On Mon, 21 Dec 2009 15:13:05 +0000, Ken Chandler wrote: >I've just done some tests with my k3 sn 3759 and have been told I have >a spurious signal 600Hz above my tx frequency. It was at first heard >with my amp on but I switched out the amp and ran the k3 with 100w and >my note was still there.
What transmit frequency? Did you have your internal speaker turned on? During the recent ARRL 10M contest, several NCCC members observed spurs on each others signals and reported it to Elecraft. I'm told that the cause is acoustic coupling between the speaker and the synthesizer board, and that the amplitude of the spur is greater on the higher bands. Elecraft is intimately aware of the issue, and is working on it at the highest levels. Obviously, the strength of the spur will be proportional to loudness of the speaker (on TX, the sidetone setting), and can be eliminated by turning off the speaker. BTW -- one reason these spurs are more obvious is that the K3 produces very little phase noise to mask them. In general, other rigs (including many that are much higher priced) produce a lot more trash. 73, Jim K9YC ______________________________________________________________ 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