CHP 700 MHz Extenders

[Sac916]

Downtown Sacramento Valley Division Black Radio. Right now monitoring 2 CHP Motor units and a CHIP patrol car. They're parked right outside my home for their meal break. Captured 774.53125 NAC 296. Watching them for over 40 minutes now. Noticed that every time their radio keyed and I heard audio, a bright green LED would light up on their portable radios. It lit up for TXT/RX. Also noticed that while in standby mode, NAC 682 would show up, as if this was the radio silently communicating. Maybe a datastream?

Just now a motor unit keyed up to talk on Black radio and 774.53125 had NAC 303

Sent using Tapatalk 2

 

[officer_415]

Downtown Sacramento Valley Division Black Radio. Right now monitoring 2 CHP Motor units and a CHIP patrol car. They're parked right outside my home for their meal break. Captured 774.53125 NAC 296. Watching them for over 40 minutes now. Noticed that every time their radio keyed and I heard audio, a bright green LED would light up on their portable radios. It lit up for TXT/RX. Also noticed that while in standby mode, NAC 682 would show up, as if this was the radio silently communicating. Maybe a datastream?

Just now a motor unit keyed up to talk on Black radio and 774.53125 had NAC 303

Sent using Tapatalk 2

Sounds like the motorcycle extenders they were talking about in the other thread: http://forums.radioreference.com/ca...mhz-base-station-frequencies.html#post1815301

 

[KMA367]

Secret squirrel frequency?

Interesting observation tonight in Humboldt. I came across a just-occurred TC near Eureka and awaited CHP's arrival, which they promptly did, two units. Initially one unit was TX'ing on the Green via the extender on their established VRS Ch 1, 769/799.16875.

After he left, the remaining officer was also talking into a portable (couldn't get a look at it, too far and too dark) and his car radio was repeating it on low-band, but the portable wasn't TXing on any of the VRS channels, nor on their traditional (and presumably now "unauthorized" due to its not being narrowbanded) 154.905. I was scanning all 32 mobile and base 700 VRS freqs, the 16 "Future 700Mhz Base Radio System" frequencies in the RR database, and using my close-capture for all bands from perhaps 50 feet away. I heard neither the officer nor dispatch on anything but 42.24 and 42.54, respectively. This went on for 20 minutes or so, with several sets of radio conversations with HMCC.

Any ideas on what this guy might have been using? I passed the Arcata CHP office on my way home afterward and my scanner was picking up VRS 1 loud and clear, from several hundred yards away, so it wasn't a scanner problem.

 

[zerg901]

Secret squirel freq? - Any chance you had some freq locked out of your scanner? Would close call get a 220 Mhz freq? How about the ~166 Mhz dashcam audio freqs? Any chance they have a special authorization to use some unused TV channels? What scanner were you using? What bands does the Close Call cover?

 

[KF7RAY]

Did you try any of the remote links at the bottom of the page?
Department of the Highway Patrol (CHP) Scanner Frequencies and Radio Frequency Reference

 

[KMA367]

Secret squirel freq? - Any chance you had some freq locked out of your scanner?

After 154.905, that was the first thing I checked for when I saw the officer using his HT but heard the transmissions only on 42.24 / 42.54, just minutes after I'd heard the first officer on VRS 1. I have a 50-channel bank dedicated to the CHP's "documented" 48 700-band frequencies (24 pairs). I quickly toggled through this "CHP-700" bank, and all 48 channels were unlocked, FM, and CSQ.

Plenty of other programmed frequencies and banks were locked out, but the Close Call would have snagged them. I was in a quite quiet RF area and the CC stopped on nothing other than the Sheriff and CHP frequencies in use at the scene

Would close call get a 220 Mhz freq?

Not on either scanner I had with me. The Pro-83 doesn't receive 220, and the Pro-96 would receive it, but it doesn't have close call. I have no 220s programmed in.

How about the ~166 Mhz dashcam audio freqs?

Close call would pick them up at that distance, although I've never seen a dash camera in a CHP Humboldt area car nor picked up any of those frequencies around here.

Any chance they have a special authorization to use some unused TV channels?

There's always a chance, though I know of none, nor any reason they would need one in an individual car on the rural north coast

What scanner were you using?

