From: Aa4xx (firstname.lastname@example.org)
On Mon, 26 Jun 1995, Rick Zabrodski wrote:
> The above is fine for monoband perfomance....has anybody built a phasing
> box to allow multiband use? How did it work? Plans?
Two years ago, I built a continuously variable phasing box which
covers 80-20 meters, which is presented in the ARRL Antenna Compendium,
Vol 3. This design works very well. I originally used it with two Gap
Voyager verticals on 80 and 40 meters for DX work. Typical F/B ratios of
25-30 dB are easily obtainable.
For this year's Field Day, I used two 40 meter inverted vees, 35
feet apart, fed with this phasing box to make a 2 element inverted vee
wirebeam. The wirebeam was oriented North/South. Results were very
encouraging, with about 6 dB gain over a reference vee, and F/B ratios
approaching 30 dBd on some signals. To change direction, all you have to
do is flip a toggle switch, and bingo, you're ready for action in the
opposite direction. It was really neat to be operating from NC, and be
able to instantly determine if the station was North or South of my
location simply by flipping one switch.
This box is relatively easy to build, and the cost is moderate,
about 75-100 bucks for all the parts. I'll be glad to share any ideas
for anyone who might like additional information on the phasing box.
Having the additional gain made it seem like we were running QRO.
There were very few requests for repeats, and the QSO rate was pretty
good throughout the 24 hours. 72,
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