Lynn, Your problem parallels mine exactly. Although your Astron switching supply only powers the K3, the Astron internally jumpers its negative voltage terminal to the chassis and AC ground. If you don't want to rewire the K3's microphone connector, or jumper an intenral RF choke, as some have suggested on the List, then you'll need to take the cover off your Astron and remove the ground jumper from the negative terminal. I checked my 30Amp Astron (Model SS-30M), and the jumper is easily removed. It goes from the negative voltage terminal to a screw on the chassis.
I'll be interested in what the folks at Elecraft tell you about the audio distortion problem. I doubt that the filter change will affect it, though the 2.8 kHz filter is a very nice filter. 73, Jim W8ZR > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:elecraft- > [EMAIL PROTECTED] On Behalf Of Lynn Lamb, W4NL > Sent: Saturday, November 01, 2008 6:43 PM > To: Elecraft Reflector > Subject: [Elecraft] K3 Feedback > > The exchange here on the reflector is enjoyable and very much a good > source > of information. I have no answers for the feedback problem with the K3 > but > let me offer my situation. > > There is feedback in my audio using the NCS Switcher and I have discussed > it > with Doug of NCS. There is no feedback using 5 other rigs.. the Orion, > FT-950, K2, Omni VII, and TS-480. > > There is no feedback when using a mic directly in the front of the K3.. > works great. I've not tried the rear mic connection at all. > > The power supply has nothing hooked up to it but the K3. It's an Astron > 25 > amp switching supply. > > Many things I've tried.. the normal things mentioned here on the 'net'. > Nothing helped. > > Elecraft has my K3 now looking into this problem, calibrating and changing > the 2.7 filter with a 2.8. I noted the 2.7 was not an enclosed filter and > the 2.8 ...or the other 8 pole filters I installed are enclosed. I've ask > it be replaced with the 2.8. Will it help the feedback problem (?), I > don't > have a clue, but it can't hurt. > > I feel Elecraft will find the problem soon. Any group of folks who could > design and build a box of 8.5 lbs of this caliber can find and fix this > problem. No question. > > Thanks for all the ideas and may I say there IS comfort in numbers > relative > to this issue, hi. > > 73, lynn W4NL > > > www.SEDCO.Homestead.com > > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
