Eric, Joe is correct.
The fact that the noise disappears when the antenna is disconnected AND when you shut down HRD indicates that your serial cable and/or the USB to serial adapter is radiating trash and that trash is being picked up by your antenna. Jim's suggestions are valid for that sort of condition - kill the bad stuff at the source, don't try to fix the symptoms (which is harder to do anyway). 73, Don W3FPR On 3/18/2011 9:10 PM, Elecraft K3 wrote: > Hi Joe; > > Thank you for the reply. As I mentioned to Jim , the noise completely > disappears on RX when the antenna is disconnected. This leads me to suspect > that the RFI is coming in on the antenna cable. Does that sound right? If > it was coming in on the USB to serial I would expect to still hear it when > the antenna was disconnected. > > 73 de Eric, KG6MZS > > > On Mar 18, 2011, at 3:22 PM, Joe Subich, W4TV wrote: > >> Replace the cable on your USB to serial interface and make sure >> your K3 has all of the "RFI" mods, particularly those involving >> the KIO3. >> >> What you are hearing is common mode noise from the USB cable that >> is being radiated into your antenna or being conducted via the >> RS-232 cable. >> >> 73, >> >> ... Joe, W4TV > ______________________________________________________________ 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
