[Elecraft] KPA500 thermal clicks

[Bill Johnson]

I own(ed) both.  I operate SSB and not continuous modes.  No clicking, no fan issues.  My hearing is good, yes the fans operate.  My THP 2.5KFx had much louder fan noise while rag chewing than the KPA1500.  If you are operating in full cycle mode with these lighter weight amps you will have some compromises.  Portability/weight was my love for the Elecraft amps not to forget the seamless, and to me, near flawless operation.

73,
Bill
K9YEQ

-----Original Message-----
From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of john at kk9a.com
Sent: Thursday, July 19, 2018 6:30 AM
To: elecraft at mailman.qth.net
Cc: a.durbin at msn.com
Subject: Re: [Elecraft] KPA500 thermal clicks

Nice documentation. My KPA500 also makes this clicking noise so I would say that your amp is functioning normally. Apparently many people on this list do not find it objectionable. My KPA500 is just a backup / casual use amp but I would still send it in if there was a mod to fix this. I wonder if the KPA1500 also clicks?

Back to the vanity callsign net...

John KK9A


ANDY DURBIN K3WYC wrote:


I placed my Android phone on top of my KPA500 and made a recording while making a few cycles of FT8 TX/RX.  The audio files can be found here:

https://www.dropbox.com/sh/amfy3dz8pgl083n/AAAKi2GYripXyIDjiLpJ2hDwa?dl=0


One file is the raw recording.  The second has been processed in Audacity to amplify to 0 dB peak.  The file starts before the first TX. Next the hum of the transformer can be heard with FT8 modulation in the background
from TX moni.   As the recording progresses the changes in fan speed can
be heard.   The click are always well above the fan noise.

I used this recording to perform some spectral analysis of the clicks.  I took one sample at the click and another sample of the noise just before the click.  I then subtracted the noise from the click and I think I have a reasonable click signature to use as a baseline for evaluating any mechanical changes I make in an attempt to reduce the clicks.

Crank it up and enjoy, especially if you think it's normal.

73,
Andy k3wyc

______________________________________________________________
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 k9yeq at live.com