Hi Alan ...
Hi Marcus, I have not much experience with ferrite rods, but the article
in
Electronics World for August 2002 (mentioned in an earlier posting) does
evaluate various rod configurations for efficiency. I think the conclusion
is that you cannot achieve the effective height that you can easily
achieve
with an open loop. They measure a 0.77m diam 38 turn loop with an
effective
height of 9metres !! The best performance ferrrite rod aerial was an
effective height of 1.8m using 12 rods 200mm x 10mm. They dismiss it as
usefull only as a portable test aerial.
Well, I don't have this article but the figures you'd mentioned was enough
to make me review some concepts.
I have a loop but using .5mm computer flat cable - those used to connect
HD/floppies to computer board - and the coupling via 1 turn loop, 30 turns
on a octagon PVC structure with 6 meter perimeter. The wire spacing is
roughly 1mm BUT there's the flat cable PVC dielectric. So the ressonance was
much lower than predicted the Rejloop program.
Seems that I'll have some hard (but not so) work winding this air loop with
#24 gauge, some milimeter spacing ... and migrating the ferrite rod
pre-amp/tunning ckt to it.
No pain no gain ... :o/
Thanks on the comments ...
73
Marcus
PY3CRX/PY2PLL
S. B. do Campo - GG66rf
http://py.qsl.br
Active from "DC" to 24GHz
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