CHP Digital / Air 8

[HappilyRetired]

Please don't get angry with me for asking this. When I first joined I tried to ask if CHP was going digital and the encounter was not very friendly. I was reading information off the internet and annoyed people that I was trying to learn.

This happened five minutes ago on the Copper - San Bernardino. I have an analog only scanner connected to a low band antenna outside. CHP Air 8 came up and the dispatcher told him he was unreadable. That's because he was digital! He sounded as if he was going through a repeater. I couldn't punch it into my digital scanner quick enough and he didn't reply again. I'm also familiar with it on our Rovers. He was clearly digital. I've heard it enough at this point to know because he sounded like the garbled digital when they're not quite making it into the system. I hope I described that well enough.

I'm afraid to ask this question because of the first time. Is CHP going digital? Or is there perhaps a frequency that ties in to the Copper that would have caused Air 8 to be in P25 mode? I thought maybe the dispatcher had punched up a frequency and accidentally had it tied in. I don't know about that one because she was surprised and said he was unreadable.

I have seen a UHF frequency of 460.375 or 460.450 that has the capability of analog or P25. I didn't know then at LAPD what the frequency was but if we were out of Los Angeles and noticed a DUI driver or something on the freeway we would come up with our unit number and talk directly to LACC or Inland or in some cases Ventura. Sometimes we'd even run a plate. Down here where I'm at I don't always hear the helicopter when they're over a pursuit up in San Bernardino. As a pilot I know that they use low-powered radios because at that altitude they would cover a great deal of area.

I don't want to add too much to this because then you'll just get mad at me for guessing.

 

[f40ph]

Some of these guys are "know-it-alls" on here...the ones getting mad need to take their meds.

CHP has been digital P25 between their vehicles and portables for a few years (this is referring to their 700mhz portable APX radio going through their vehicle extender.) Perhaps that was patched in somehow incorrectly?

Yes their Low Band primary system is analog but don't say "CHP will never go digital".

 

[f40ph]

But, remember "digital" doesn't necessarily mean "encrypted". Start talking encryption - THEN everyone gets their "you-know-what" in a wad.

 

[marcotor]

I think the confusion comes when someone asks a question expecting a hard yes/no answer.

CHP has no plans at this time to switch the full time dispatch on low band to VHF/UHF/700/800 or DMR/Tetra/OpenSky/NXDN/P25/Trunking. Most of the units, and all of the Air units have capabilities to speak with other agencies, which of course includes P25. So if your question is does CHP have the capability to use digital modes, the answer is yes. Is the dispatch and everyday chatter going over there? No.

 

[HappilyRetired]

Some of these guys are "know-it-alls" on here...the ones getting mad need to take their meds.

CHP has been digital P25 between their vehicles and portables for a few years (this is referring to their 700mhz portable APX radio going through their vehicle extender.) Perhaps that was patched in somehow incorrectly?

Yes their Low Band primary system is analog but don't say "CHP will never go digital".

Thank you very much. I was really afraid I was going to get hammered again. I asked a question several months ago about the new Kenwood radio stacks I guess they're called and if CHP was going to go digital. I'm thinking if everybody else is going digital by federal mandate how would CHP be any different? Didn't I read somewhere that they're California Department of Justice as requiring all law enforcement agencies to go encrypted? I keep saying digital but isn't that the next step? I know they don't have to be digital to be encrypted and vice versa. I remember a lifetime to go being in basic training and getting a pass and the taxi cab drivers had scanners. But the police had something that flipped their words upside down. So the taxi cab drivers had a thing that flipped them right side back up again. If you rode in the taxis long enough you could actually kind of do it in your head kinda.

I guess it could have been Air 8 on their handheld frequency. I never thought of that.

I guess this is an open question for non Californians. But nationwide aren't there a lot of County Sheriff's or Highway Patrol's that have a big area to cover that are still on low band? They only have from what I read Kenwood to buy from. If Kenwood can put digital/enc in all their other radios who's to say they can't put it in low band? I hope that day doesn't come.

 

[marcotor]

Ok, so your question has now turned to forecasting and speculation, and I believe that is where the other thread went South. Kenwood offers digital options in their low band radios, and have for some time. If you want to speculate and conjure, that's fine. But that is far from the original "Is CHP going Digital" question.

 

[AM909]

... California Department of Justice as requiring all law enforcement agencies to go encrypted? ...

There's a document on the subject that's published in one of the threads on the subject, but I don't know if we know anything about the timetable. I know that other deadlines, when it comes to law enforcement, routinely get extended when agencies can't comply in time or within budget (e.g. narrowbanding and LASD). Also, the mandate is not that they encrypt all communications; it's that multiple pieces of personal information that can be used to steal someone's identity (e.g. DL number and full name) cannot be voiced in the clear. There are many ways around this, like using MDTs for that stuff (easier/better/faster and better use of dispatch resources anyway), while still using unencrypted (even analog!) voice for routine dispatch traffic and non-sensitive info (e.g. LASD again). I, for one, am happy that, should someone run a 27/28/29 on me, reasonable steps are taken to protect my personal info from prying ears. It's a strange new world.

Now when are they going to encrypt medical paging?

 

[HappilyRetired]

There's a document on the subject that's published in one of the threads on the subject, but I don't know if we know anything about the timetable...

