K3 Erratic RF Power Drop, comes back up by just tapping top of radio

[Dean44]

Thanks in advance for your help and ideas.

 

My K3 recently started exhibiting an occasional RF power drop. It drops from
100w to sometimes 50w or 30w or lower. Then by tapping the top of the radio
it goes back to full power.

 

The SWR is stable and normal during all of this, and I verified that the
main power supply is stable during the event.

 

It seems like it is sometimes brought on by routine heating and cooling.
Like when I am running RTTY off and on.

 

Any ideas would be greatly appreciated!

 

Dean

 

 

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[Don Wilhelm-4]

Dean,

A problem that comes and goes with tapping usually indicates a bad
connection somewhere.
Does it do the same thing when operated into a dummy load?  If it does,
then there is a definite problem with the K3, but if it operates
properly into a dummy load, you can first suspect something in the
antenna/feedline.
Yes, small vibrations in the K3 case can cause similar behavior if there
is a loose UHF connector on the K3. First step is to check the tightness
of the UHF connectors.  Finger-tight is not tight enough, give the
connectors a gentle tug with pliers after you get them finger-tight.

73,
Don W3FPR
On 4/19/2014 1:57 PM, Dean wrote:

> Thanks in advance for your help and ideas.
>
>  
>
> My K3 recently started exhibiting an occasional RF power drop. It drops from
> 100w to sometimes 50w or 30w or lower. Then by tapping the top of the radio
> it goes back to full power.
>
>  
>
> The SWR is stable and normal during all of this, and I verified that the
> main power supply is stable during the event.
>
>  
>
> It seems like it is sometimes brought on by routine heating and cooling.
> Like when I am running RTTY off and on.
>
>  
>
> Any ideas would be greatly appreciated!
>
>  
>
> Dean
>
>  
>
>  
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>

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