Did you try running your monitor receiver on battery? 73 - Mike WA8BXN
-------Original Message------- From: Sam Morgan Date: 5/16/2010 8:03:33 PM To: Tom W8JI Cc: [email protected] Subject: Re: [Elecraft] AC hum on tune Well at this point I have: Gone on battery power Nothing is hooked up to the K3 Except the 12v power lines from the battery All reports of a hum on my tune signal Have come from stations 1/2 mile to 3 miles away My output power was varied from 1w to 100w Only difference was the hum was louder with more power One station 75.5 miles away did not hear the hum however The 80m band was QRN with storms and local noise at the rx station Clues?: Hum is louder on 80m than on 17m Nothing different if I go to battery or on ac/dc power supplies At this point I think for my next try (since I have been using it on SSB only so far) I will get on cw and see if I can get any R5 S9 T(1-6) reports If I don't I will quit freaking out and be satisfied for now. If that is successful I will start adding things back to the rig Ground, serial cable, line out, (external) tuner, IF output cable, Amp and keying line to amp, ground to amp, coax switch, Ground to coax switch, other antennas to coax switch, etc etc etc..... Hmmmmm lots of *stuff* involved when you get back to that point Hopefully somewhere along the way, Something will show it's self as the culprit Thanks to all who have offered suggestions on and off list. -- GB & 73 K5OAI Sam Morgan On 5/16/2010 3:03 PM, Tom W8JI wrote: > It is common for me to hear hum or buzz on local receivers very near a > transmitter. Even on perfectly clean transmitters unless I use a line > tap to sample signal all sorts of stuff mixes in. I've never really > looked into why. My guess would be it is some nasty multipath being > modulated by something. Just a guess. > > I'm not saying you don't have hum, but just cautioning you to be careful > when listening on a local receiver near a transmitter. I can replicate > hum on my shop receivers even with a very clean transmitter on the bench. > > That aside, did you try disconnecting everything except the K3 antenna > and power supply? > > Switching supplies do not normally cause 60 or 120 Hz problems. > > 73 Tom > ______________________________________________________________ ______________________________________________________________ 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
