K3 problem

[Jerry K8RA]

Well it looks like I have a problem.    There is an intermittent buzz on the
speaker audio.   When I turn on the radio it works perfectly.  But after a
few minutes a strong buzz overlays the audio.  It is sever.  You can hear
the stations under the buzz.   If I turn the radio off and immediately back
on, the buzz is still there.  However if I leave the radio off for 3 or 4
minutes and turn it on, it is fine for a few minutes and then the buzz pops
back on.   Also keying the radio on CW also seems to fire up the receiver
buzz.   Note that it is okay on a pair of headphones.  It is like it is
going into oscillation.  Everything else on the radio seems normal.

 

Any suggestions?    I suspect a component in the audio amplifier.   Does the
headphone jack take the audio signal before it hits the main audio amp?
I wish I had a set of circuit diagrams.

 

Jerry K8RA

 

 

 





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[Bill W4ZV]

Jerry K8RA wrote

I wish I had a set of circuit diagrams.

http://www.elecraft.com/manual/K3_Schematics_Jun_2010.pdf

[Cookie]

Jerry it sounds like a possible power supply problems.  Have you tried a different supply?

Sent from my iPhone

On Aug 16, 2010, at 11:28, "Jerry Pittenger" <[hidden email]> wrote:

> Well it looks like I have a problem.    There is an intermittent buzz on the
> speaker audio.   When I turn on the radio it works perfectly.  But after a
> few minutes a strong buzz overlays the audio.  It is sever.  You can hear
> the stations under the buzz.   If I turn the radio off and immediately back
> on, the buzz is still there.  However if I leave the radio off for 3 or 4
> minutes and turn it on, it is fine for a few minutes and then the buzz pops
> back on.   Also keying the radio on CW also seems to fire up the receiver
> buzz.   Note that it is okay on a pair of headphones.  It is like it is
> going into oscillation.  Everything else on the radio seems normal.
>
>
>
> Any suggestions?    I suspect a component in the audio amplifier.   Does the
> headphone jack take the audio signal before it hits the main audio amp?
> I wish I had a set of circuit diagrams.
>
>
>
> Jerry K8RA
>
>
>
>
>
>
>
>
>
>
>
> =======
> Email scanned by PC Tools - No viruses or spyware found.
> (Email Guard: 7.0.0.18, Virus/Spyware Database: 6.15660)
> http://www.pctools.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
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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