Tail Squelch

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Avidlistner
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Joined: 10 Dec 2010 12:19

Tail Squelch

Post by Avidlistner »

So I have a Whistler WS1098 and I am getting tail squelch on one of the channels. Quite annoying when volume is up. I’ve set squelch to max and programmed the CTCSS. I have and GRE psr 310 that I used as my 2nd, and that does not receive the tail squelch on that channel. Any thoughts?

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W1KNE
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Re: Tail Squelch

Post by W1KNE »

Yes, you're getting low level interference. If you took that scanner and went to the same frequency, without a PL, you'd hear the noise.

The reason why you hear the "tail" is there is a delay often in these scanners that mute after they stop receiving PL. This delay is intentional for two reasons.
The PL tone is an audible pilot tone. Meaning it's in the aural portion of the signal. Problem is, someone talking could mask it, or get close enough to it for a brief moment to mask it.
Second if the audio is suffering from multipath or picket-fencing, it can cause the PL to be briefly masked.
If the receiver was set to immediately scan upon losing PL, you'd miss half of the transmissions, so there is an inherent delay.

So when the primary transmission you're intending to hear, which has the PL ends, the scanner then passes through the interference until the PL detector releases the scanner.

You mention only one scanner is getting it but not others, that is in how the scanner functions, how selective it is to the noise.
It could also be an internally generated noise within the scanning receiver (what we used to call a "birdie").

Out of curiosity, what frequency?
Mike Fitzpatrick
Broadcast Engineer - RF Enthusiast - Municipal Fire Alarm Collector
Owner: Scan New England - NECRAT.US
Issues with Scan New England can be privately addressed to me.

Avidlistner
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Joined: 10 Dec 2010 12:19

Re: Tail Squelch

Post by Avidlistner »

155.070

Lynskey 85
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Re: Tail Squelch

Post by Lynskey 85 »

Are you getting that while trying to listen to Charlton PD? I have never tracked it down but have historically (10-15 years) had exactly what you are talking about while listening to Charlton PD on that frequency.
Greg Lynskey
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Communications Center Director - South Worcester County Communications Center

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W1KNE
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Re: Tail Squelch

Post by W1KNE »

155.0700 has been a birdie in GRE scanners for years. I had several that had that, until PL came about and I could squelch it.
Mike Fitzpatrick
Broadcast Engineer - RF Enthusiast - Municipal Fire Alarm Collector
Owner: Scan New England - NECRAT.US
Issues with Scan New England can be privately addressed to me.

Lynskey 85
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Joined: 29 Aug 2005 09:38
Location: Webster, MA

Re: Tail Squelch

Post by Lynskey 85 »

W1KNE wrote:
14 Sep 2020 16:06
155.0700 has been a birdie in GRE scanners for years. I had several that had that, until PL came about and I could squelch it.
I'm all uniden. And in fact Motorola radios sometimes tend to pick it up as well on 155.070
Greg Lynskey
W2GEL
Communications Center Director - South Worcester County Communications Center

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W1KNE
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Re: Tail Squelch

Post by W1KNE »

I'm familiar with it, as that has been Pittsfield, MA's PD frequency for ages too.

My Regency Z30 scanner couldn't receive it, because of the birdie.

When I got my first really good scanner, my Realistic PRO-2022, it was the first time I could hear them without it.
Mike Fitzpatrick
Broadcast Engineer - RF Enthusiast - Municipal Fire Alarm Collector
Owner: Scan New England - NECRAT.US
Issues with Scan New England can be privately addressed to me.

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