[Elecraft] KX1 Keying problem

[Don Wilhelm]

Sean,

You say the KXPD1 has been working fine, so try a test.  Put the KXPD1 
back on, but leave the KX1 set for INP HND.
Use the dot side of the paddle only and 'key' it as you would with a 
hand key.  Does the KX1 do the same thing?
If it behaves OK, then look carefully at your hand key(s) and their 
cabling.  I would expect the resistance when the key is open to be very 
high, but if you find it is down in the thousands of ohms, that may 
cause the behavior you are seeing - clean the dust off the key (top and 
bottom) and see if that helps

If it mis-behaves with the KXPD1 during the test above, then the problem 
is in the KX1 - look at the soldering for the key jack,  C32 and C33, 
R16 and R17, U1 pins 24 and 25 and RP1 pins 5 and 6 - reflow the 
soldering for these components with a hot (750 deg F) iron and see if 
that helps.  Also be certain the U1 microprocessor chip is fully seated 
in its socket - the leads should be in the socket almost up to the 
shoulders.  It takes some amount of pressure to seat it - place both 
thumbs on the chip with the fingers beneath the board and apply 
pressure.  Many 'strange happenings' are cured by fully seating the 
microprocessor chip.

If all that fails to resolve the problem, about the only thing left is 
some strange behavior in the microprocessor itself, but this is the 
first time I have heard a report like yours, so that is very far down on 
the suspect list.

73,
Don W3FPR

Sean Cavanaugh wrote:
> Hi all,
>
> I have a KX1 that has worked just fine for me for the last 2 years or 
> so. I've been using the KXPD1 paddles without problem.
>
> I wanted to try working on some QRP contacts for the SKCC, so I plugged 
> in my straight key and set the input to "hnd". When I start sending, the 
> rig keys normally for about 20-30 seconds, then stays keyed for a random 
> amount of time, whether the key is closed or not. It will usually stay 
> keyed for between 10 and15 seconds, then unkey. If I close the key again 
> it will do the same.
>
> I can get it to stop by unplugging the key or waiting, but it will 
> continue to have this unkeying issue until I turn off the rig. It will 
> then work for 20-30 seconds and start all over again.
>
> I've tried a different key with the same result.
>
> Any ideas? I'd love to not have to use the big rig for SKCC contacts.
>
> Thanks and 73,
>
> Sean - VA5LF
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