Pro-84 (analog only) and Pro-96 (analog/digital)

What bands does the Close Call cover?

Analog only (the Pro-84) between

• 25.0000 - 54.0000
• 108.0000 - 136.9875
• 137.0000 - 174.0000
• 406.0000 - 512.0000
• 806.0000 - 956.0000 (except cellular of course)

all five of which are selected "in."

Other than the challenge of gathering the information (typical scannerhead attitude? :roll: ), I have almost zero interest in monitoring their extender frequencies.

 

[KMA367]

Did you try any of the remote links at the bottom of the page?
Department of the Highway Patrol (CHP) Scanner Frequencies and Radio Frequency Reference

No I didn't, but other than the 72-75 mHz frequencies my Close Call would have picked them up, as near as I was to the guy.

The closest remote sites themselves (Camp 6 and Hazel View) are about 75 miles from the scene, and 65 miles from where I live - with literally nothing but mountains in between - and in 22 years here I've never heard a peep from them. Assuming they're still in use, they would be for Crescent City (#95) units.

I'm trying to wrap my mind around how or especially why those frequencies might be used with an extender rather than 154.905 or the 700s.

 

[selgaran]

Analog only (the Pro-84) between

• 25.0000 - 54.0000
• 108.0000 - 136.9875
• 137.0000 - 174.0000
• 406.0000 - 512.0000
• 806.0000 - 956.0000 (except cellular of course)

all five of which are selected "in."

Other than the challenge of gathering the information (typical scannerhead attitude? :roll: ), I have almost zero interest in monitoring their extender frequencies.

Doesn't look like your close call list would have covered the 700 MHz frequencies, so if the portable was using a 700 MHz channel that wasn't in your scan list, I don't see how your close call would have picked it up.

 

[KMA367]

...and possible FCC waiver enroute for 154.905 wideband?

Doesn't look like your close call list would have covered the 700 MHz frequencies, so if the portable was using a 700 MHz channel that wasn't in your scan list, I don't see how your close call would have picked it up.

You're exactly right, selgaran, but Peter asked for the Close Call bands so I listed them. And not only no 700 coverage, but the Pro-84 doesn't do digital anyway, which is why I prefaced the requested band list by noting "Analog only (the Pro-84) between..."

It was just a coincidence that I even happened to have the Pro-96 with me that evening, as I rarely carry it around. There's nothing digital (or trunked, for that matter) in Humboldt County public safety other than these new CHP freqs, so any scanner built in the last 35+ years works just fine for 99% of my listening interests. The '96 is mainly my traveling scanner.

And this just in from the proverbial "reliable source" that the CHP has supposedly received verbal notice that they're getting a one-year FCC waiver to continue using 154.905 in wideband. Nothing in writing or in the FCC databases as of this evening, but if so that'll take much of the pressure off getting the 700 rigs installed in all their vehicles.

 

[bcorbin]

The 72-75 MHz link frequencies are strictly point-to-point, you're not going to have portables there. If anything was ever tested on 220 MHz, I doubt it got out of the lab. Anything in an unused TV channel would likely require a waiver and a *highly* customized portable/trunk-deck unit. The probability of any of those ideas panning out is nil, or darn close to...

Occam's razor. Always look for a simple solution. The CHP has a lot of 700 MHz portables, presumably an essentially equal number of 700 MHz trunk deck units, and about 85 frequency pairs (from which the VRS and Base frequencies are drawn) that the state can use with implicit license. Scan over the 700 MHz pairs allocated to state use...

 

[KMA367]

The 72-75 MHz link frequencies are strictly point-to-point, you're not going to have portables there. If anything was ever tested on 220 MHz, I doubt it got out of the lab. Anything in an unused TV channel would likely require a waiver and a *highly* customized portable/trunk-deck unit. The probability of any of those ideas panning out is nil, or darn close to...

Occam's razor. Always look for a simple solution. The CHP has a lot of 700 MHz portables, presumably an essentially equal number of 700 MHz trunk deck units, and about 85 frequency pairs (from which the VRS and Base frequencies are drawn) that the state can use with implicit license. Scan over the 700 MHz pairs allocated to state use...

