New Guy, PSR-310

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cdtek1969

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Hi guys just wanted to say Hi,
I am new here and new to trunk scanning/ talk groups.
I have been scanning conventional freq's for 25 yrs now,
I own the following scanners;

Pro-2046
BC-72 XLT
PSR-310

I guess I am a little confused on how the talk group thing works.

What is it exactly? - Dispatch / Car-Car ????

Control frequencies, talk group Id's, hex.......what is all this ???

Is there one example of how to program my PSR-310
with Las Vegas Metro, to get to understand it ??

Thanks from the newbie to this stuff...

Bill
 

DickH

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Here is my simple explanation about how Motorola trunking works. It may help you understand trunking.

T R U N K I N G

Motorola Trunking:
The object of trunking is to allow many users to share a relatively few frequencies.
A trunking system is controlled by a computer. Information (data) is exchanged between the system radios and the computer on a control channel, sometimes called a data channel. It sounds like a strong buzz.
A large system can have up to 28 freqs., 4 of which may be used as control channels. The control channel may be changed once a day or as often as the programmer decides. Some scanners need only the control channels to track an entire system. Just put in the 4 Control Channels.

Each group of users (Fire, Police, etc.) is assigned TALK GROUPS. In a Motorola Type II system, the most common type, TGs are usually in 32 number steps starting with 16 and going up to 65536; 16, 48, 80 --- 4656, 4688, 4720 --- 28944, 28976, etc. System radios can have more than 100 TGs programmed into them.

After all the freqs. have been entered and it is "trunking", the Banks become SCAN LISTS where you enter the Talk Groups you want to hear.
Use the Talk Group numbers in the DEC column, not in the HEX column.

When a user pushes the talk button on his radio, data is sent to the computer. The computer chooses an unused freq. and sends that data to all the radios using the TG of the originating unit. This all happens in a fraction of a second and it happens EVERY TIME a radio is used.

EXAMPLE:
Fire Dispatch calling Engine 4 (TG 4528 on 856.7125)
Engine 4 answering Dispatch (TG 4528 on 852.2625)
Respond to 73 Elm Street (TG 4528 on 855.9625)
Engine 4 responding (TG 4528 on 851.6375)

If you have entered TG 4528 into your scanner, it will decode the control channel data and change your scanner freqs. to follow the conversation on TG 4528.

This should get you started, but you should read the manual carefully. You may need to read it several times.

EDACS and LTR systems use the same principles, but they can not do Control Channel Only trunking, the TG numbering is different and the frequencies must be entered into specified channels in the scanner.
 

DickH

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To avoid any confusion, my writeup is for the older scanners with banks, etc. but the basic trunking concept is correct.
Your PSR-310 uses a new type of programming. Page 30 of your manual explains how to input a Motorola type system.
An anomaly in the Clark county system is they identify 6 control channels (red in the database). I have always understood Motorola systems used only 4 control channel freqs.,
so you had better enter all 6 for control channel only trunking.
 

cdtek1969

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Las Vegas, NV

DickH

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Thank you I will study this info tonight.

Where do you find these control channels

and talk group Id's?

I have seen 20-30 freq's listed at the top of a page
then talk groups listed below, broke down by fire-police
city, and so on... am I on the right track here.?

The red freqs I enter, not the others ?

This is the page I found

Clark County - Southern Nevada Area Communications Council (SNACC) Trunking System, Clark County, Nevada - Scanner Frequencies

Bill
That's it. Enter the 6 control channel freqs (RED) for Site 001, the Simulcast system. Your scanner will decode the data stream and you will hear everything.
There are two trunking modes, SCAN and SEARCH.
SEARCH mode lets you hear ALL active talk groups.
SCAN mode lets you hear ONLY the talk groups you have entered. So you need to go through the lists and choose which TGs you want to listen to, then enter them.
 

Junior08

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Check the wiki section of this website, there's some links to further explain trunking.
 

cdtek1969

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Ok

Ok almost there,
got control freqs in,, getting stuff mostly weak sounding,

need to enter talkgroup id's now. cross my fingers, i may have it down.
 

cdtek1969

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Yep, got it down.

.Got some clear transmisions

...Some talkgroup Ids come up active, but no audio,... others are weak sounding.
 

W2PMX

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Fayetteville NC
The scanner is listening to the same transmitters, regardless of the talkgroup you're hearing. So it could be certain people, or groups of people, talking differently. (A school bus driver will usually use the radio differently than a police officer will, for example.)

As far as no audio, that could be someone kerchunking (pressing the mic button just to hear the repeater come up), or someone pressing the button, then realizing that he has nothing to say. Or the equivalent of pocket dialing - someone dropping the mic on the seat (more common in a car with a front bench seat) and then sitting on it.

BTW, frequencies are more "hardware" and talkgroups are more "software". The scanner listens on a particular frequency. (It "idles" on the current control frequency. When there's a transmission, the control frequency just tells the scanner which talk frequency to go to in order to hear the transmission.) The talkgroup is the "channel" - a particular police or fire group, etc. A trunking scanner can be told to follow a talkgroup, so whichever talk frequency the radio system assigns the talkgroup for that transmission, or series of transmissions, the scanner follows it.

(The basic idea is that if the county usually has no more than 5 transmissions going on at once, but it has 20 "departments" using radios, with trunking it only needs 5 transmitters, but with a conventional system it would need 20 transmitters.)
 

eagleswings01

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Jul 27, 2011
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I just started programming in talk groups on my 310 a couple of weeks ago, and although it takes some getting used to, it definitely opens up more scanning possibilities.
 

eagleswings01

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I wish I could help you a little more - I'm still trying to understand the trunking thing myself. If it helps any, mine are very sporadic right now with poor audio. I'm wondering if an antenna upgrade will help.
 

cdtek1969

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Las Vegas, NV
I just ordered a secondary "dipole style antenna" for my window, just waiting on delivery. I had a major improvment 15 years ago with one, so hope it helps now.
 
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