Your OCF dipole will have common mode currents on the coax because it is not balanced. So yes, regardless of low SWR you have RF in the shack (unless you are shunting the currents to ground with a good RF ground and some common mode chokes) and it sounds like this stray RF is finding a path through the FLEX-3000 into the computer; probably via the Firewire cable. Ground the PC to the radio hardware and the amp then liberally use ferrite beads on both ends of the Firewire cable.
-Tim -----Original Message----- From: flexradio-boun...@flex-radio.biz [mailto:flexradio-boun...@flex-radio.biz] On Behalf Of Gary Robertson Sent: Friday, February 18, 2011 2:03 PM To: flexradio@flex-radio.biz Subject: [Flexradio] Unusual Behavior on 12 Meters I have a Flex-3000, using a new computer (windows7) supplied by Neal. I operate with an off-center fed dipole up at 40'. This morning while operating USB on 12 meters, I encountered a problem that I have not seen before. While in the middle of a normal QSO at 24.950, I suddenly got an error message up on the screen telling me that I was operating out-of-band. The radio's VFO changed to 65.000 Mhz and the band selector changed to GEN. I could no longer transmit. I was running about 600 watts out of a Tokyo Hy-Power amp at the time with an SWR of less that 1.3 to 1. This out-of-band error occurred on several occasions, but only on 12 meters. When I changed to barefoot, I no longer encountered the problem, which makes me wonder if it is RF related. I have never seen this error occur in the past on any band, with or without the amp running power. Any suggestions would be appreciated. Gary Robertson W5SAT groberts...@austin.rr.com _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/ _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/