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KX1 Keying problem

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Sean Cavanaugh-4

KX1 Keying problem

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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Don Wilhelm-4

Re: KX1 Keying problem

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
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.733 / Virus Database: 271.1.1/2709 - Release Date: 02/25/10 02:34:00
>
>

______________________________________________________________
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Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Sean Cavanaugh-4

Re: KX1 Keying problem

Hi Don,

Thanks for the tips. It turned out to be a bad 1/8 in plug. The
insulation between tip and first ring is too small, so it doesn't fit
correctly. I probably tugged just a wee bit on the cord while testing
(apparently repeatedly... go figure). If I don't insert the plug in all
the way it works fine. If I use the KXPD1, it works fine.

I'll just change the plug and hit the air with my KX1 and my straight
key. Thanks and 73,

Sean - VA5LF

On 25/02/2010 3:12 PM, Don Wilhelm wrote:

> 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
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> ------------------------------------------------------------------------
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com Version: 9.0.733 / Virus Database:
>> 271.1.1/2709 - Release Date: 02/25/10 02:34:00
>>

Don Wilhelm-4

Re: KX1 Keying problem

Sean,

Good sleuthing. That is one reason I order only good name brand plugs
and jacks (Switchcraft is usually good).
I have bought junk from Radio shack that has given nothing but headaches
- other distributors that offer bargain prices have similar problems.

73,
Don W3FPR

Sean Cavanaugh wrote:

> Hi Don,
>
> Thanks for the tips. It turned out to be a bad 1/8 in plug. The
> insulation between tip and first ring is too small, so it doesn't fit
> correctly. I probably tugged just a wee bit on the cord while testing
> (apparently repeatedly... go figure). If I don't insert the plug in
> all the way it works fine. If I use the KXPD1, it works fine.
>
> I'll just change the plug and hit the air with my KX1 and my straight
> key. Thanks and 73,
>
>