At my mountaintop QTH I am trying a new antenna as my 3 elements 40 meters yagi
broke in the winds:
It is an 18 meters high aluminum tower with a vertical on it.
The vertical measures 9.80 meters (so total height is 27.8 meters).
The vertical is fed with gamma match on 40 meters and four 10 meters radials
come down at 45 deg angle as counterpoise (GP) on 40 and they are also working
as capacity hat on 80 meters.
At some height (pheraps 10 meters from the ground) I will put two horizontal
radials for 80 meters and feed them against the tower for 80 meters.
1) Do I have to put some wire/capacitor traps aside the tower to isolate the
lower section under the 40 meters vertical to avoid radiating ?
2) Do I have to put sone wire/capacitor traps aside the tower to iisolate the
lower section under the 80 meters radials to avoid losses ?
3) Do I have to do both ?
4) Can I put a 160 meters inverted L antenna just few meters from this tower ?
5) I do have a big ground screen composed by 100 32 meters long radials on the
ground...do I have to isolate these from the verticals/ground plane antennas ???
6) Do you think it is better to put a delta loop (vertical radiation) instead
of using this GP arrangment ?
Best regards and 73 de Fabio, IT9GSF.
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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