[ILHam] Antenna Modeling Program at MAC meeting April 4

MFGardner at aol.com MFGardner at aol.com
Wed Mar 29 23:25:31 EST 2006


The meeting of the Metro Amateur Radio Club on Tuesday, April 4, at 7:30 p.m. 
at the Lincolnwood Community Center, 6900 N. Lincoln Avenue (Lincoln Avenue 
at Morse Avenue), will feature MAC member Don Burman, KB9WBM, with a program on 
some computer-based antenna-modeling aids. Don was interested in building a 
simple wire antenna for portable use. He began by basing his antenna on the 
Norcal Doublet, a 44' non-resonant doublet fed by parallel feedline and is 
popular in the QRP community. Since Don's yet un-built/un-purchased dream rig is the 
Elecraft K1, he decided to "optimize" the Norcal Doublet for use with the K1. 
Don has done detailed research on the Extended Double Zepp upon which the 
Norcal Doublet is based. He'll be demonstrating how and why he's made some of the 
decisions he has using the EZNEC antenna modeling program, the HAMCALC 
collection of programs and the Transmission Line Details program.
    He'll also refer interested members to the fine sites by L. B. Cebik, 
W4RNL, and Tom Rauch, W8JI. While Cebik presents the 44' Doublet as a 40M-10M 
antenna (http://www.cebik.com/ gup/gup34.html), Rauch warns of the losses and 
other problems short dipoles can present  
(http://www.w8ji.com/short_dipoles_and_problems.htm  ).
    Don's research and trials with EZNEC and TLD help him understand both of 
these expert's points of view led him to believe he has selected dimensions 
for an EDZ and its transmission line to best match an Elecraft K1. Don will 
present a prototype of homebrew 600 ohm ladder line and may have the prototype for 
his optimized EDZ available (but untested) by meeting time.

73, Marilyn, W9LUO



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