from remote mountain sites let alone the cars.
Thanks for your response that seemingly is correct. Feel sorry for the CHP officers working that beat. Is wht it is.
The main problem for CHP officers on the beat is the inability to hear other cars unless they switch to the base channel. Their range is limited too. I have talked to CHP officers in my area who asked why the dispatcher could hear them, but they could not hear dispatch. The voter reception is not foolproof. Sometimes the path to the receiver site is better than the path back to the mobile. They just have to ask dispatch to change to a different site. The CHP system has not changed much in 60 years. You don't find many semi-duplex operations any more. However, for the distances and terrain they cover it is the best that they can do. The new 700MHz extenders are an improvement. They have also added new sites in this area to fill in dead spots. They are spread very thin. In my area there are only 3 cars to cover the Buellton office in the Coastal Division.
Very interesting and believable. Here in AZ, State Police actually vote UHF repeaters. Usually a mobile can receive a distant repeater that is full quieting to another mobile unit. They complain about that coverage, don’t realize how good they have it. Transiting to a trunked system someday. Thank you for your input.Have a nice day.
Oddly enough, CHP-El Cajon in San Diego County dispatches exclusively on the county 800 trunked system.
On I-15 there is a resident post at Mountain Pass about 20-30 miles from the Nevada border. I wonder if there might be on at Desert Center explaining the concentration of patrols seen in that area.
On I-15 there is a resident post at Mountain Pass about 20-30 miles from the Nevada border. I wonder if there might be on at Desert Center explaining the concentration of patrols seen in that area.
Seems possible but I didn’t notice any 800 MHz antenna’s on the CHP mobiles on the I 10 stretch in question but did receive traffic in 700MHz when near a couple of their mobiles which must have been their new mobile repeaters. I did receive occasional low band dispatch traffic which was in alignment with previous remote base theories. Is possible the dispatcher was multiselecting in low band and perhaps another system simultaneously. Leaning towards a basic low band system that works for them. I love the hunt but there is probably nothing to hunt. Will be rolling through there again soon.
Barstow CHP is the same deal .... very very large area to dispatch.... with the voter system, you don't hear much, unless your in the area.
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