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Question of Curiosity...

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btritch

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Can anyone out there tell me why on a motorola mentor pager that is programmed to a certain frequency, when that frequency recieves a transmission tone you can hear the double low/high pitched tone but on a scanner you cannot? Is it in the programming? Is there a way to program a scanner to recieve this? This has been in the back of my head for about two weeks and it's got be about to go crazy with curiosity.. Can anyone tell me why that is? Thanks!
 

drew6553

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I can hear the pageout tones just fine on my scanner sometimes even before my minitor 4 picks them up due to a bigger antenna
 

mrsvensven

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Is the scanner programmed with a PL? It is possible that the tones are not transmitted witha PL.

My scanner recieves tones just fine.
 

btritch

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I have one that is and one that isn't and they both have the same tones, That's what I thought the PL tone actually was was the pager program but I guess I was wrong. I thought it would have the two tone high/low pitch like my minitor does but it doesn't it's just one long tone....Apparently it wasn't the PL Tone like I thought..
 

mrsvensven

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btritch said:
I have one that is and one that isn't and they both have the same tones, That's what I thought the PL tone actually was was the pager program but I guess I was wrong. I thought it would have the two tone high/low pitch like my minitor does but it doesn't it's just one long tone....Apparently it wasn't the PL Tone like I thought..
PL==CTCSS
http://wiki.radioreference.com/index.php/CTCSS
The radio transmits a tone, which you can't hear (usually). The other radios listen for that specific tone, so they only hear the radios that are programmed with that tone. It reduces interference between two users of a frequency.

The tones that makes the minitor go off are used only to set off the pagers. It is something different. The PL tone is being transmitted whenever anyone is transmitting.
 
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btritch

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Ok, That cleared it up...That's what I wanted to know, I thought so, Dang! I wish I could get those on a scanner.. That's how I told what department was what. Now I'll have to memorize the other tones.. lol
 

ampulman

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mrsvensven said:
Is the scanner programmed with a PL? It is possible that the tones are not transmitted witha PL.

My scanner recieves tones just fine.
You are most likely right. When I received my 396T, I programmed in the local FD/EMS dispatch frequency, which gave alerting tones.

Later, I made some changes to the system and re-entered the frequency (with PL). Guess what-- no tones.

Just for fun, I entered it again without PL, but with CTCSS search on. First I would hear the tone (no PL). At the end of the tone, there is a 'chirp' and PL turns on.

I decided that the tones were too annoying, so I programmed the PL in permanently.

AM
 

CCHLLM

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On a great many systems, the PL encode is "stripped" from the carrier for the period that the paging tones are sent, then the PL encode resumes. This is because not all decoders are created equal and some can't distinguish that the PL isn't part of the paging tones. In other words, the pager fails to go off because its receive audio characteristics cause the decoder circuits to see the PL tone mixing with the paging tones, and it decides that the tones it's hearing aren't the correct tones. This is a bit of an oversimplified explanation, but the solution is to program the the system logic of the encoder system to signal the transmitter control logic to drop the transmit PL when the paging tone function is active. Izzat clear as mud?
 
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