Follow-up... Today I did further testing and was quite surprised that I no longer had any addtional tones on my cw note and there was no longer any 60-cycle hum in the background of my signal when I listened in AM mode with my Kenwood receiver.
What changed? The only change made was to connect my computer to my local network directly rather than go through a wireless Buffalo Air Station. Hmmm... its late now, but perhaps I will go back to my prior setup and see if that was somehow the cause. Anyway, I'm back on the air and having fun! Craig, AE7I On Nov 10, 2007 5:28 PM, Craig Sande <[EMAIL PROTECTED]> wrote: > I didn't notice any change when I toggled the 'SR' button and it was > present to varying degrees from 60M through 10M. When I put my Kenwood > receiver in AM mode, I could hear a 60 Hz signal on the carrier, so I think > you may be correct about some form of ground loop. > > I disconnected everything from the back of the Flex-5000a except for the > firewire connection to the computer (which by the way was not grounded > initially), the ground connection, and the coaxial cable ouput to the dummy > load -- the spurious tones and am 60 cycle noise persisted. I DID NOT hear > these extra tones in the monitor output of the Flex-5000A while sending, > which argues against the software creating them. > I hooked up a ground connection to the computer, but it didn't change > things. I even powered the Flex-5000 from a battery and noted no change! > At this point, the only connections to my Flex-5000 are: firewire, coax to > dummy load, and power from battery. > > I'm stumped! > > Craig, AE7I > > > On Nov 10, 2007 4:22 PM, Jeff Anderson <[EMAIL PROTECTED]> wrote: > > > One possiblity could be spurious tones caused by mixing with DDS spurs - > > if > > you turn off Spur Reduction (the 'SR' button), do the extraneous tones > > change frequency or disappear? Do they change as xmit frequency > > changes? > > > > Also, if you can listen to the line-out audio, do you hear multi-tones > > there > > (but this may not be possible with the 5000A)? If so, that would imply > > that > > the spurious frequencies might be generated by software. > > > > Another possiblity might be a ground-loop, and you're hearing 120 & 300 > > Hz > > harmonics of 60 cycles. But I don't know how you'd get ground-loops > > with > > the 5000A (although it's certainly possible with the 1000). > > > > Someone who's more familiar with the 5000A and/or the software might > > have a > > better idea as to what's going on... > > > > - Jeff, K6JCA > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20071111/4a48c2d9/attachment.html _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
