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K3 - PA Temp Unstable

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paulb

K3 - PA Temp Unstable

Hi folks

K3 here owned for about 4 years.
Latest firmware.
Last couple of days at power up the PA Temp is unstable.
LCD flicks between 27 and 40 degs C.
TX and RX same reading.
Noticed the rear fans starting and stopping
Reloaded firmware no change.
Before lifting the hood anyone got a pointer what to
check ?

thanks

cheers

Paul b
zl1ajy

Mike Cox

Re: K3 - PA Temp Unstable

I'd like to see how this is resolved. I note the silence about it after
your post.

My early K3 (sub s/n 500) started doing this same thing intermittently
several months ago. The problem occasionally got bad enough that the rig
would cut back to low power mode and report the PA over temperature.
The problem would manifest itself upon power up after the radio had been
off overnight. Usually within and hour after power-up the PA temperature
report would stabilize and all was well. I pulled the PA board off and
did the gold pin replacement but this did not resolve the issue. A month
or so later, the temperature report stabilized. I have not yet pulled
the front panel to change out to gold pins in that area. As the radio
has not exhibited this behavior for the past month, I'm holding off
until I can tell that I've fixed it (or not) when I work on it. I love
repairing intermittant issues (not!). Anyway Paul, your problem is not
unique.

73,
Mike, AB9V

On 1/18/2014 3:41 PM, paulb wrote:

> Hi folks
>
> K3 here owned for about 4 years.
> Latest firmware.
> Last couple of days at power up the PA Temp is unstable.
> LCD flicks between 27 and 40 degs C.
> TX and RX same reading.
> Noticed the rear fans starting and stopping
> Reloaded firmware no change.
> Before lifting the hood anyone got a pointer what to
> check ?
>
>
> thanks
>
> cheers
>
> Paul b
> zl1ajy
>
>
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K3-PA-Temp-Unstable-tp7583051.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> 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

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wayne burdick

Re: K3 - PA Temp Unstable

Administrator

If you put a DMM (voltmeter) on the associated pin, you should see the voltage changing (a few mV, probably). You can easily get at these pins by taking the bottom covers (A and B) off the radio. Chances are that the old, non-gold pins on the front panel module are the cause.

73,
Wayne
N6KR

On Jan 20, 2014, at 7:16 AM, Mike Cox <[hidden email]> wrote:

> I'd like to see how this is resolved. I note the silence about it after your post.
>
> My early K3 (sub s/n 500) started doing this same thing intermittently several months ago. The problem occasionally got bad enough that the rig would cut back to low power mode and report the PA over temperature. The problem would manifest itself upon power up after the radio had been off overnight. Usually within and hour after power-up the PA temperature report would stabilize and all was well. I pulled the PA board off and did the gold pin replacement but this did not resolve the issue. A month or so later, the temperature report stabilized. I have not yet pulled the front panel to change out to gold pins in that area. As the radio has not exhibited this behavior for the past month, I'm holding off until I can tell that I've fixed it (or not) when I work on it. I love repairing intermittant issues (not!). Anyway Paul, your problem is not unique.
>
> 73,
> Mike, AB9V
>
> On 1/18/2014 3:41 PM, paulb wrote:
>> Hi folks
>>
>> K3 here owned for about 4 years.
>> Latest firmware.
>> Last couple of days at power up the PA Temp is unstable.
>> LCD flicks between 27 and 40 degs C.
>> TX and RX same reading.
>> Noticed the rear fans starting and stopping
>> Reloaded firmware no change.
>> Before lifting the hood anyone got a pointer what to
>> check ?
>>
>>
>> thanks
>>
>> cheers
>>
>> Paul b
>> zl1ajy
>>
>>
>>
>>
>>
>> --
>> View this message in context: http://elecraft.365791.n2.nabble.com/K3-PA-Temp-Unstable-tp7583051.html
>> Sent from the Elecraft mailing list archive at Nabble.com.
>> ______________________________________________________________
>> 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
>
> ______________________________________________________________
> 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

Mike Cox

Re: K3 - PA Temp Unstable

Thanks Wayne. I suspect that you are right. I'll collect the parts and
have them ready to go if the problem starts up again. Replacing header
pins like these is something I've done many times before so I anticipate
no problems with the repair. This radio has performed extremely well in
almost daily use for many years now. The fan speed/temperature
indication issue has been only a minor annoyance that I would have fixed
already if it weren't so intermittent.

