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Old November 1st 06, 01:54 PM posted to rec.radio.amateur.antenna
jawod jawod is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 303
Default two topics one OT and one not

Roy Lewallen wrote:
Sorry, I missed the first posting.

It's a simple matter to reverse the directionality. Self-extracting ZIP
file http://eznec.com/misc/fdsp~.exe contains a program for designing
the antenna and a text file FDSP.txt with extensive notes including
information on how to reverse it. (The original article is at
http://eznec.com/Amateur/Articles/Field_Day_Special.pdf. See the added
notes at the end.)

It's a difficult antenna to model with EZNEC, because there's no direct
way to account for the effect of the dielectric material between
conductors in the twinlead, and this has a significant effect on
performance. The best approach is to use the design program (which does
account for the dielectric) to tell you what the current ratio is, then
model a simple, unfolded 2 element array with that ratio. The example
file FDSP.ez which comes with EZNEC can easily be modified to suit the
purpose. See the accompanying Antenna Notes file for more information.

Roy Lewallen, W7EL


Roy, Thanks for the response. Soounds like I might have bit off more
than I can chew...but I may still try it...installation, at least, seems
a fairly easy project in Ohio winter.

John
AB8O