Hi LF I think the issue is intermodulation products caused by over driving the the linear RF stages of the TX into distortion because when Jim reduces drive the sidebands petty well disappear at this
I think the issue is intermodulation products caused by over driving the the linear RF stages of the TX into distortion because when Jim reduces drive the sidebands petty well disappear at this range
Dear Rik, Pete, Jim, LF Group, I don't doubt that supply ripple to the PA could produce unwanted sidebands on a signal, but there are a couple of reasons why I don't think this is so in the case of G
Dear Jim, LF Group, FYI - Here is a spectrogram of G7NKS in WSPR recorded this evening, showing the sidebands at +/-50Hz and +/-150Hz - I couldn't see any other spectral components. Cheers, Jim Morit
Hi Pete The Rig only gets overly hot on powers over abt 20 watt output and 20%+ duty cycle (not to be unexpected given the operation at or beyond the limits of design). When I run it around 10 to 15
Hi Rik That's exactly what mine are. I think it's a mixture of stretching the Pa on the IC735 so its at the edge of its envelope (the radio equivalent of a stick shaker or stall horn on a plane!) and
OK Jim and LF Yes when you reduced power from 45w? down to 7w the side bands assuming they were still there but at the same relative level may possibly be unreadable by me. 45/7=6.4 times reduction 8
Hi all, the AM sidebands on my signal were in average 33dB down on the "real" signal, meaning that the sideband ERP was about 0.1mW. Having a look at the WSPRnet database showed sideband WSPR spots f
Hi Andy I suspect its my drifty IC735! Poor old girl! With best regards Jim --Original Message-- From: [email protected] [mailto:[email protected]] On Behalf Of Andy
Not sure if it is significant, or just tuning, but the log of G7NKS reports of me are about 40 - 50Hz low in frequency, and varying by a few Hz from hit-to-hit over the last few hours. Andy www.g4jnt
Jim, I lowered my antenna last night as gales up to 100km/h are predicted. Regarding CW: let me know when you are ready and I will look out for you. I worked G's with only few mW ERP in the past. 73,
Hello Jim, LF group, I have noticed "double receptions" of my WSPR signal from a number of stations. When it occurred the ghost signal was always 100Hz higher and was 33-36dB weaker. As the frequency
Hi Rik and LF In Jim's case he has two sidebands indicative of AM modulation and you are right they are about 30 odd dBs down on the carrier. Not too bad suppression by 1950's standards.... hee hee.
Dear Jim LF Group, Looking at the sidebands on the G7NKS WSPR signals, mains hum or other noise by itself is not a sufficient explanation of what is seen. Simply adding 50Hz, 150Hz, etc. noise into t