Thank you for helping me learn. I know when I was on the job we were encouraged to use our in MDT's as much as possible. Currently I'm sure you know that CHP routinely runs wants and warrants over the are but as you suggest that could change. I don't want to get any further off-topic because I've already been scolded once.

I remain curious why Air 8 came over as P25 on low band VHF. Could it possibly be that each station now has a 700mhz base station that is P25 that may be linked to their dispatch channel? Perhaps the air unit came up on that. I'm guessing cuz I don't know. I know that they have dispatch consoles in their stations that look similar to what we had and maybe the station punched up a link.

 

[AM909]

I remain curious why Air 8 came over as P25 on low band VHF. Could it possibly be that each station now has a 700mhz base station that is P25 that may be linked to their dispatch channel? Perhaps the air unit came up on that. I'm guessing cuz I don't know. I know that they have dispatch consoles in their stations that look similar to what we had and maybe the station punched up a link.

I don't know, but I wouldn't think the helos would have any need for an extender and, therefore, no need for a 700 handheld. As you know, the extenders are designed for extremely short range, and putting one up in the air would seem to be a bad idea.

No idea why you would hear something sounding like broken digital, but I don't think there's enough info to know.

What little traffic I've ever heard on the two 460 channels has come from the repeaters (e.g. Snow Peak) and has been analog.

 

[HappilyRetired]

I don't know, but I wouldn't think the helos would have any need for an extender and, therefore, no need for a 700 handheld. As you know, the extenders are designed for extremely short range, and putting one up in the air would seem to be a bad idea.

No idea why you would hear something sounding like broken digital, but I don't think there's enough info to know.

I've been in my share of CHP stations. They have Motorola communication centers that are multi-channel. I could tell by the lights that they were similar to what we had at our stations. You could patch channels together. Each station has a 700 MHz simplex P25 base now. They may have had that patched for whatever reason to their analog low band and the air unit came in on the station. Not a mobile extender. Maybe the air unit came in through the station for some reason. But it was gobbledygook P25 that was not decoding.

I'm going to irritate somebody if I keep trying to figure this out in this group so I will leave it at that. It's just my nature to try to figure things out.

 

[chrismol1]

I'll throw out something to add to the speculation. These helicopter radios are multiband everything and every band low/vhf/uhf/700/800/AM/FM/P25. It could be something such as the pilot changed channels but left the mode in P25 instead of changing to FM

 

[HappilyRetired]

I'll throw out something to add to the speculation. These helicopter radios are multiband everything and every band low/vhf/uhf/700/800/AM/FM/P25. It could be something such as the pilot changed channels but left the mode in P25 instead of changing to FM

Occam's razor. The simplest answer is usually correct. That was my first thought. The only thing that threw me from that is people saying that low band doesn't do P25 and I'm thinking why not? As in the famous phrase, "We have the technology." LOL.

 

[marcotor]

You keep saying there is no low band P25, like it is a fact.
For your enjoyment, the Service Manual page one and three for the Kenwood NX Series, LOW-BAND P25 CAPABLE mobile radio.



Now, you can play "what if" to your hearts content

 

[kj6psg]

As you know, the extenders are designed for extremely short range, and putting one up in the air would seem to be a bad idea.

It's actually the other way around. CHP has low level extenders that air units can reach from up there. As far as I can tell, they all transmit on the same frequency and NAC (773.33125 $F7E), so I'm not sure how well reception from the air works.

I'd imagine that CRIS would have the capability of patching into CHP channels if not demonstrated already, but CRIS coverage is nothing like lowband and will fail to cover much of what CHP patrols. Given lowband equipment supply issues, if CHP had a better option, they'd have switched to it years ago. CRIS just helps agencies talk to each other.

 

[HappilyRetired]

It's actually the other way around. CHP has low level extenders that air units can reach from up there. As far as I can tell, they all transmit on the same frequency and NAC (773.33125 $F7E), so I'm not sure how well reception from the air works...

That's pretty interesting. I know the units have extenders but I didn't know that they had extenders located around the service area just for the helicopters to use. That's pretty interesting. But what is CRIS?

 

[kj6psg]

But what is CRIS?

CRIS, or California Radio Interoperable System, is a statewide system of trunking sites set up by Cal-OES as basically a standardized and high capacity version of existing interop channels. Sites are standalone (so far) but all link back to Sacramento. There's been a lot of speculation on other, more appropriate, threads about who may be using it, but CHP has been seen on it, and many of CRIS's channels have come out of the freakishly large CHP conventional channel pool.

 

[HappilyRetired]

I looked it up but I see that they also have CMARS and CRIS on 800 which if I'm reading correctly is best in metropolitan areas. But of course CHP has a lot of mountain and desert area suggesting a hybrid system? I know from my ham radio teachings that low band is more susceptible to skip which is one reason LA County Sheriff moved. It looks like the State has a very large infrastructure of VHF high band and 800. I guess there's nothing left to license? Too much to comprehend. Now my head hurts.

It still doesn't answer the initial question of why Air 8 was on P25 and somehow patched into the Copper. That's okay. I'm starting to get some of this so I'm going to suggest that if the dispatcher could not understand him because he was garbled P25 (he wasn't decoding) that would mean he was coming in on low band P25. If it were a link he would be coming in as decoded audio, right? Have I got that correct?