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

jawod wrote:
I recently posted regarding an antenna that Roy, W7EL designed back in
the 80's for backpacking (FD Special: directional array). I was a
little disappointed at no response but such is life.

Any thoughts as to whether this is a good approach to a home QTH antenna?

I was considering reconfiguring it for 17 meters and trying EZNEC for
the first time (if I can get the program to work on my new MacBook).

The antenna (20M version) consists of two elements separated by about 8
feet and the ends connected to a PVC pipe for support on each end
---[======]---

The antenna is 300 ohm twin lead and the feedpoint is in the center with
a 1/2 twist phasing line to the other element. 330 pF caps are used at
the feedpoint for matching.

I asked whether it might not be too difficult to reverse directionality.
(there's an article in QEX about that, in general, this month).

Any thoughts are appreciated.

2nd (OT) comment:
. . .