[Elecraft] KPA-1500 failed!

[Paul Baldock]

It sounds like one of the output devices have failed. Half power out 
is usually the indicator. A number here have reported this happening. 
It would be nice to know why this problem is occurring and if 
Elecraft are working on a fix.

- Paul

At 07:10 AM 2/16/2019, rocketnj at gmail.com wrote:
>I talked to Peter on the phone. He has no bias current when amp is 
>transmitting with no power applied (key on SSB without talking. He 
>is reading 54 volts and has tried power cycling amp from power 
>supply switch and reseated all cables. Definitely BAD distortion on 
>SSB (we are close enough to hear each other). Looks like one RF 
>device let loose and it is dragging down the bias voltage. That is my guess.
>
>Dave wo2x
>
>
>-----Original Message-----
>From: elecraft-bounces at mailman.qth.net 
><elecraft-bounces at mailman.qth.net> On Behalf Of Wes
>Sent: Saturday, February 16, 2019 9:49 AM
>To: elecraft at mailman.qth.net
>Subject: Re: [Elecraft] KPA-1500 failed!
>
>I think a two-tone test is the best evaluation tool..  The generator 
>is built into the K3 if you have another receiver that you can use 
>to listen to the amp output.  I use an SDR-IQ which is a very nice 
>tool for this but any other SDR would do.
>
>Sorry for your pain.
>
>Wes  N7WS
>
>On 2/16/2019 7:28 AM, lists at w2irt.net wrote:
> > I was operating in the ARRL-CW contest this morning and on 20m, with a
> > 1.2:1 SWR on the Yagi, all of a sudden I saw my power drop to about
> > 450-500W with about 40W in. Worked a few stations but not as easily as
> > when I turned everything on this morning. Switched over to phone 
> and made a few contacts.
> > Audio is fine barefoot with 100W out of the K3s-which suffered blown
> > finals itself during CQWW SSB last fall, but with the amp in I got
> > reports that my audio was badly distorted.
> >
> > Before I send it in, is there anything I should look at or any
> > diagnostics I can easily perform? For the cost of this, I'd have
> > thought protection would have kicked in to prevent anything untoward
> > from happening. I'm in complete disbelief, to be honest.
> >
> > ---------------------------------------------
> > 73 and Good DX
> > Peter, W2IRT
> >
>
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:Elecraft at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html 
>Message delivered to rocketnj at gmail.com
>
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:Elecraft at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html
>Message delivered to paul at paulbaldock.com