CHP 700 MHz Base Station Frequencies

[capturecom]

I would guess that the CHP folks were trying to be ready for all of those Kawasaki C14's that were supposed to be delivered, when they paid the premium for immediate delivery of the motor antennas. With the cancellation of the Kawasaki C14 procurement, and now a re-compete for motor procurements, there are probably more similar situations for more than just antennas. Maybe they'll be back with BMW in the near future.

But, to address the observation from "antfreq" for the traffic on 774.53125 NAC296, a few C14 motors with the new system did manage to escape the confines of the shop, and they are in the field. That would explain what was being heard in SAC on the frequency. I've heard rumors as to the number of C14s deployed statewide, and it covers anything from 14-50 motors....and 50 seems unlikely due to the problems encountered in trying to get VHF Low Band to play on the new C14 motor platform.

Maybe they'll pull some of those "special" Pyramid P750 configurations off the shelf and integrate them into a few R1200RT-Ps in anticipation of going back to BMWs for CHP motors.

 

[ScannerDude244]

I heard from some folks in SAC that all new CHP motors are being equipped with a special Pyramid P-750 unit (P25).

It operates on 774.53125 simplex, versus the duplex VRS System found in the upgraded CPVE cars, and every officer is issued a new EF Johnson 5100ES portable. It appears that it will function similar to the current VHF-H extender system, but P25. And the frequency does appear to be a base channel, which seems to indicate that only offices without motors can effectively use 774.53125 (Construction Zone), once the 700 MHz CHP Base system is deployed.

This morning I was listening to a unit not sure if it was motor unit working the construction zone on the 101 construction Zone

I got these NAC'S

Base: NAC 296
Mobile: NAC 303
Car to Car: Nac 404

 

[scottyhetzel]

Has anyone is Southern Cali heard any traffic on the office 700 mhz extenders ? I am just curios how far the office antenna transmits. Its a bummer to listen to low band on a portable ..i much rather listen to a 700/800 band on my portable .

 

[russianspd]

Up here in North I haven't heard anything on the VRS or Extenders. All been Mobile and Base for me.

 

[rananthony04]

Has anyone is Southern Cali heard any traffic on the office 700 mhz extenders ? I am just curios how far the office antenna transmits.

Just once a couple of months ago on the Orange(Baldwin Park). It was a 23103 broadcast. I should mention that I heard this on their primary 700Mhz "extender" freq.

 

[bcorbin]

Has anyone is Southern Cali heard any traffic on the office 700 mhz extenders ? I am just curios how far the office antenna transmits. Its a bummer to listen to low band on a portable ..i much rather listen to a 700/800 band on my portable .

By which you mean the 700 MHz base frequencies? The Newhall office seems to have a range of roughly 3-5 miles, line-of-sight.

For what it's worth, I managed to catch a motor, a couple of months ago, on the 700 MHz base frequency that started this thread... So at least one of the bikes made its way to West Valley...

 

[bcorbin]

So... From the looks of database entries, the CHP is re-vamping its 700MHz lineup... Anyone care to fill us in on how this is supposed to work?

I guess I'm a little confused... As I understood it, the base system was to be used as a local extender in and around the general area of a station. I'm guessing that moves to 'Base Extender' now. So we can expect the stations and inspection areas currently equipped to be making a move soon?

But then, what are the 14 base station frequencies and 2 base station tacs? Are these actually not so much base frequencies as base-assigned frequencies for use as needed in the field? Seems a little strange not to refer to them all as TAC's then...

Ah... unless the division-wide base is something like a 700 MHz Blue, the 14 base station frequencies are parceled-out among the stations, and the extender is.... for inspection areas and such? The 2 tacs are assigned by base as needed, ... Alright, maybe I can see how this is going to work. But that means installing a bunch of high-level 700MHz infrastructure for the division-wides... ?

...just curious...

 

[inigo88]

So... From the looks of database entries, the CHP is re-vamping its 700MHz lineup... Anyone care to fill us in on how this is supposed to work?