I just happened to be at the right place at the right time with the right radio and tried to take advantage of it. CHP calls around here are so sparse, and distances are so great that I'm not going to even try to track it down. When they get their poop in a group, either I or someone else will figure it out. It's not like it's their dispatch or other "gotta have it" frequencies.

 

[bcorbin]

I just happened to be at the right place at the right time with the right radio and tried to take advantage of it. CHP calls around here are so sparse, and distances are so great that I'm not going to even try to track it down. When they get their poop in a group, either I or someone else will figure it out. It's not like it's their dispatch or other "gotta have it" frequencies.

I totally understand. No, the reason I posted it was to try to limit the general speculation/investigation to bands that were likely to be productive. I can't imagine that there are too many configurations set up outside the normal band-plan - stumbling on one, anywhere, is going to be rare, and if one is looking in the right place, they've got a much better chance of finding it...

I'm on the freeway at least 3 hours a day (needless to say, I'm a bit envious) - I can keep a radio rolling over the state freqs and if something unusual pops up, I'll report back...

 

[zerg901]

The Pro 84 would have given you a hash noise if it was receiving a digital signal - right?

Maybe they were using a 700 Mhz mutual aid channel for the MO3. I have seen many listings for the 800 Mhz mutual aid channels being used as a simplex channel (LAFD as a prime example).

 

[K6CDO]

The Pro 84 would have given you a hash noise if it was receiving a digital signal - right?

Maybe they were using a 700 Mhz mutual aid channel for the MO3. I have seen many listings for the 800 Mhz mutual aid channels being used as a simplex channel (LAFD as a prime example).

Peter,

The CHP has at least 2 dozen 700 MHz State License pairs assigned for just 700 MHz extender use. Use of a nationwide Mutual Aid channel for MO3 operation is a violation of State mutual aid use policies.

(LAFD has the 800 MHz mutual aid channels for multiple-agency operations. Single-agency use would also be a violation.)

Don

 

[bcorbin]

The 72-75 MHz link frequencies are strictly point-to-point, you're not going to have portables there. If anything was ever tested on 220 MHz, I doubt it got out of the lab. Anything in an unused TV channel would likely require a waiver and a *highly* customized portable/trunk-deck unit. The probability of any of those ideas panning out is nil, or darn close to...

Occam's razor. Always look for a simple solution. The CHP has a lot of 700 MHz portables, presumably an essentially equal number of 700 MHz trunk deck units, and about 85 frequency pairs (from which the VRS and Base frequencies are drawn) that the state can use with implicit license. Scan over the 700 MHz pairs allocated to state use...

Well... What do you know... I was scanning over the state frequencies not assigned to CHP VRS/Base and got a hit. Unfortunately, it was a one-off transmission, I didn't get to the radio fast enough to punch pause and grab the frequency, and I can't say for absolute certain it was CHP - but... I can say there's life on the state 700 freqs beyond the circulated lists... Definitely worth watching...

 

[zerg901]

Arent there a couple of the 700 Mhz mutual aid channels that are dedicated to MO3 or FB2T use?

 

[K6CDO]

Arent there a couple of the 700 Mhz mutual aid channels that are dedicated to MO3 or FB2T use?

... as interoperability (multiple agency use) channels, yes, FB2T use is allowed on any of them.

Single-agency MO3 use (such as extender use) is a whole different story.

 

[scottyhetzel]

Arent there a couple of the 700 Mhz mutual aid channels that are dedicated to MO3 or FB2T use?

Hi Zerg.. What is MO3?? FB2T ??

 

[Radio_Lady]

MO3 = Vehicular Repeater
FB2T = Temporary Mobile Relay

 

[capturecom]

VRS Installs W/O CPVE Suite - Inland

This may not be new news for most, but I've recently seen two different older vehicles out of the Victorville Office (Inland White) that have been equipped with 700 MHz VRS, but without the CPVE suite. Just the 700 MHz extender integrated with the conventional VHF Low Band radio. The 154.905 extender has been removed, and officers are carrying their new 700 MHz handhelds. The radio traffic on 154.905 has been extremely light in the past two weeks or so, as monitored from Wrightwood, and it would seem that the CHP found a way to become compliant with the narrow banding mandate.....by expediting VRS-only deployments and removing the old extenders.