Gents,
Since I am still active duty USN I needed an antenna that would prove to be
rugged and yet easy to disassemble if I need to move again (8 moves in 13
years).
For top band being the focus and 75 meters a close second here is what I did
as a compromise to ease of assembly and good performance:
35 feet of vertical using (4) 5 foot sections of tv mast and the top 15 feet
being aluminum left overs from other projects.
Three top hat wires all of which are 35 feet in length attached at the top
of the 35 foot vertical section. I wanted to have four but they would not
fit well on this city lot. Unfortunately I can not get them any higher than
at a drooping 45 degree angle from the vertical plane but I will have to
live with it.
The ground radials are all elevated up on the roof since the base of the
vertical is at the roof level. I have 12 radials all of which are 50 feet
long. I will be adding five 100 footers tomorrow in the morning.
Using hit and miss 'technology' it looks like the vertical needs around 23
uH of L at the base to get it to resonate on 160.
When it is all said and done I have the antenna but no one is on the band. I
had a friend locally get on with me and I tried tuning the antenna from the
shack going via the tuner WITHOUT the extra loading coil at the base. THEN,
I put the loading coil back in the circuit at the base and he said I picked
up 5 S-units. I thought that was interesting. Final tuning is not yet done
as I still need to use the antenna coupler in the shack to match the
antenna, even with the coil in line.
I wonder if it would be better to feed the antenna with ladder line but yet
still keeping the remotely switched coil at the base for 160. Bypassed for
75 meters. Also I wonder how it will work on the higher bands other than 20.
used it on 20 tonight and had a blast working lots of dx all over the place.
Coil bypassed and using the coupler in the shack.
Anyway, just thought the group might like to hear abt the latest in the
antenna department. Look for me on 160!!
Lane Zeitler
Ku7i
San Diego
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