In a message dated 11/10/01 3:43:23 PM Pacific Standard Time, w6ru@bak.rr.com
writes:
<<
Looking for information on phasing two 1/2 wave diapoles for 75 meters. I
plan to have them come off the tower at the 110 foot level and be at about
45 degrees. One sloping towards shortpath europe and the other long path
europe. I am planning to use equal length feedlines. Is there a way to feed
these and get some front to back ? Maybe with a phasing delay line in series
with one antenna's feedline ? Any help or suggestions where to get info
would be appreciated.
Thanks Much,
Terry W6RU
>>
Terry: Yes there is. I thought you'd never ask! Some 25 years ago someone
marketed a box that with 2 equal length coaxes feeding 2 inverted vees about
.15 WL apart. You could vary the phase and obtain a low SWR match to the
inverted vees to point the pattern either way tuned for gain or F/B. It
would take about 500W. I have one but it's packed. I'm going to build a
larger one. It would work on 2 vertical also or even stacked beams for some
experiments. I want to make a 3 and 4 input version with an amplitude
control also.
Someone asked me about it a couple of months ago and I don't know if he found
it or not. Some one out there must have the circuit. Make yourself know.
K7GCO
List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 100 feet for under $1500!! http://www.anwireless.com
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|