[TenTec] Corsair II >> Obnoxious relay -----

[Avila, Edward]

My Corsair II K1 relay is very quiet, but a friend of mine sez his CII is
noisy to distraction! Good tips to send on to him, and maybe some day I'll
need to "quiet" mine down when it gets obnoxious too! 73....k6sdw

-----Original Message-----
From: Steve Ellington [mailto:N4LQ@iglou.com]
Sent: Friday, November 10, 2000 3:22 PM
To: KF6ZZ@aol.com; tentec@contesting.com
Subject: Re: [TenTec] Corsair II >> Obnxious relay -----



Easier yet. Cram a piece of cardboard between the relay's contacts. It works
and is easily reversable.

Steve
N4LQ
----- Original Message -----
From: <KF6ZZ@aol.com>
To: <tentec@contesting.com>
Sent: Friday, November 10, 2000 4:19 PM
Subject: [TenTec] Corsair II >> Obnxious relay -----


>
>  Gentlemen :
>
>   After two months as a CII owner, I finally decided to try my hand at CW
> operation; having heard such marvelous reports of the CII being the
consumate
> world class CW rig ....
>
>   So I plug in my trusty J-38 and start terrorizing the 40 meter novice
band
> ...
>
>   And am greeted with this miserable raccous clacking and clucking after
each
> line of code.
>
> It sounded like a dying chicken inside the radio ...
>
> Turns out that all the noise was coming from relay K1 on control board
80978.
>
> K1 is used for activating a linear amplifier.
>
> I am not running a linear.
> I am running QRP 5 watts.
> Relay K1 is not required for barefoot operation:
> " ... this relay does not control any of the internal functions of the
> transceiver..."
> ( a direct quote from page 2-3 of the Corsair II manual )
>
>   So I start investigating, and find that it is easy to silence K1 for
> barefoot operation.
>
>   All one has to do is disable the circuit
>  that activates the coil of relay K1.
>
>   From the 80978 Control board schematic ( page 3-32 of the CII manual )
it
> is obvious that transistor Q10 switches the K1 coil to ground to energize
the
> relay.
>
> Easiest way to disable this function is to short the base to emitter
junction
> of Q10.
> Now Q10 will never be activated.
> And the drive circuitry into Q10 will never be able to tell the
difference;
> and will not be compromised.
>
> Q10 is located on the corner of the circuit board about a half-inch inch
from
> K1.
>
> I used a miniature alligator clip, and clipped it across the base-emitter
> leads of Q10.
>
> Reverse modification is a obviously a simple matter.
>
> Now my Corsair II works like a dream.
> Velvet smooth QSK and PTT,
> nice and quiet like the Scout.
>
> I never did like noisy relays ...
>
> -Phil
> KF6ZZ
>
> --
> FAQ on WWW:               http://www.contesting.com/FAQ/tentec
> Submissions:              tentec@contesting.com
> Administrative requests:  tentec-REQUEST@contesting.com
> Problems:                 owner-tentec@contesting.com
>
>


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