How to elliminate squelch tails

[FP761]

Hello all. I searched the threads and could not find anything related to squelch tail ellimination. Has anyone developed a way to elliminate the receiver squelch tails from being broadcast over their feeds? I'm sure it's possible, but not sure how to do it. If I turn up the squelch control, I will lose the weaker signals.

What about re-broadcasting the receive audio using a seperate radio and transmitting DPL. Then, have another receiver with DPL enabled to receive the re-broadcast transmissions? Hmm, not sure, but I think it can be done.

 

[PeterGV]

I'm not sure if this will help, but...

The way "regular" two-way radios, like those used in public safety, accomplish this is on transmit they drop the PL/DPL first and then drop the carrier. Then, on receive, you program the radio to stop receiving when the PL/DPL tone is dropped. This usually eliminates the squelch tail entirely.

I'm not sure how the scanners treat loss of the tone when scanning.

Peter
K1PGV

 

[FP761]

Peter,

Thanks for the info. Unfortunately, Lancaster County Fire & EMS does not utilize a Coded Squelch, they instead use carrier squelch. This makes it difficult to elliminate squelch tails.

 

[PeterGV]

Interesting choice on behalf of that radio system's administrators. I bet the FF and EMS people get tired of hearing that squelch tail, too. And, just like you said, if they tighten the squelch up enough to eliminate most of it, they run the risk of losing reception in fringe areas.

Peter
K1PGV

 

[W2NJS]

Unless a TPL or DPL is transmitted you can't do much if anything to eliminate a squelch tail. Some older radios had independent squelch tail eliminators but the common practice today is to use a reverse burst system. You can actually see/hear a reverse burst if it's being used. The carrier drops, and then for a quarter or half a second a burst of carrier is transmitted, but you'll only find this on public service commercial radios, not on scanners, and not on any ham HT's or mobiles that I've ever encountered.

 

[GTR8000]

The carrier drops, and then for a quarter or half a second a burst of carrier is transmitted, but you'll only find this on public service commercial radios, not on scanners...

Reverse burst is all about the transmitter, not the receiver. If a scanner is programmed to receive with PL, and a reverse burst is transmitted, you (ideally) won't hear the squelch tail. Same goes for RX with ham gear, or any other receiver that is PL enabled. Naturally if the receiver is CSQ, you'll get a squelch tail regardless of what the transmitting radio is putting out.