I guess I'm a little confused... As I understood it, the base system was to be used as a local extender in and around the general area of a station. I'm guessing that moves to 'Base Extender' now. So we can expect the stations and inspection areas currently equipped to be making a move soon?

But then, what are the 14 base station frequencies and 2 base station tacs? Are these actually not so much base frequencies as base-assigned frequencies for use as needed in the field? Seems a little strange not to refer to them all as TAC's then...

Ah... unless the division-wide base is something like a 700 MHz Blue, the 14 base station frequencies are parceled-out among the stations, and the extender is.... for inspection areas and such? The 2 tacs are assigned by base as needed, ... Alright, maybe I can see how this is going to work. But that means installing a bunch of high-level 700MHz infrastructure for the division-wides... ?

...just curious...

I don't think there is such a thing as a 700 MHz Blue equivalent. The 700 MHz base frequencies have simply been split up based on which base frequencies you'll likely see used in which division. Right now the 700 MHz base frequencies and VRS frequencies are duplicated in two places. You'll see them listed by division or area office, and again near the bottom of the page in the complete list of all VRS and base frequencies. We're in the process of deciding the best and most user friendly way to present this.

I believe the 700 MHz frequencies will go like this:

* VRS (Vehicular Repeater System) - Replacing the existing VHF extenders to link the portables to the mobile vehicle radios.

* 700 MHz Base - Acting as a local area office "extender" to allow the officers at the station to communicate on the dispatch frequency using only their portables. The 700 MHz base tacs will presumably be for portable-to-portable communication.

* There's also a 700 MHz base frequency assigned for Air divisions, which will be the same as the area offices just located at the airport where the aircraft are based. They will also eventually transition the weigh stations to 700 as well.

It's not a terribly complicated system, they're just using 700 MHz frequencies as "cross-band repeaters", to tie the officer's portable radio into a lowband base station. (It's not a true crossband-repeater but rather allows the portables to remotely control the base station radio, just like the vehicle extenders currently do.) Where that base station is located (i.e. the local area office, or a weigh station, or an air division hangar at an airport) and which division it's in determines which 700 MHz frequency will be used. Hope that helps.

 

[bcorbin]

Clear as mud - but not for any fault on your part, thanks for the followup 8*) I think I'm just over-thinking this.

If the range of the base-extender at Newhall* is typical, you could probably put every station in the state on the same channel and never have a problem. 'Base Extender' seems like a pretty good candidate for that.

But if the local station is set up on 'Base Extender', it's not on the division-wide common... if it's on the division-wide common, it's not listening to 'Base Extender'. So these assignments seem to be a bit at odds with one another, unless one or the other channels is not actually being used as a base-extender.

Apart from aesthetics, I'm not sure I understand what assigning base-extenders to different channels by division does for anyone, either. There is ~zero potential for inter-divisional interference from base extenders.

14 base channels (some assigned by division), 2 tacs, an air-base assignment, *and* a base-extender... It looks like a) there's a lot more going on here than just the base-extenders and b) labeling the channels ' Base (whatever) ' might be a misnomer. It'll be interesting to see how this is actually utilized and/or how long this code-plug lasts 8*)

Despite having thrown the idea out in my previous post, I don't believe we'll see a 700MHz Blue (since they can access low-band Blue easily enough via VRS) - that's why the division-wide assignments intrigue me...

Of course, wasn't this all drafted by the same guys who added more frequency pairs than their low-band radios could handle? Maybe I'm expecting a little too much 8*)


===
*For those in a position to check it out, Newhall's base-extender has been operational on 773.53125 for quite some time. In the old line-up, that was "Base 1" - now it appears it is/will be "Base Tac 1".

 

[WayneH]

For those looking for 700MHz extender discussion please contain it in the thread below. We would prefer not having to move more posts out of this thread again. Thanks.

http://forums.radioreference.com/california-radio-discussion-forum/298556-chp-vehicle-extenders.html

 

[SCPD]

bcorbin's observation that one base station extender frequency for the entire state is a good one. I can't think of a situation where there are two area offices within the 3-5 mile range of a base station extender as posted above, either in the same division or two different divisions. The latter seems the most likely to apply to the need of having varied base extender frequencies assigned to each division. I don't have the 90+ area offices memorized, but I don't recall area offices either within the same division or different divisions being that close.

