Chp/San Diego co. / rcs vs.vhf low band

[scottyhetzel]

Just curious why chp low band is simacast on rcs ? Does chp units have rcs radios in the 800 MHz band ? Or is this so rcs dispatch can monitor and x-connect 800 TRS system to low band...

[JoeyC]

CHP does not simulcast lo band on RCS.
The El Cajon office uses the RCS as their working radio, so yes they have RCS radios in their cars.

[carlt]

El Cajon does sometimes simulcast GOLD with their normal RCS channel. This would be for special details, poor coverage areas, extra units from other areas (like for fires) that don't have RCS radios, etc.

[scottyhetzel]

Originally Posted by JoeyC

CHP does not simulcast lo band on RCS.
The El Cajon office uses the RCS as their working radio, so yes they have RCS radios in their cars.

Joey, why would el cajon use RCS ?. Why is San Diego so unique compared to the rest of the state ? I'm sure the new 700 MHz extenders can go to simplex 800 MHz access channel for mutual aid. or access the RCS access channel. Not arguing... Just trying to figure out the real reason why ?

[JoeyC]

Someone else might be able to tell you "why" El Cajon uses the RCS, but it does, and has for several years now as their primary radio. They rarely use Gold1 (their VHF Lo freq).
As for the 700mhz extenders, I have yet to hear anything on those freqs.

[scottyhetzel]

Originally Posted by JoeyC

Someone else might be able to tell you "why" El Cajon uses the RCS, but it does, and has for several years now as their primary radio. They rarely use Gold1 (their VHF Lo freq).
As for the 700mhz extenders, I have yet to hear anything on those freqs.

Thanks Joey ! I would assume it sounds great if your are within range of the RCS repeater.

[K6CDO]

Originally Posted by scottyhetzel

Joey, why would el cajon use RCS ?. Why is San Diego so unique compared to the rest of the state ? I'm sure the new 700 MHz extenders can go to simplex 800 MHz access channel for mutual aid. or access the RCS access channel. Not arguing... Just trying to figure out the real reason why ?

In 2002 CHP Border Division (specifically the El Cajon Area office units) came onto the RCS as a pilot project to see how 800 MHz trunking would work in mountainous terrain. Border Dispatch has two RCS consoles in addition to their CHP network consoles.

It has worked well.

[carlt]

Originally Posted by scottyhetzel

"Thanks Joey ! I would assume it sounds great if your are within range of the RCS repeater."

Actually, since they have access to all RCS zones, they can be heard from all over the county, and beyond!

[WayneH]

Originally Posted by carlt

the "edit/delete" button only allows to edit. how do you delete a wrong post?

Click at the upper right of the post and report it to us. We don't allow members to delete posts.

[carlt]

Thanks Wayne!

[musician2111]

Joey the 700 mhz system is not here in the Border Region yet, thus, the El Cajon office remains on the RCS. All of the officers I have spoken to love their RCS handhelds and hate the VHF stuff everyone else has to rely on.

Not sure if this has anything to do with simulcasting or not but the CHP dispatch center uses a single dispatcher for all three offices in the area : San Diego, Oceanside and El Cajon. This seems ludicrous to me. You don't see SDPD using a single dispatcher for every office in the county nor does the Sheriffs Department. However, the fact that a single console has to control both the RCS and VHF systems might be why the programming is as you described. But I am not a radio tech or programmer so I could be off base here .....no pun intended.

[inigo88]

The 700 MHz *HAS* made it here, to the San Diego and Oceanside offices. They are not replacing the whole CHP system with 700 MHz, they are simply replacing the extender repeaters in the cars and the officers aging VHF portables. See the "Vehicular Rario System (VRS)" frequencies in the database.

Pay close attention to the officer's voices on Orange-1 and Tan-1 when they're out on portable, and I guarantee you will hear the familiar warbly sound of digital being patched into analog before too long.

Most of the lowband frequencies are being reworked to allow for simulcasting in areas where it hasn't been implemented yet (SD office already does), but the car radios themselves will remain on analog VHF low band. Whether El Cajon makes the switch from RCS-portables to 700 MHz portables is probably more of a question of politics than anything, but I believe the deadline for the 700 MHz portable radios is next month when VHF narrowbanding takes effect.

Since RCS is an 800 MHz system, and most new 700 MHz portables also cover the 800 MHz range, perhaps El Cajon can have their cake and eat it too?

[carlt]

Originally Posted by musician2111

Joey the 700 mhz system is not here in the Border Region yet, thus, the El Cajon office remains on the RCS. All of the officers I have spoken to love their RCS handhelds and hate the VHF stuff everyone else has to rely on.

