Jerry,
My head is spinning after 30 minutes of trying to compare our figures.
I'm sure you wont believe this, but I believe there is a bug in EZNEC.
I loaded up the vertical model I was using last night - 132ft over
Real/MININEC average ground, Aluminium Wire Loss, and re-ran the
figures. My numbers were several dB higher than yours. I then switched
to Perfect Ground and Zero Wire Loss to check my Average Gain figure -
it was very low. Then I switched straight back to Aluminium Wire Loss
and Real/MININEC ground and got a completely different set of figures -
very close to yours.
I repeated the exercise from a "cold start" (closing down EZNEC and
restarting it) about 6 times and consistently saw the same thing - an
erroneous set of figures at first, and then a correct set once I'd
swapped to Perfect Ground and back. I was trying trying to bottom-out
exactly which change caused the change in behaviour, when it stopped
doing it and I now can't reproduce the effect.
I wonder if anyone else has ever seen this? Please don't suggest it was
"operator error" - once I'd first identified the effect I was very
careful to check and double-check every setting.
Steve G3TXQ
K4SAV wrote:
> G3TXQ wrote: Are we sure we're looking at the EZNEC results carefully
> enough.
> If I compare a 160m half-wave at 300ft with a ground-mounted
> quarter-wave vertical, over average ground, the vertical has the
> advantage at take-off angles under 10 degrees by as much as 8dB.
>
> Well Steve it's obvious one of us is not looking close enough. I
> can't get that. Are you sure you're not using a perfect ground for
> the vertical? When I said no near field ground loss, that implies a
> Mininec ground.
>
>
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