On 5/31/2013 12:43 AM, Tree wrote:
K6SE was the first guy I saw doing this - with much shorter towers than
mine.
Somewhere in my files I have a copy of a four-page letter Earl sent to
K2UU describing in detail the K6SE phased towers -- one of the few
multielement transmit arrays in use on the band in those days (1970s-80s).
If I recall correctly, they were HDBX style 64-foot self-supporting
towers spaced about 80 feet. One had a large tribander on it, and the
other a 2-element shortened 40-meter yagi. Earl described how he raised
and lowered the 40-m. beam on its mast till that tower resonated at the
same spot as the other one. He used identical shunts and a coax delay
line to achieve the correct phasing. His letter included a formula for
calculating this delay line based on the distance between the towers.
This played quite well. We chatted many a night and Earl would flip the
switch and I'd see 25 db f/b or so.
73/Jon AA1K
Delaware
All good topband ops know how to put up a beverage at night.
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Topband Reflector
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