Bill:
You are correct as to the antenna performance. Relationship to nearby
objects, trees, bushes, houses, and etc will have a marked effect in antenna
performance, especially with verticals. As to radials, they ideally should
be spaced equally and "radiate" in all and equal directions from the base of
the antennas. However, any number of radials in the ground, wandering
around any place, around the house, around the flower beds and etc will be
much better than no radials at all. Verticals which are reduced electrical
length don't perform as well as full size verticals. It's easy to get a 10M
to 20M vertical to work quite well. After all a 20M 1/4 wave is 16 or so
feet. A 75M 1/4 wave is 66 ft or so. Therefore, the physical size of the
20 - 10 M vertical is closer to the electrical wavelength. Thus it is
nearly a "full size" antenna.
When I lived in FL I had 2 antennas, one a Butternut HF6V with WARC bands
and a center fed 125 ft wire. I had the Butternut set up for the digital
portion of each of the bands. The wire antenna used a balanced feed and a
tuner. I tuned it to the frequency I wanted to operate. I noticed when
working digital modes that as a signal went into a fade on one antenna it
was most often up in strength on the other one. From that, I made a timed
and sequenced switcher. When I noticed a signal beginning to fade, I
manually flipped a switch and during the next non-transmit interval the
system swapped antennas. I made many QSOs that way and rarely lost a
contact.
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