Re. Experiment: how much PL tone deviation is required to reliably key repeaters?

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Re. Experiment: how much PL tone deviation is required to reliably key repeaters?

Ian Greenshields
In the UK, the requirements are fairly clearly defined as part of the
licence conditions for the repeater:

access:The repeater must not be carrier accessed directly from "cold" and
adequate immunity must be provided against access by speech or noise.
Initial access shall, as a minimum, be by a carrier modulated with a CTCSS
tone of the frequency stated on the Notice of Variation.
The CTCSS detector for this purpose, should respond to only that tone, when
it is present for less than 1 second at a deviation of 10% or less of the
appropriate maximum i.e. +/-500Hz for 25kHz units and +/-250Hz for 12.5kHz
units.
In addition, but optionally, access may be by a tone "burst" of 1750Hz plus
or minus 25Hz at a deviation of 50% or less. The acceptance time of the
tone between 200 and 400ms.
The repeater once accessed, must radiate the same CTCSS tone at nominal
level of 10% of maximum. I.e. +/-500Hz for 25kHz units and +/-250Hz for
12.5kHz unit.

73 Ian G4FSU
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Re: Re. Experiment: how much PL tone deviation is required to reliably key repeaters?

Phil Kane-2
On 9/8/2014 2:44 AM, Ian Greenshields wrote:

> The repeater once accessed, must radiate the same CTCSS tone at nominal
> level of 10% of maximum. I.e. ±500Hz for 25kHz units and ±250Hz for
> 12.5kHz unit.

Interesting that the UK requires transmitted tone as well as received
tone.  Although I support this when I can, it has not been all that
common on US repeaters.
-- --
73 de K2ASP - Phil Kane
Elecraft K2/100   s/n 5402

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon
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Re: Re. Experiment: how much PL tone deviation is required to reliably key repeaters?

Jim Brown-10
On Mon,9/8/2014 9:44 AM, Phil Kane wrote:
> Interesting that the UK requires transmitted tone as well as received
> tone.  Although I support this when I can, it has not been all that
> common on US repeaters.

It's pretty much standard where I have lived -- nearly all repeaters in
the Chicago area transmit PL, as well as here in Northern California
where I live now. Two major advantages. First, if propagation allows
your receiver to hear a distant repeater, activating receive PL in your
rig prevents it from bothering you. Second, receive PL allows your RX to
be muted when your PL is not present, so your RX doesn't unsquelch when
you drive through an area of loud noise.

73, Jim K9YC
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