Joe, You might check to see if the amplitude of the hum changes as you alter the position of the microphone. If so, the magnetic field of a transformer from another piece of equipment in the shack (such as a linear power supply) may be coupling into your microphone.
73, Dale - WA8SRA On Sun, Dec 2, 2018 at 4:19 PM Joe Rogers <jerogers...@hotmail.com> wrote: > I normally operate CW but the other day and have not been SSB for a few > weeks to a month. Yesterday, I was getting ready to operate SSB and I > noted a hum through the monitor when I key the transmitter. By way of > background, K3 is 2012 vintage and I assembled the kit. No problems with > until this one. I have found several similar threads mentioning a hum on > SSB transmit but of the mentioned solutions worked to solve my problem. > > I have Heil Pro set IC and Heil Gold Elite. The problem seems much more > pronounced with Proset IC. > > Whether it is connected to front panel (FP.H or RP.H Bias on) makes no > difference. If I used PTT or VOX it is there. Set Mic Gain at anything > above zero it starts. With higher mic gain and higher compression it is > worse. I have made some PSK contacts using the LIN IN input and seems to > work OK. > > It seemed like low frequency noise so I set the TX filters for 50 and 100 > Hz from 0 to -16. No change. > > Changed TX Gate from 0 to 10. No change. > > Disconnected everything from the K3 - RS232 cable, the antennas, keys, and > paddle. All except power supply and the Mic. No change. > > Mic+Lin ON or OFF no change. > > Curiously, if I put my hand on the rig, it seems to reduce the volume of > the hum. > > Recorded some audio with Proset on my PC and it seems clean - no noise > detectable. > > I wonder if any of you guys - all of you probably more technically savvy > than I - can come up with any ideas to solve this problem. > > Thanks in advance for any help you can give me. > > 73, > Joe > AJ1Y > ______________________________________________________________ > 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 > Message delivered to dmbor...@gmail.com > ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
