*****Use a Collins Coaxial Balun*****
This was orginally described in the Collins Radio book "Fundamentals of
SSB, (2nd edition, 1959). Additional articles appeared in Ham Radio
Magazine (February 1980, March 1980); CQ Magazine (November 1993); and
Radio Handbook by Bill Orr (21st Edition),
An adaptation of the Collins Balun principal using a ferrite core to give
greater bandwidth was described by Joe Reisert, W1JR, in Ham Radio
Magazine, September 1978.
Jerry Sevick, W2FMI described a 4:1 version of the "pure" Collins concept
balun (as an Unun) in his article in CQ Magazine, January 1993.
If built out of RG-400 Teflon coax, they will withstand 5Kw continuous;
RG-393 Teflon balun will withstand 25Kw PLUS continuous; RG-213 will
produce a balun more than capable of handling the legal amateur power limit
with a large margin. They are simple to make...two coax connectors, some
coax (16 feet for a balun covering 6MHz-30MHz), and a coax "T".
Speaking from over 40 years of experience using this "type" of balun in
both amateur applications at the legal power liimit and in commercial
applications at power levels in excess of 25Kw, NO FAILURE has ever been
recorded!
Dave, K1FK
Fort Kent, ME
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