Bill, One possibility is that this rogue signal's frequency is not actually at 28.002 MHz, but at some other frequency which coincides with one of the K3 receiver's spurious responses when the K3 is tuned to 28.002 MHz. An example of one spurious response is the so-called image, which in the case of a K3 receiver tuned to 28.002 MHz would be at 44.432 MHz. Typical Superhets have many other spurious responses above, below and sometimes in the band being tuned.
Because you also hear this signal at 28.002 MHz when using another battery powered rig, at first glance my thought that the signal is not at 28.002 MHz would seem to be nonsense because the frequency used in the IF of your battery powered rig and the K3 are probably not the same, therefore the spurious response pattern in terms of frequencies of the two receivers would not be the same. But there is the possibility that some responses might in part cover the same frequencies. If I can be of any help, please contact me off-list. 73, Geoff GM4ESD Bill Hammond wrote on Saturday, October 23, 2010 at 18:40 + 0100: > It has been there for years, but isn't really a problem until someone > happens to be on that frequency and you want to talk to them. Like this > morning when FO8RZ was working up 1 from 28.002 and with the receiver set > on 28.003 I had the pleasure of listening to this repetitive tone until I > worked him :) > > So what the heck is it?? Obviously local, it is always there and never > misses a beat. I have pulled the big switch and listening with a battery > powered rig, it is still there. I assume some consumer product uses 10 > meters for some unknown purpose...ever encounter this Elecrafters? ______________________________________________________________ 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