Wanting to help in Grundy County / Morris

[Jake68111]

With the recent snow storms we've had the last couple of weeks, I have submitted a few new TGs on the Grundy County Public Safety system but on my last submission, Starcom21 messaged me the following:

"Lots of unknown PL tones in the county and new frequencies listed in the comments. Can you help verify any of these?"

I'm using a PSR-800 in Morris.

If someone could explain what a PL tone is and its correlation with a frequency is (how do I use my scanner with these?) and where I might find these "new frequencies" so that I can monitor them.

I'm listening all the time but never "search" for new freqs. I have found the new TGs on the G.C.P.S. system by adding and recording the wildcard, then I go back and carefully try to piece the tx's together.

Wanting to help out, just don't "fully" understand how to do so (PL Tones, these "new frequencies" etc.)

 

[cubn]

The PL tone is a sub audible tone that is transmitted so that receivers can filter out unwanted signals. For example if your local fire department uses 154.190 with no PL tone, they fire fighters (and dispatch) will hear any other agency using 154.190 within listening range. So if the county thirty miles away is on the same frequency, they may hear chatter on that frequency (especially the base radio) instead of just the local communications. But adding a PL will help them to only hear the local users.

For example, the U of I has many departments on 453.600. The ice arena uses PL 114.8. The residence halls use PL 173.8 on the same frequency. With the PL tones, the residence hall radios won't hear the ice arena people talking unless both departments decide to talk at the same time.

The PL tones are a good "fingerprint" to know what agency you are hearing. If you hear a distant signal and can read the PL tone, you have a much better chance to find out what agency it was you just heard.

More info:
DCS - The RadioReference Wiki
Continuous Tone-Coded Squelch System - The RadioReference Wiki

 

[Jake68111]

Thanks for breaking that down a little bit for me.

Now, with that being said, will my scanner (PSR-800) automatically display this PL Tone? Is that moderator asking that I submit the PL Tone that gets displayed, for those not in the R.R. database for Grundy County?

I guess I'm basically asking how I would use my scanner to help out in regards to these PL Tones. What do I need to do and what information can I provide?

Where might I find these "new frequencies" that were mentioned?

I'm not sure why I feel like a noob because I've been in the hobby for a while but I do want to help and I listen enough, I see no reason why I can't besides trying to understand whats being asked.

 

[cubn]

See pg 58 of the user manual. Any PL tone (or sometimes listed as CTCSS/DCS) updates you can submit would be great. Things like public works, school buses, businesses, etc. are often in the database but nobody has verified the tone yet so you can assist by submitting what you hear. I don't know how to do it in your particular scanner, but you can enter FCC licensed frequencies that aren't in the Radioreference database and report on the frequencies, tones, and usages of what you have heard, or use the search function on the scanner.