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Old May 24th 05, 05:14 PM
Tam/WB2TT
 
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"Wes Stewart" wrote in message
...
On Sun, 22 May 2005 21:26:49 -0400, "Tam/WB2TT"
wrote:


"Wes Stewart" wrote in message
. ..
On Sun, 22 May 2005 17:41:22 -0400, "Tam/WB2TT"
wrote:
[snip]


Tam uses a single wire at the middle of the dipole to contain the
source. This is necessary because NEC doesn't allow a source at a
wire junction. (EZNEC has a split source that works at a wire
junction, but not a multiple wire junction.)

The EZNEC manual recommends that this wire be at least 0.02
wavelengths long and consist of three segments. I believe the three
segment rule is stipulated to force the segments adjacent to the
source wire to be equal to it. If we are careful about this, we can
go to one segment.

Tam's center wire is only 0.2 feet long and has 11 segments. The
segment length of .018 feet is way too short; the wire needs to be
~16' long at 3.5 MHz to meet the guidelines.

Of course with this gross violation comes another one when the
connecting wires are a more appropriate segment length.

Tam, I suggest that you got to Options--Segmentation Check and make
it "Auto".

I'm still looking at this issue and will report back if I see any
progress.

Wes N7WS



Wes,
Thanks for pointing it out. I did this in a hurry, and did not notice the 11
segments in the .2 ft wire. I will take a look to see if it is any different
for 1 segment. In fact, I might make it +/- 1 foot long.

Tam/WB2TT