There is another possibility. The CHP may not have statewide authorization for one or all of these extender frequencies. That would require the use of one extender frequency for each division in the state. It would depend on the 700 MHz licenses for other agencies in each division and if other license holders within a division would experience harmful interference from the CHP's use 3-5 miles around each area office.

I have some other comments and possible extender scenarios regarding the low band base stations in each area office. This may affect how the extender frequencies are used and assigned. I assume that the base station in each office is one radio and the use of the blue and the tactical frequencies is accomplished by someone at a console using a frequency button or switch. At that point everyone else in the office has to listen to that blue or tac through the speakers mounted throughout the office. The use of the blue or tac might only involve the area's captain/lieutenant, a sergeant and an officer or two working on one incident requiring their involvement. I assume there aren't different radios dedicated to each frequency (blue and tacs) What happens when the rest of the station or one/few officer(s) needs to listen to the area office frequency? Do they then use their vehicle extender? What if all the vehicles assigned to that office are on the road? Or what if the only vehicle at the office are assigned to the captain/lieutenant and the radio in it is not turned on.

If there is more than one base station radio at the station, one dedicated to the blue and one dedicated for each of the tactical frequencies used by that area office, can a different base station extender channel be used to control each of those bases? I can't imagine multiple base stations installed at each area office, but how would I know? There is a different radio for each band in each of the new patrol vehicles as I understand. If there are multiple base radios this could explain why there are additional base station extender frequencies authorized throughout the state. However, wouldn't there be a division base extender secondary extender frequency listed or licensed if this was the case?

These are a lot of possibilities to explain why there are different base extender frequencies assigned to each division. However, if the CHP has statewide licenses for all of the extender frequencies then one statewide base extender primary frequency and a set of a few more secondary base extender frequencies could be assigned and be common to all divisions.

Several members have a good working knowledge of the CHP's radio system and have more insight than I do.

 

[bcorbin]

Actually, there is a big chunk of 700 MHz (~96 pairs) set aside specifically for state licenses and they are buffered from local allocations by reserve and interoperability pairs. I don't think there's anything in that allocation that can't be used statewide, and one would think that most would be assigned on a statewide basis.

The bandplan, as presented, still doesn't make a whole lot of sense to me if 700 MHz is intended to be used primarily for very low-level repeaters/extenders...

[...]

There is another possibility. The CHP may not have statewide authorization for one or all of these extender frequencies. That would require the use of one extender frequency for each division in the state. It would depend on the 700 MHz licenses for other agencies in each division and if other license holders within a division would experience harmful interference from the CHP's use 3-5 miles around each area office.

[...]

 

[bcorbin]

I've made a few short trips over the last couple of months up to points in Valencia where I should have been able to hear Newhall's base-extender, at times where there should have been plenty of activity - and... there hasn't been any. Nothing heard on any of the CHP base-extender frequencies. So either they've gone off the air, moved to another of the state's allocated frequencies, or I've been amazingly unlucky...

 

[scottyhetzel]

Well keep scanning... Next time just eat your lunch in the chp parking lot and close call it with a digital scanner...you will have a better chance..

 

[w9xxx]

I randomly hear both sides of conversations on 700 throughout the state not over mobile repeaters. Most are "office" type of conversations. I think some remote bases are running. I hear lots of 700 on I-15 north of Barstow some days. Other days I wont hear a word while I've passed 4 or 5 CHPs on that road.

 

[hotdjdave]

154.905

So then what will happen to the 154.905 mobile extender channel? Will it be replaced by the new 700/800 Mhz plan?

 

[ScannerDude244]

So then what will happen to the 154.905 mobile extender channel? Will it be replaced by the new 700/800 Mhz plan?

It's been replaced for a few years already. Their is only a few or none at all 154.905 mobile extenders left out there. I wonder what the state is going to do with that frequency.