At 03:53 AM 10/21/1999 EDT, K7GCO wrote:
>
>It's not 90 db all the way around, I said it was a "deep null." It would be
>very effective in nulling out a strong one. It didn't hurt the gain as is
>normal when F/B is low all the way around. The Quad/Yagi combo did
>it--possibly a first. 48 db F/B is the best I've ever got with yagi's. I'm
>going to build it on 2M first--then 6M--then 10M. This is a design where
the
>variable Xc would be needed or ideal. I can scale any configuration.
I've got a six-pack here that says you won't achieve a 90-db null at HF in
the real world. For one thing, almost any sky-wave propagated signal will
arrive at several different angles simultaneously. Sometimes the different
propagation modes are only a few dB apart in amplitude.
My point was simply that any modeling system is an approximation. You
didn't mention what you're modeling with, but MiniNEC requires some special
precautions when modeling quad loops. NEC-2 doesn't have that same
limitation, but has others, particular WRT conductors of different sizes,
as well as a number of others.
73, Pete N4ZR
Sometimes a tower is just a tower
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