[aprssig] Re: PL 100
wa2mct at mearle.com
Sun Jul 18 16:50:16 EDT 2004
PL is (or was?) a trademark of Motorla. "Private Line"
CTCSS is the generic term, Continous Tone Coded Squelch System
The actual tones used are an EIA evolved/ developed standard, set up so
that mechanical generators and decoders ("reeds", "vibrasponders", etc.)
would be less likely to falsely decode on the "wrong" tone.
At 16:35 07/18/2004 -0400, KC2MMi wrote:
>Rodney, I'm sure there must be some reason but I've never heard one given.
>"All" the manuals refer to PL tones and CTCSS tones as is they are different
>things. They refer to using a PL tone to get into receivers, and using a
>CTCSS as a selective squelch tone on your own radio, so you will only hear
>callers who are using that same tone. (i.e., "Privacy tones" in FRS radios.)
>Funny thing is, they are the same tones, AFAIK only the context is
>different. PL refers to using a tone when you transmit, CTCSS refers to
>requiring others to use it to open the squelch on your radio (once you've
>set that) but I suppose in order to confound newcomers and prevent them from
>joining the hobby, all the manuals deal with this as is they were different
>If there really is any difference, I'd sure be glad to learn it.
>aprssig mailing list
>aprssig at lists.tapr.org
) ) de WA2MCT Mark
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