View Single Post
  #36   Report Post  
Old April 4th 05, 10:20 PM
Richard Harrison
 
Posts: n/a
Default

John Smith wrote:
"In other words, what set of formulas would give you length, conductor
spacing, hgamma capacitor value---?"

Arnold W.P. King was author of the Antennas section of "Transmission
Lines, Antennas, and Wave Guides", McGraw-Hill, 1945. Wing wrote
"Transmission Lines". Mimno wrote "Wave Guides".

On page 158, King wrote:
"---it is possible to modify the antenna itself in such a way that the
input impedance at its terminals is equal to the characteristic
impedance of the line. The usual arrangement, Hig. 28.3, is to attach
conductors at points CD along the antenna (which are not sufficiently
close to the near zone) and join these to the input terminals at AB. The
accurate calculation of the input impedance at AB of the modified
antenna as a function of the resistance CD and the lengths AC and BD has
not been accomplished."

I wouldn`t hold my breath waiting for accurate formulas, but you are
free to try it yourself. The gamma match is similar to the delta match
and must cope with some of the same problems. This may be a case for
experimentation.

Best regards, Richard Harrison, KB5WZI