The problem is solved. I thought I have to share with others what worked best or us. This solution came from Gary N7IR.
Try a few sheets of thin low carbon steel (in US called mild steel) insulated from each other by sheets of printer paper. Put this sandwich in between and parallel to the K3 and the rotator controller. That should knock it down by many 10's of dB if it is magnetic coupling. Make sure that the sheets are as long as the case of K3 and twice as tall. Also make sure the sheets don't touch either case. I've used this technique many times in my professional life and it works every time. Thank you Gary and thanks to all for alternative suggestions 73, Igor UA9CDC > > > My friend, K3 user is getting ready for CQWW SSB. In his > > installation the > > rotator control box that has pretty large transformer > > inside. The box is > > only few inches away from one of the two K3s and cannot > > be moved. He has > > discovered that magnetic field created by this transformer > > interacts with > > the AF transformer (Line in) in K3. The indused 50Hz noise > > is only 20db down > > from the audio signal. The noise is gone when line in is > > switched off in the > > menu but that leaves him without voice keyer which is > > tough to be deprived > > of in 48 hours SSB contest. Has anybody found a solution > > yet. He now thinks > > of taking the transformers out of the radio an bypassing > > them. He thinks > > that the problem roots to the fact that the K3 cabinet is > > made of aluminum. > > > > 73, Igor UA9CDC ______________________________________________________________ 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
