Online chatter about what rigs were used at WRTC and why got me to
pursuing something that's been bugging me for a long time -- the band
pollution produced by many of today's transmitters. K6XX tackled it in
talk to NCCC last fall, and over the weekend, when IOTA was slow (which
was a lot of the time in W6) moved on it.
For almost ten years, we've seen lots of analysis of receiver
measurements, but little attention to transmitter cleanliness. So on
Saturday, continuing on Sunday and today, I've been pulling data from
ARRL product reviews, putting it into a Quattro Pro spreadsheet, and
plotting a dozen or so rigs on the same graph. Two sets of data -- the
spectra 5 kHz either side of a CW signal, and phase noise out to 1 MHz,
pretty much tell the story.
All of the data is from ARRL -- my contribution is organizing it so that
we can better learn from it.
k9yc.com/TXNoise.pdf
This is rough, a work in progress. Comments appreciated.
The slides for K6XX's talk are at k9yc.com/publish.htm
73, Jim K9YC
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