Question for CHP

[dasmi]

I was listening to the CHP in San Diego today, and someone made a felony stop. Until the officer advised he was code four, there was a tone every few seconds. When he said he was code four, the dispatcher said she was turning off the tone. What's the tone mean?

[tgriffin]

Keep the channel clear.

[leitung]

Might be the beeper, they sound evert 20 seconds or so to remind people to keep the air clear..

Correct me if I am wrong, just a guess..
I listen to the scanner 24/7 in my area, I like to know what is going before the cops show up.

[dasmi]

Yeah, I think it was about every 15 or 20 seconds. By the way, thanks, CHP for not going to a trunked or digital system yet, otherwise I'd have to drop money on a new scanner :)

[jasilva]

Yeah, I think it was about every 15 or 20 seconds. By the way, thanks, CHP for not going to a trunked or digital system yet, otherwise I'd have to drop money on a new scanner :)

They have in Norcal, I'm really suprised they don't have one in San Diego.:confused:

[BigDogatPlay]

Where in Norcal is CHP operating a trunked or digital system?

[Glock Fan]

How do you listen to what they say on the radio? what kind of scanner do you need to buy? i live in OC. are they on a special system?

[Spyder]

Ya, pretty sure NorCal is using the same system as those chippies in SoCal. We use their system as well...but I haven't really learned much about it yet so I couldn't give you any details.

[jasilva]

Where in Norcal is CHP operating a trunked or digital system?

The SF bay area, everything dispatches from the Benicia center. I assumed it was a trunked system as you can not track them with a scanner. You can usually get the dispatch but not the cars unless your line of sight to them. Also the local PDs have to have calls relayed by dispatchers when working with CHP. But this is all second hand info from my dad, he's big on the scanner and ham radio stuff, I deaf enough that I don't need the frustration of trying to follow radio calls.

[leelaw]

Tone: emergency traffic only

Code 4: Clear, no further assistance needed

Where were you listening to both sides of the CHP channels? Those are notoriously hard to hear because they require the vehicle to be nearby, and the radio/scanner to trunk to the channel dispatch is operating on.

[dasmi]

Tone: emergency traffic only

Code 4: Clear, no further assistance needed

Where were you listening to both sides of the CHP channels? Those are notoriously hard to hear because they require the vehicle to be nearby, and the radio/scanner to trunk to the channel dispatch is operating on.
Yeah, I can get both.

[Oshiat]

They have in Norcal, I'm really suprised they don't have one in San Diego.:confused:

I listen to CHP in Fairfield all the time

Dispatch 42.6000 PL 131.8
Car to Station 154.9050 PL 173.8
Car to Car 154.9050 PL 156.7 (i think)

[ANDREWMENDEZ]

Tone: emergency traffic only

Code 4: Clear, no further assistance needed

Where were you listening to both sides of the CHP channels? Those are notoriously hard to hear because they require the vehicle to be nearby, and the radio/scanner to trunk to the channel dispatch is operating on.

1 is generally just for the officers to talk to each other (close range), and the other used for communicating with the dispatcher. Keeps them clearer!!

[KJS]

What scanner setup do you use? My dad had a scanner when I was growing up and it was pretty bad-***. I remember picking up cordless phone conversations, back before they were digital.

[Oshiat]

What scanner setup do you use? My dad had a scanner when I was growing up and it was pretty bad-***. I remember picking up cordless phone conversations, back before they were digital.

Mines a Radio Shack Pro-162, its discontinued so you can get them new for $130 at the RS. It won't do digital but picks up tons of other stuff, the wife actually has gotten into it a little bit also.

[leitung]

I have CHP in sacramento as 42.1200 and 42.2000. I mainly listen to Sac Sheriff north on the County trunked system ID 61552. Thankfully I know all of the 9 codes so it makes it easy for me to understand. It's funny because my dad listens to it and doesn't understand the traffic one bit. Like the other night...

"BEEP BEEP.. all northwest sector units, 415-G in progress, (insert address), henry-23, sam-23, henry-12 respond code 3"
"henry-23 924"
"sam-23 924"
"henry-12 924"
"Control from STAR 5 do you need cover?"
"Afirm"

I am sitting infront of the scanner bouncing around like a retard going "action!" "action!"

Soon after,
"henry-23 906, I got one running, 1 HMA, northbound from Palm"

Me: Hell yeah, go get em!

My dad: (I swear he sounded just like towelie) "I have no idea whats going on..."
It takes getting used to listening to it, and really paying attention to whats going on. You also need know the codes. Thats part of it.
I run a Uniden BC898T 500 channel scanner with Trunktracker III. I have a discone antenna on a 5 foot pole on the roof of my shed.

[leitung]

A Beginner's Guide to the CHP Radio System:
The CHP employs two frequencies for communications between units in the field and their dispatch centers. One frequency is used by base stations, located at electronic sites, most of which are placed on mountain peaks or other high positions. Cars, or mobile units, use a second frequency to talk with these base stations. On the list below the base frequency is shown as the "frequency" and the mobile frequency is shown as "input." It is important to realize that base stations transmit from higher elevations and at much greater power than mobile units do. For this reason the base frequency can be heard over long distances, while the lower powered ground level mobile units can only be received if they are close by. The dispatch centers use one or more electronic sites to communicate with mobile units. Remember that high locations are ideal for radio reception as they can "see" more territory than ground level sites. This is why the dispatcher can receive most of the mobile traffic, while the scanner listener cannot. Electronic sites are linked via microwave or 72 MHz frequencies and the dispatcher's console is controlled by a type of computer that chooses the best signal to send to the dispatcher if more than one site is receiving a mobile unit's signal at the same time. This computer is called a voter, as the selection among multiple sites is "voted" for the best signal. When transmitting to a mobile unit the dispatcher can choose the electronic site they want to use, and normally choose the same site the voter chose when replying to a mobile unit. This is why you may hear the base frequency come in well at times when a nearby site is being used and not so well when another, more distant site is being used. When units want to communicate directly with each other, commonly referred to as "direct" or "car to car", they both switch their radios to another channel where the radio is both receiving and transmitting on the base frequency. One disadvantage to this is the cars can have the same experience that scanner listeners have, which is that they cannot hear other mobile units that are located some distance away.

In some locations within the state, mostly in urban areas, and mostly in southern California, the mobile frequency is patched to the base frequency on the most often used electronic site within a dispatch area. Cars are now able to hear each other from longer distances that they could before. This works the best in dispatch areas that are small and mostly urban as in these areas most mobile units can receive the same electronic site. In rural areas the dispatch area can be quite large with as many as 6-12 sites and mobile units may only be in range of one of those sites. Since the advantage of having the other mobile units hear each other is lost, the mobile traffic is not transmitted over the base frequency in rural areas.

That should explain it somewhat..

San Diego office should be on 39.4000 with input on 42.6600

[dasmi]

Yep. Lots of traffic on 39.4. 42.66 is quieter, cause I'm rarely near a CHP cruiser that's transmitting.

[proudamerican831]

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