John, my findings are the same as yours. I only have a single 4 element beam, mounted about 25 feet above the shack on the apex of the roof. The noise reduces significantly when the beam is pointing away from the shack. I hear the noise when the P3 is on and fully connected to the K3 and PC but I also hear it when the P3 is on with no connection to the K3 or PC, other than the dc feed from the K3.
73 to all Geoff G3UCK ----- Original Message ----- From: "John Lemay" <j...@carltonhouse.eclipse.co.uk> To: <j...@audiosystemsgroup.com> Cc: <elecraft@mailman.qth.net> Sent: Wednesday, March 23, 2011 8:18 PM Subject: Re: [Elecraft] [K3] Noise from P3 > I've spent a bit more time investigating this noise, following my initial > response to David. > > The noise sounds rather like a buzz saw. It is quite audible on the K3 > speaker, it is strong enough to move the S meter, and it's visible on the > P3. There is not just one frequency, but the noise is every 19kHz (approx) > across the band. > > The noise goes away if:- > > 1. I turn the P3 off > 2. I remove the 2m antenna > > The noise reduces if:- > > 1. I disconnect the BNC at the K3 IF Out connector. > > I already have chokes on the DC lead to the P3. > > I think at this stage I should also make it clear that I have a highly > sensitive 2m system with masthead preamplifier, and four eight element > yagis > which are at present quite close to ground level. > > Regards > > John G4ZTR ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
