[TowerTalk] shunt feeding tower on 160

[nn4t at comcast.net]

Good afternoon. I have 118 feet of Rohn 45G which, at the moment, has no antennas on it. It is guyed in 3 places using Philly and sits on 1.5 cubic feet of concrete with a pier pin at the base. The tower is grounded (three 5/8" 8 foot rods per leg, spaced at 20, 40 and 60 feet from the tower in a line and all connected with #2 copper) and I have layed out 33 130' radials (#14 stranded copper, insulated) as the ground screen. If you disconnect the ground rods (not the radials) the tower has a resistance of 37 ohms at 1.830 and an SWR of 2 (according to my MFJ 259B). I would prefer, however, for lightning protection, to leave the ground connections in place and use a gamma wire and capac itor to match the tower for use on 160. I have tried, using a wire running from near the top of the tower, and with spacing from the tower varying from about 28 down to 14 or so inches, to find the 50 ohm tap point for the tower. This seems to occur, interestingly enough, at about 3 feet off the ground. Since this seems a bit odd I consulted local antenna guru, N4KG, and he too thinks the tap point should be significantly higher, at least 30-40 feet if not more. I don't have much experience with this to draw on so I would like to ask the group for ideas or input. This also seems to vary quite a bit from articles I have read on the subject in the ARRL antenna book and in Low Band DXing, although virtually all of those articles concern towers with some sort of top loading provided by yagis. Thank you in advance for your advice, Steve, NN4T