Re: [Elecraft] k3 50Hz background noise
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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] k3 50Hz background noise
Make sure there is a ground wire on the rotator controller. That knocked the hum way down here. I had the same problem with my TS-850's, and there were no audio input transformers in that rig. Dave Hachadorian, K6LL Yuma, AZ - Original Message - From: Igor Sokolov ua9...@gmail.com Cc: Elecraft Elecraft@mailman.qth.net Sent: Wednesday, October 21, 2009 4:35 PM Subject: [Elecraft] k3 50Hz background noise 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ 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
