Locking out certain channels..yes or no

[twocats]

I'm listening to the Montgomery County MD system most of the time, and I noticed that several of the channels always have a roaring sound. Not squelch-adjustable. An example is 868.86250. My question is, can I lock this out, or is the trunking dependent on it? I'm sorry if I'm not explaining this too well.

 

[Gary335]

I assume your trunking. To my knowledge, you can lockout any channel you don't want to listen to while trunking. i don't know how Mont. Co. works, but in Balto. Co they have certain frequencies on which vehicle location and other such data transmissions happen, and therefore they only make noise. I always keep all the noisemaking channels locked out so that the scanner won't stop on anything other than voice signals. If your not trunking, those channels are control channels for the trunked system, and they can be locked out as well if your not trunking and don't want to hear them.

 

[twocats]

Yes, I'm trunking. I wasn't sure if locking the noisy ones out would affect the trunking. Thanks for the reply! All that noise really was driving me nuts.

 

[Gary335]

Yeah I know what you mean. I always make sure to lock out anything that's not voice.

 

[Sac916]

I'm listening to the Montgomery County MD system most of the time, and I noticed that several of the channels always have a roaring sound. Not squelch-adjustable. An example is 868.86250. My question is, can I lock this out, or is the trunking dependent on it? I'm sorry if I'm not explaining this too well.

If I'm correct, you are monitoring a Analog and Digital (APCO-25 Common Air Interface) radio system.

The freq you are talking about is a DATA channel, this operates like a modem for a computer. Without that signal, the radios do not work. Without that signal, your scanner can not trunk.

If you programmed your scanner correctly, and monitoring a trunked radio system - you should not hear those DATA channels.

BUT

If you do NOT have a DIGITAL scanner and try to monitor DIGITAL channels, you'll only hear static.

 

[troymail]

If you are really trunking, we shouldn't be talking about a frequency....

What kind of radio are you using?

What talk group(s) is this/are activity on (the digits, not the name)?

Is you are really trunking and have only programmed the trunking frequencies, your radio may stop on one or more talk groups that have data signals like MOSCAD which is data being sent to mobile data terminals or station printers, etc. The other possibility would be an encrypted channel. In either of these cases, locking out the TG in question while in trunking mode is the right thing to do.

Depending on the type of scanner, if you lock out an actual frequency, you could miss conversations. If the radio you are using has a "control-channel only" mode, then the only frequencies needed by the scanner are the control channel frequencies.

 

[twocats]

It's an RS Pro-96, and I'm using a pre-programmed file for the Montgomery County Motorola Type II system. (http://www.radioreference.com/modules.php?name=TRSDB&sid=2142) I'm thinking it may be data communications, like you said. I still seem to get all the conversations when I lock the channels out, but I want to make sure I'm not disrupting the process and missing calls. 868.86250 is an example. It's just noise, but it does the MO percentage scanning on the bottom line of text. I hope this makes sense...I'm reading all I can as fast as I can, but a lot to go.

 

[troymail]

OK - the Pro-96 has a control channel only mode so as long as you don't lock out the control channel(s) and the radio is set to control-channel only, everything will still work.

I think (from what you are saying) that you are actually locking out a TALK GROUP that contains a data signal -- you aren't locking out the frequency. It's just that TG is active on that frequency at that moment.

I see two MOSCAD TGs for Montgomery County:

49424 c11 A MOSCAD 49456 c13 A MOSCAD
So if you are in trunking mode, you are probably locking out talk group "49424" or talk group "49456" and not 868.86250 Mhz.

 

[Gary335]

Yes he's talking about TG's not freqs. I accidentally called them freqs, when I should have said TG's. Sorry for any confusion.

 

[troymail]

Yes he's talking about TG's not freqs. I accidentally called them freqs, when I should have said TG's. Sorry for any confusion.

No problem - his original and subsequent posts talked about a specific frequency....