confused

[firefighter45]

Ok the local sheriff dept uses the freq. 858.887, but i have also noticed that Cargill has been on this freq. also. Why is that, I thought that a channel was assigned to one thing and no one else could use it. Now i'm confused. Also, when the cops call into the county it shows up one channel 43 but when the dispatcher talks back it is on channel 56. I don't understand, am I a dumb ass for asking this kind of stuff?

 

[scanrrman]

County SO in my area dispatch on one freq. and mobile deputies call out on another. This is very common. Also, I'm sure they use tones so that the SO does not hear anything that Cargill is saying due to the tone keeping out any unwanted interference. If you know nothing about tones, there can be several agencies using the same freq. but all agencies will have a different tone keeping them apart. CTCSS/DCS are subaudible tone(CT) or digital(DC) that are transmitted that only radios with that specific tone programmed can only Rx other transmissions that have the exact same tone present. This is how they get away with it. Might help to elaborate on the agency and state of the specific system you are speaking of and the type of radio/scanner you are using.

 

[firefighter45]

Ok I see what you are saying. I'm learning slowley. But is there any way of locking out Cargill since they are annoying and most of the time wipe out the county. Its a RS Pro-2037 scanner, it has a lockout button on it but then that will lockout both of the parties so I think I may be at a dead end. There is a lot of stuff to learn about radios, it's gonna take me a while.

 

[K0ATC]

Ok I see what you are saying. I'm learning slowley. But is there any way of locking out Cargill since they are annoying and most of the time wipe out the county. Its a RS Pro-2037 scanner, it has a lockout button on it but then that will lockout both of the parties so I think I may be at a dead end. There is a lot of stuff to learn about radios, it's gonna take me a while.

If the other gentleman is correct about the tones, you would just need to turn on the tone squelch and enter the tone of the agency that you do want to hear, anyone on that same frequency not using that tone can not be heard. I do not know if your radios have this feature. If it is an 800mhz frequency, are you sure that it is not a trunked system? Even if your scanner is not able to trunk track, you would be able to monitor an analog frequency, and most likely would hear more then one specific user on it at any given moment. Make sure its not a trunked system prior to doing anything else, it is rare to have a group of users in that band without it being a trunked system. Here’s a quick and dirty explanation of a tones and tone squelch, and also a trunked system.

Scott

A toned frequency is when a sub-audible tone, or sound is added to the transmitted frequency. The receiving radio will keep the squelch closed even if it hears activity on that frequency, unless that activity is accompanied by the sub-audible tone it is programmed to listen for.

A trunked system is a group of frequencies that for example can be used by every facility in a county, they share all frequencies, but “to keep this simple” a computer tells the radio what frequency to use and when to use it. The radios are set up with talk groups rather then channels or frequencies to use. The users can only hear the people in their talk group, and their radios switch frequencies back and forth at the same time and they do not even notice. This allows many users of different agencies to use a limited number of frequencies without interfering with each other. So you can see if you are listening to one of the frequencies in a trunked system, you could hear many different users on the same frequency.

 

[W4KRR]

Ok the local sheriff dept uses the freq. 858.887, but i have also noticed that Cargill has been on this freq. also. Why is that, I thought that a channel was assigned to one thing and no one else could use it. Now i'm confused. Also, when the cops call into the county it shows up one channel 43 but when the dispatcher talks back it is on channel 56. I don't understand, am I a dumb ass for asking this kind of stuff?

It sounds like you have both repeater input and output frequencies programmed into your scanner.

If these are conventional channels, then using the PL tones would help. However I don't think the scanner you have supports PL tones.

It would help if you told us where you are located, and what agency you're trying to monitor. State, county, city, etc.

 

[boatbod]

Sounds rather like a trunked system to me. You can probably check by looking up who those frequencies are assigned to in your area (using RR query or FCC database) and then seeing if that callsign is part of a trunked system or not.

 

[freqhopping]

Your listening to one frequency of a trunked system.
Illinois Cooperative Association / ClearTalk - 800 MHz (Statewide) System
http://www.radioreference.com/modules.php?name=RR&sid=2711

 

[K0ATC]

If it is an 800mhz frequency, are you sure that it is not a trunked system? Even if your scanner is not able to trunk track, you would be able to monitor an analog frequency, and most likely would hear more then one specific user on it at any given moment. Make sure its not a trunked system prior to doing anything else, it is rare to have a group of users in that band without it being a trunked system.

Now that freqhopping has verified this, you do not really have any other options then to use a trunk tracking scanner. Seeing that you are from Illinois, do not waist your money on any trunk tracking scanner, you would be best to get a digital such as the BCD996T. I have lived in IL for 25 years, now in OK, but the whole state is going digital, amoung many other digital systems. This is especially true if you are near Chicago. If you need some help with this let us know.

Scott