Perhaps I should have said MONOBAND DIRECTORS
cannot be lined up in front of multi-band Driven Elements.
When I modeled a 3L15 inside my Telrex 3L20, the best
I could achieve was 2 dB LESS gain than for the 3L15
by itself due to destructive interference from the 20M
director.
TRAPPED directors prevent the associated problem.
Apparently Force 12 has been able to resolve that issue
with closely coupled open sleeves (see the 10M directors
on EACH SIDE of the 20M directors on the C31 which
has 7 elements on 10M but gain figures correspond to
a 5L monobander).
Correction: my description was of the C3, not C3S.
The C3S has 3 REFLECTORS, one each for 10, 15, 20
and NO directors. IMHO, this is a VERY GOOD 2L
design.
de Tom N4KG
On Wed, 4 Apr 2001 "David J. Windisch" <davidw@copper.net> writes:
> SNIP>>>>>>>
> REFLECTORS can be
> lined up in band order but DIRECTORS cannot.
>
> de Tom N4KG
>
> Hi, Tom:
>
> Then, iyo, CushCraft, HyGain, et alii, haven't 'done it right' with
> their multi-director arrays?
>
> 73, Dave, K3BHJ
>
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