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

[Steve Ellington]

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
>
> --
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> Problems:                 owner-tentec@contesting.com
>
>


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