Good morning gents...
I have RFI in the mike since using the Microkeyer II from Mikroham. Mainly on 20m and the lower bands when transmitting with about 700watts and above. My antenna is about 5meters above the shack on the roof of my house (2 el Ultrabeam), but the effect also can be observed on the lower bands where the vertical is about 12 meters away from the shack. ==> Direct RFI? I am using the front mike jack on my K3 and Microkeyer - I have put a capacitor across USB and connector ground in the Microkeyer as recommended by Microham. - All devices are grounded on common ground and same wall plug. - I have extra grounded my PCs ground with USB ground as the resistance was not good enough..its now 2 Ohms USB between USB and connector ground. Also recommendation by Microham. - Bought an extra shielded USB cable and put ferrite cords on. - Mic line is shielded and ferrite cords in every cable and line - Common mode chokes at the antenna feedpoint and also at the end of the coax going into the shack. - Pin 8 of the mike jack is not connected. See http://elecraft.365791.n2.nabble.com/K3-quot-RF-Feedback-quot-and-microHAM-MK2R-or-microKEYER-II-td1080853.html Microham is stating on their website that it has to do with the wiring of the K3 mike lines in the frontpanel.. I am really lost and helpful for any ideas. Is there an alternative to Microham? Thinking about going back to my old USB interface, but integration of Radio, Software and Ultrabeam is really nice We had a similar issue on our clubstation and could cure it with ferrites...on a YAESU rig. Any hint is appreciated..and thanks for quick feedback as usual. Already dropped a line to Elecraft support if they have some hints... I am glad the effect does not show on CW :-) Many thanks in advance. Best 73s Bernie DL5RDP ______________________________________________________________ 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 Message delivered to [email protected]
