Hi Gang , Richard here:
I am putting up 3 sections of regular TV tower soon. I plan on topping it with 32-33 feet of piping. that should be 1/4 for 80M and 1/2 for 40M. It will be on a cement pad and supported by the house 18 feet from the ground . So I guees thats a grounded Structure. I heard of Shunt feeding these , like a Gamma feed . Can anyone give Me advice on this , like "Ballpark" figures where to start from. Rod lenght , spacing , Shorting strap and Cap value if needed. I would like to go 80/40M if it can be done ..
73 .....VA3VJC / Richard
"I plan on topping it with 32-33 feet of piping." Better plan on guying all this. Don't forget you need a bunch of radials. Google turned up 700 hits on "shunt fed tower". I see lots of great info there, even on the first page.
Also, for additional good articles:
Ham Radio Mag. Nov. 1979
QST Oct. 1982
QST Jan. 1984
'QST June 1984
You can also go here:
http://www.arrl.org/tis/and search the QST Index (if member) and also the CQ and Ham Radio Mag. Indexes for "shunt fed tower" articles.
I did a shunt feed of my tower for 160 meters years ago. Always seem to be a noise magnet.
Finally went to an inverted vee. Actually your tower plus additional mast would make a nice center support for inverted vee type antennas.