THose who have been on the list a while will remember that I expressed a
question mark in my notes on the Tee match: were the results correct or
were they an artifact of modeling--in other words, did NEC-4 have some
unadvertised limitations?
The answer is yes--NEC-4 has some limits. Too long for posting, I have
placed my notes on both stepped diameter limitations and on unequal
diameter wires in parallel and right-angle configurations at my site. I
have also withdrawn the notes on the Tee match pending some alternative
modeling exercises in MININEC and MININEC PRO.
The bottom line is this: NEC-4 is off base (and NEC-2 is in another ball
park altogether) when you closely parallel wires of different diameters
(as in a folded dipole for transformation ratios other than 4:1) and when
you join wires of unequal diameter at right or sharper angles. MININEC,
with due caution, takes these situations in stride.
-73-
LB, W4RNL
L. B. Cebik, W4RNL /\ /\ * / / / (Off)(423) 974-7215
1434 High Mesa Drive / \/ \/\ ----/\--- (Hm) (423) 938-6335
Knoxville, Tennessee /\ \ \ \ / / || / (FAX)(423) 974-3509
37938-4443 USA / \ \ \ \ || cebik@utk.edu
URL: http://funnelweb.utcc.utk.edu/~cebik/radio.html
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