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AM antennas - RF Cafe Forums
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| Qacer
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Post subject: AM antennas
Posted: Wed Aug 24, 2005 11:12 am
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Joined: Sat Apr 23, 2005
2:09 pm
Posts: 17
Location: Tampa, FL
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Hey all,
Anyone know of any improvements
regarding AM antennas? I've been doing some reading
and found some interesting articles regarding the
DLM (URI Robert Vincent) and EH (Ted Hart) antennas.
I'm curious if there are others out there. I'm
especially interested in smaller AM broadcast antennas
that are "close" to commercialization.... if there
are any.
Thanks!
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billspcs@aol.com |
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Post subject: am MW antennas
Posted: Wed Sep 14, 2005 12:53 pm
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Hi
Nothing beats
a good resonated loop for MW BCB DX. The higher
Q loops even help selectivity in addition to being
directional- if ur listening to AM broadcast, diretionality
is important, due to co-chanel reuse with georaphic
diversity [the FCC broadcast model]. Also a loop
will allow U to point it to the ionosphere for listening
at to skywave night for distant stations while rejecting
the groundwave of the local station. The hardest
thing to get is the tuning capacitor-- a real air
varible is the best-- varicaps just dont have the
dynamic range for over the air broadcast without
esoteric circuits and a lot of care. Look at kiwa.com
for a good small MW loop-- this is my friend Craig-
a good guy who sells honest products-- small shop.
He used to make a huge loop, but discontinued it.
One other thing-- make the preamp and capcitor fully
differantial and balanced to ground for best null
rejection. Unbalancing a loop ruins it-- I know
where to get dual air varibles too--this post could
go on for days-- so i will stop for now.
bill
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Posted 11/12/2012
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