If memory serves, Steve's mod to the Corsair II sidetone has one drawback:
it is a slower starting oscillator and therefore might not be very good for
QRQ.
73, Mike N4NT
----- Original Message -----
From: "Chester" <calderman@cox.net>
To: <tentec@contesting.com>
Sent: Friday, February 07, 2003 5:17 PM
Subject: RE: [TenTec] playing with the Corsair II
> Hi Irv,
>
> Good to hear from ya.
>
> Irv, there is two things you can do to that sidetone (square
> wave) generator in the CII. Since I had a spare Ten Tec audio filter
> from an old Triton xcvr (think it's a model 285), I just removed R90
> (47k) between the center arm of the S.T. LEVEL pot and the input to U5,
> the audio amp (in my schematic). I ran a wire from the resistor hole
> from the pot arm to the input of the filter and from the output of the
> filter, I ran a second wire to the resistor hole going to the input of
> the audio amp.
>
> I then 'jury-rigged' a mechanical means of physically mounting
> the audio filter board just about the CII's IF board and I connected +12
> and ground between the filter board and the IF board. (Of course you
> could use any audio filter you have available to run that square wave
> through to drastically improve the sidetone.) The old Triton board was
> good enough because if I recall correct, it had three audio bandwidth's
> to select from.
>
> The second mod you could try, and it's a much more professional
> approach, is a circuit that Steve, N4LQ came up with to replace the
> entire square wave sidetone generator. It's not complicated and you can
> see his schematic at:
>
> http://www.albany.net/~bg/Mods/sidetone.htm
>
> I also just acquired another Corsair II (think this is about my
> sixth CII!!), so I'm soon going to have to make the mod again if I
> decide to keep this CII. Let me know which mod you make Irv.
>
> 73,
>
> Tom/W4BQF
>
> Chester Alderman
> calderman@cox.net
>
> -----Original Message-----
> From: tentec-bounces@contesting.com
> [mailto:tentec-bounces@contesting.com] On Behalf Of Irvin Weinman
> Sent: Friday, February 07, 2003 10:57 AM
> To: tentec@contesting.com
> Subject: Re: [TenTec] playing with the Corsair II
>
> Tom: I am acquiring another Corsair II. I remember years ago you had
> given
> out the tech data to CFO types, for an audio filter mod to tame the
> annoying
> sidetone. Do you still have that information around? Irv W7GX.
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