Ryszard Tymkiewicz wrote:
> ...
> Jim I agree with Don K5AQ.. My tower is slightly higher ..18 meters and the
> yagi is just above it.
> I was using 1/4 wave sloper for almost 15 years and I'v thought its the best
> solution (#280 wkd using that sloper),
> but 3 years ago I tuned the tower and I used gamma match..the difference
> between 1/4 wave sloper and
> matched tower was 1 to 3 S...favouring the tower. Its easy to make and to try
> it....
Hi Rys,
My tower is 58 feet tall and supports an LPDA at 60 feet (plus some 6m
antennas at 70 feet, but they don't influence the top-loading
significantly).
Regarding your shunt-fed tower:
- What kind of radial system do you have for the tower?
- What wire or tubing size do you use for the gamma "rod""
- What is the rod-to-tower spacing and how high up is the tap point?
- Do you use a single series capacitor or an Omega match (two caps) at
the input?
I ask because I am currently using a 1/4-wave sloper and would like to
try the shunt-fed arrangement again. I had used a shunt-fed tower at a
previous QTH with good success, but haven't done it here due to a very
limited area for a radial field on a city lot.
Cheers,
Gus Hansen
KB0YH
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