Let me add another few cents worth...
Theoretically, two small loop antennas can have a nicely improved front lobe
and, as Tom points, with 180 degree phasing (I prefer about 165 deg.), can
add nulls in other places to improve overall directivity.
I did several experiments with this configuration three years ago. I tried
two K9AY loops inline at 50 and 70 foot spacing. Close spacing (i.e. 1/8
wavelength or 70 feet on 160M) and near-180 degree phasing are a lossy
combination; signal levels were down 6-8 dB from the already low levels of a
single loop and I decided not to put in further effort.
Things are much better behaved and there is real gain up to 3 dB if you can
get the spacing more like 3/8 to 1/4 wave. At this point, however, much of
space-saving advantages of the small loops has been lost.
Broadside and arrays are actually the easiest to implement successfully --
phasing is in the range of 0 degrees and the larger aperture means that you
get both better directivity and gain. They can be steered +/- 15-20 degrees
with a 45-degree (typical) phasing line. A broadside array of loops may be
a good option for a ham with long, narrow property. A Beverage works along
the length of the property, while 2 or 3 broadside loops can provide
coverage to the sides.
Jeff -- the semi-broadside array should be workable.
73, Gary
K9AY
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