73,
Mike

On 1/20/2014 19:06 PM, Wayne Burdick wrote:

> If you put a DMM (voltmeter) on the associated pin, you should see the voltage changing (a few mV, probably). You can easily get at these pins by taking the bottom covers (A and B) off the radio. Chances are that the old, non-gold pins on the front panel module are the cause.
>
> 73,
> Wayne
> N6KR
>
> On Jan 20, 2014, at 7:16 AM, Mike Cox <[hidden email]> wrote:
>
>> I'd like to see how this is resolved. I note the silence about it after your post.
>>
>> My early K3 (sub s/n 500) started doing this same thing intermittently several months ago. The problem occasionally got bad enough that the rig would cut back to low power mode and report the PA over temperature. The problem would manifest itself upon power up after the radio had been off overnight. Usually within and hour after power-up the PA temperature report would stabilize and all was well. I pulled the PA board off and did the gold pin replacement but this did not resolve the issue. A month or so later, the temperature report stabilized. I have not yet pulled the front panel to change out to gold pins in that area. As the radio has not exhibited this behavior for the past month, I'm holding off until I can tell that I've fixed it (or not) when I work on it. I love repairing intermittant issues (not!). Anyway Paul, your problem is not unique.
>>
>> 73,
>> Mike, AB9V
>>
>> On 1/18/2014 3:41 PM, paulb wrote:
>>> Hi folks
>>>
>>> K3 here owned for about 4 years.
>>> Latest firmware.
>>> Last couple of days at power up the PA Temp is unstable.
>>> LCD flicks between 27 and 40 degs C.
>>> TX and RX same reading.
>>> Noticed the rear fans starting and stopping
>>> Reloaded firmware no change.
>>> Before lifting the hood anyone got a pointer what to
>>> check ?
>>>
>>>
>>> thanks
>>>
>>> cheers
>>>
>>> Paul b
>>> zl1ajy
>>>
>>>
>>>
>>>
>>>
>>> --
>>> View this message in context: http://elecraft.365791.n2.nabble.com/K3-PA-Temp-Unstable-tp7583051.html
>>> Sent from the Elecraft mailing list archive at Nabble.com.
>>> ______________________________________________________________
>>> 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
>> ______________________________________________________________
>> 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

KENT TRIMBLE

Re: K3 - PA Temp Unstable

In reply to this post by wayne burdick

To validate Wayne's suggestion . . .

K3 serial numbers 008 and 021 both exhibited this problem within two
years of their 2007 manufacture, and both were cured with the gold-pin
replacement fix.

Neither have exhibited any further misbehavior in the intervening years.

73,

Kent Trimble, K9ZTV
Jefferson City, MO

On 1/20/2014 6:06 PM, Wayne Burdick wrote:

k6dgw

Re: K3 - PA Temp Unstable

Hmmm ... I don't have a PA Temp problem, but ...

Occasionally, a tap or hold on a switch will cause some other action
other than the desired one. During NAQP SSB, I was running KPA500 off
but with the KAT500 [KAT3 bypassed]. The 500 was having some problems
on 160, so I bypassed it and was going to try the KAT3. When I held the
ATU switch to turn it on, the AGC shut off. First time that's ever
happened. My hearing is very bad [disappeared one night on a mountain
on the other side of the planet in my 20's], but believe me, it was LOUD
in the phones. Took about an hour for my ears to recover.

Is this symptomatic of the "Gold Pins Problem?"

K3 S/N 642, I built it and basically, it works perfectly except for this
anomaly. Next time I decide to use the KAT3, I'll take the cans off first.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2014 Cal QSO Party 4-5 Oct 2014
- www.cqp.org

Anomaly [ah-NOM-ah-lee] n. A term used by NASA to indicate anything
from a burned out light bulb to the rocket landing pointy end down
outside Phoenix.

On 1/21/2014 9:36 AM, KENT TRIMBLE wrote:
> To validate Wayne's suggestion . . .
>
> K3 serial numbers 008 and 021 both exhibited this problem within two
> years of their 2007 manufacture, and both were cured with the gold-pin
> replacement fix.
>
> Neither have exhibited any further misbehavior in the intervening years.

______________________________________________________________
Elecraft mailing list
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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