[Elecraft] KPA500 Clicks

[Ken Chandler]

I have a very early KPA500, serial in low 200's.
I have a quiet outside shack and 
I've heard the Clicks since day 1.
I've always thought these were part of the amps normal operating noise environment.
If fact, I tend to notice more if I don't hear the clicks.
The description given - The passage of hot water through cold piping in the heating system at first switch-on in early mornings is spot on ..... A soothing click click click...
The click is an old friend ! and let's me know that's all's running well.

Ken.. G0ORH - K2, K3, P3, KAT500, KPA500

Sent from my iPad


> On 26 Jan 2014, at 23:25, Stewart <stewart at twinwood.me> wrote:
> 
> Heard it today for the first time. I find it quite soothing, but would like to 
> know more about it...
> 
> :-)
> 
> 73
> Stewart G3RXQ
>> On Sun, 26 Jan 2014 18:16:52 -0500, Sebastian, W4AS wrote:
>> I have noticed the same clicks with mine.  I run mostly meteor scatter on 6
> meters, which is somewhat similar to RTTY - long transmit times with a high 
> average output power.
>> 
>> After emailing Elecraft support on May 6th of last year concerning a failure
> of my KAT500 tuner (which apparently had nothing to do with the amp's noise), I 
> was told this was due to rapid expansion and contraction of the heat sink, and 
> even though it sounded like a relay, it was not necessarily coming from a relay. 
> What I found strange was that this noise didn't occur until the amp was several 
> months old.  I was offered the option to ship back the KPA500 in order to track 
> down the noise, and I did so.
>> 
>> After a few days, I received a telephone call from Elecraft with their
> analysis of the noise.  It was their belief that indeed the noise was coming 
> from rapid expansion/contraction of a metal piece in the amp; specifically what 
> is known as the Z-bracket.  At the time I was told that a few other customers 
> had experienced the same issue, although none were in the US and mine was the 
> first they had the opportunity to look at.  The Z-bracket was replaced with one 
> of a different metal composition, and I was told that several tests were run on 
> the amp and there were no other issues.  I received the amp back and did not 
> experience the clicking noise at first.
>> 
>> A few weeks later, using the amp in the same manner I had before, the clicking
> noise came back.  Once again I contacted Elecraft support.  Their response was 
> the same, the rapid expansion and contraction of the Z-bracket was what I was 
> hearing, and there were now several KPA500s which exhibited the same clicking 
> noise, but their conclusion was there was no damage caused by this.  In 
> addition, there were no faults in the fault log.
>> 
>> I wonder how many others have experienced the same clicking noise, and if the
> issue has been solved.  While I accept their analysis, I still find it strange 
> that if the amp is on, yet I haven't transmitted for several minutes, I will 
> still hear an occasional click.
>> 
>> 
>> 73 de Sebastian, W4AS
>> 
>> 
>>> On Jan 26, 2014, at 3:03 PM, Steve AI9T <steve at ai9t.com> wrote:
>>> 
>>> During a couple recent RTTY contest I have noticed that my KPA500 is making a
> noise. It kind of sounds like a relay clicking in and out. When I first noticed 
> it I thought it was a fan relay or something to do with the fan. But after 
> hearing this longer it seems to be related to the temp.  It clicks in an out 
> around the temps of 62C and 56C. It kind or reminds me of an old radiator 
> warming up and cooling off. I took the cover off yesterday and checked the nut 
> that holds the  transformer in place. I thought maybe that spring washer might 
> be a little loose but it wasn't.
>>> 
>>> Anyone else ever notice this? Hopefully it is not a serious problem.
>>> 
>>> Thanks
>>> 
>>> --
>>> 73
>>> 
>>> Steve AI9T
>> 
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