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Old September 24th 03, 04:36 PM
Bill VanAlstyne
 
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"Mark Keith" wrote in message
om...

...As far as the gamma being a poor device that should not be
used, thats hogwash. 1000's have used those things with good results.


Here's a couple questions about gamma match construction:

1) Commercial gamma matches typically employ a gamma rod and integral
coaxial capacitor, constructed of two coaxially mating pieces of tubing/rod
separated by a piece of dielectric tubing. Do you know of any reference that
gives a formula for computing the capacitance of such a coaxial capacitor?

2) Antenna modeling programs like YO by K6STI require a specification for
the diameter of the gamma rod. But due to the coaxial capacitor
construction, I'm not sure what diameter is actually being called for. Do
modeling programs typically assume a coaxial capacitor integral to the gamma
rod, or do they assume a molded capacitor between the feedpoint and a
monolithic gamma rod?

Bill / W5WVO