Unfortunately I don't have a working test bench right now to do any
engineering. If somebody wants to run with the idea below and do
the breadboarding and write up the article I'd be glad to edit it,
HTML-it, and post it.
Basically you leave the encoder running all the time (Virden, it that
what the orange wire you were referring to does?), and have two
resistors in series between the encoder output and the TX modulator
input. A FET goes from the center point to ground. You control the
FET with the RX COR so that the encoder audio is pinched off when
the RX squelch is closed.
You can also use an ordinary NPN transistor in a pinch.
You'll need Courier font for the diagram below.
encoder
output --\/\/\/--+---\/\/\/\/---- to TX modulator (usually
! the top of the dev pot (may
! need a DC blocking capacitor)
!
+--!
!<---\/\/\/---to controller output
+--! or COR output
!
gnd
Personally, I'd not use the raw COR output - I'd add a little delay
somewhere in the system so that a fluttery signal didn't flutter the
PL encoder on and off.... Maybe use and RC network, or set up a
logic output on the repeater controller with a 1/3 to 1/2 second delay
and control the FET with it, and have a 2 to 3 second carrier delay
(hang-in) timer on the repeater.
End of problem.
By the way, this trick has been around for 30 or so years - I first did it on
WA6EWS's Mocom 35 to allow the PL encoder to be enabled or disabled - Moto
had a T-filter using two resistors like the diagram above with a capacitor to
ground... I used the front panel "extender" switch to short out the cap and disable
the tone.
Mike WA6ILQ
At 01:16 PM 12/20/03 -0600, JOHN MACKEY <[EMAIL PROTECTED]> wrote:
Yes, that would be very good for a write up!
"Chuck Kelsey" <[EMAIL PROTECTED]> wrote:
> Why don't you write it up in some detail and submit to Kevin for
> posting on the Repeater-Builder web site?
>
> Chuck
> WB2EDV
>
>
> ----- Original Message -----
> From: "Virden Clark Beckman" <[EMAIL PROTECTED]>
> To: <Repeater-Builder@yahoogroups.com>
> Sent: Saturday, December 20, 2003 8:19 AM
> Subject: Re: [Repeater-Builder] TS-64
>
> > This is defeatable, I have described this several times - instead of
> > turning off the tone generator thereby activating the reverse burst just
> > use a hold low in between 2 15K resistors to pinch the pl output of the
> > ts64 module going towards the modulator. To use this you will have to
> > hold the orange wire low full time, and you will find the switching time
> > is faster than the reverse burst.
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