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Steve Bonine · September 28th 07, 02:01 PM posted to rec.radio.amateur.moderated

wrote:

The big problem with HF/MF antennas for the radio amateur is that
the best choice is so dependent on the site and what the amateur
intends to do. This is why it is impossible to give general advice
about HF antenna types that is any good, without knowledge of
the available resources and intended use.

That's a very good point, especially in today's world in which so many
people live in close proximity to their neighbors and there are often
restrictions on what can be erected for an antenna. My mindset tends to
be stuck back in the 60's suburbia where the biggest problem was where
the trees were in relation to the length of the skyhook desired, and no
one particularly cared if ladder line was more unsightly than coax.

This line of thinking reminded me of a rather unique antenna-related
probem that one of my childhood Elmers faced. The transmitting antenna
for one of the 100 KW clear-channel AM stations was literally in his
back yard. His antenna was a long wire that fed directly into the
shack, and he grounded it when not in use with a knife switch. When you
opened that knife switch you could literally draw a small arc of RF from
the nearby transmitter. He shunted this unwanted signal to ground
during operation with a low-pass filter, but it did create an
interesting show for us wide-eyed young visitors to his shack.

I don't know how much bypassing and other fiddling he had to do because
of the ambient RF level just from being that close to that much RF. I
wonder how many of today's hams, faced with this obstacle, would simply
decide that operation on HF was not possible.

In fact, I wonder if today's FCC restrictions on exposure to RF would
even permit houses that close to a 100 KW transmitter.

73, Steve KB9X