Not sure if this has anything to do with simulcasting or not but the CHP dispatch center uses a single dispatcher for all three offices in the area : San Diego, Oceanside and El Cajon. This seems ludicrous to me. You don't see SDPD using a single dispatcher for every office in the county nor does the Sheriffs Department. However, the fact that a single console has to control both the RCS and VHF systems might be why the programming is as you described. But I am not a radio tech or programmer so I could be off base here .....no pun intended.

Yes, San Diego is using the 700 mhz portables. You just need to be within a certain distance of an active unit to be able to hear them.

San Diego DOES have a separate dispatcher on each area channel. You will hear a male on one and female on another, or any combination thereof.

[Anderegg]

The 700MHz extenders seem to operate at extreme distances. I can pick up the 700 stuff a mile away or around corners.....such as I can hear units at 805 and Adams from 8 and 15 as an example.

Paul

[Mike_G_D]

Originally Posted by Anderegg

The 700MHz extenders seem to operate at extreme distances. I can pick up the 700 stuff a mile away or around corners.....such as I can hear units at 805 and Adams from 8 and 15 as an example.

Paul

Well, "extreme distances" is a relative phrase-term in spades! Radio being what it is and propagation of radio waves given various frequencies being what IT is, "extreme" in terms of distance is an extremely (actually no pun originally intended, but hey, ok, whatever!) variable adjective (adverb?, whatever modifier, anyway)!

The extenders are designed for "short range" use but conditions can affect things significantly. Given the 700MHz frequencies involved it wouldn't surprise me if you could hear them over a mile away (and I do, actually) when in clear line of sight or when surrounded by non-inclusive metallic objects such as in urban or semi-urban environments. But in rural areas with heavy vegetation (esp. good ol' pine needles and the like) surrounding the transceiver it's entirely possible that you would have trouble hearing it less than 1/4 mile away. Radio being electromagnetic waves and such waves being particularly fond of certain fractions of their wavelength, especially in halves and quarters, this is perfectly logical.The wavelength at 750MHz is slightly over 15.5 inches and a quarter of that is around 4 inches; pine needles and even water molecules (or large groupings of, at least) look reasonably significant to such wavelengths while appearing nearly non-existent to 42MHz's 23 footer (approx. 6 footer at 1/4 wave) wavelength. This is also why on very foggy/rainy/snowy days 700MHz and higher frequencies can get badly attenuated. On the other hand, large metallic objects can slaughter lower frequencies but effectively "bounce" the really high stuff around enough that, as long as some crazy path is available, they'll get to places you might think unlikely! And yes, certain natural minerals contained in hills and mountains can also reflect and absorb to varying degrees - it might help or it might hurt, depends, on many things. And then there's tropo...

Anyway, yep, you might hear them pretty "far" away, but then again, you might not!

-Mike

[K6CDO]

Originally Posted by Anderegg

The 700MHz extenders seem to operate at extreme distances. I can pick up the 700 stuff a mile away or around corners.....such as I can hear units at 805 and Adams from 8 and 15 as an example.

Paul

The 154 MHz system used very low power (.25 watts from the car, and 1 watt or less on the handhelds) because everybody was on the same channel. Even then, in the multichannel metro areas (L.A., Bay Area, Sacramento, and in spots San Diego) units on differing dispatch channels operating at the edge of their area (such as a San Diego unit on I-5 between Del Mar Heights and Via De La Valle, and an Oceanside unit stopped on I-5 just north of Via De La Valle) could key up both vehicle's extenders resulting in both dispatchers hearing (and sometimes responding to) the transmissions.

With the multiple pairs at 700 MHz this problem is eliminated, so the power levels are closer to the normal 2-3 watts for low power operations, and you can hear the units farther.

[Anderegg]

Hey KaySix, am I correct in assuming the CHP 700MHz handhelds would also do RCS if someone bothered to program them as such?

Am I also correct in assuming all 700MHz radios also do 800?

Also, why is the audio quality of my XTS3000 on RCS exactly the same as my 396XT scanner?

Additionally, would an XTS5000 have louder audio, and could I put CHP extender frequencies in it?

Paul

PS: :-P

[K6CDO]

Originally Posted by Anderegg

Hey KaySix, am I correct in assuming the CHP 700MHz handhelds would also do RCS if someone bothered to program them as such?

Am I also correct in assuming all 700MHz radios also do 800?

Also, why is the audio quality of my XTS3000 on RCS exactly the same as my 396XT scanner?

Additionally, would an XTS5000 have louder audio, and could I put CHP extender frequencies in it?

Paul

PS: :-P

Yes.

Yes.

I don't know.

I don't know, and in theory, yes.

Don

[inigo88]

I think a better question would be, why do you have an XTS3000 on the RCS?

[Anderegg]

It is a news media radio programmed by the RCS with a limited set of talkgroups. Except for the superior reception, it is inferior in all ways to my 396XT.

Paul