No sooner do I make a post regarding the KPA500 hum issue (below) then I read a post from Eric (WA6HHQ) saying that the hum is normal for the design and not a problem. Thanks for the feedback Eric. Now that I know it normal I'll not worry that I did something wrong when I assembled the amp. ;-)
Frank - W6NEK ----- Original Message ----- From: "W6NEK" <[email protected]> To: <[email protected]> Sent: Wednesday, August 03, 2011 8:59 AM Subject: Re: [Elecraft] KPA 500 Hum >I confirm the exact same hum issue as Mike describes below. > (Front panel power switch is off and there is an intermittent acoustic hum > that can be heard) > I own KPA500 #236. It's not a problem so long as it's not doing any > damage. > Lets see what the folks at Elecraft come up with after their > investigation. > > Frank - W6NEK > > ----- Original Message ----- > From: "ai6ii" <[email protected]> > To: <[email protected]> > Sent: Monday, August 01, 2011 10:13 PM > Subject: Re: [Elecraft] KPA 500 Hum > > >>I too have noticed a hum emanating from the KPA500 (#26), but the >> circumstances are a bit strange. The hum comes sometimes when the KPA500 >> is >> off. By that I mean it is powered down (front panel power switch is >> off..no >> leds are lit), but not removed from the AC outlet. If I flip the rocker >> switch on the back of the rig, the hum disappears, which would make sense >> because no AC would be coming into the box, right? >> >> But if I leave the back rocker switch on and use only the push button >> switch >> on the front panel to turn the amp on and off, occasionally I hear a hum >> when it is 'off'. And I do mean only occasionally. I have noticed it only >> a >> few times and I have been using the amp almost daily for the last month >> and >> a half. When it has occurred, it has been eliminated by switching off the >> rocker switch in the back. >> >> It is not really a problem for me, but I thought it might be additional >> information for Wayne et al. >> >> ..mike AI6II > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1390 / Virus Database: 1518/3807 - Release Date: 08/03/11 > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
