Tom - You asked;
"Roy Lewallen made some common mode impedance measurements of various
scramble wound chokes.
Anyone know where he published the results?? I forgot."
The choke descriptions (diameters and lengths of coax to be wound for each
band) are in the ARRL Handbook for the past several years, as well as in
the last few editions of the Antenna Handbook. If you need the exact pages
I can look it up for you.
While not Roy's work, there are some excellent measurements of air core
coaxial cable chokes wound on large diameter forms, as well as scramble
wound chokes at;
http://www.berkshire.net/~robbins/technote/airbalun.html
I think that work originally appeared on this list. It is highly
recommended reading to any one who needs a 1:1 choke balun. Didn't these
used to be called pseudo-baluns?
I hope that this helps. - Duffey KK6MC/5
James R. Duffey <ji3m@maxwell.com> (505) 764-3143
Maxwell Technologies Inc. http://www.maxwell.com/
2501 Yale Blvd SE Suite 300
Albuquerque, NM 87106-4200
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