That doesnt work for us that have solid rock as the tower base. My 180' has solid granite at 8-14" below grade and the other 3 towers arent much better, I think the deepest spot is 2' of sandy gravel.
The 80-100' pines make good lightning arresters and their roots are horizontal. I push them over with a front end loader bucket. Carl KM1H ----- Original Message ----- From: "DAVID CUTHBERT" <[email protected]> To: "HAROLD SMITH JR" <[email protected]> Cc: <[email protected]> Sent: Friday, July 27, 2012 11:36 AM Subject: Re: Topband: Lightning protection >A low impedance tower ground is important. Google TOWER FOOTING RESISTANCE > for an IEEE ppt. on this. I would aim for a couple of ohms. That means > several long rods. > > Dave WX7G > On Jul 27, 2012 9:06 AM, "HAROLD SMITH JR" <[email protected]> wrote: > >> About 20 years ago I decided to do something about lightning protection. >> My tower is 80 feet of Rohn 45G, with a 5el Telrex monoband 20 meter yagi >> at 82 >> feet. >> >> Hygain 153BAS at 90 feet and Hygain 103BAS at 100 feet. I have a homemade >> antenna >> >> switch box near the top. >> I shunt feed the tower with an Omega Match for 160. The shunt rod is >> 1/2inch EMT >> conduit. >> >> I use vacuum variables in the Omega match. >> At 65 feet I have a Diamond X200 for 2meter/440mhz. all cables come to >> the >> base >> and go underground >> >> to a steel box at the entry to the house. The HF antennas are fed with >> RG-17 and >> go through an ICE >> >> 308 15kw coax arrestor. The X200 is fed with RG213 through a PolyPhaser >> arrestor. The control wires >> >> all go through PolyPhaser arrestors. I made LC to UHF adapters. >> My tower is the tallest thing for several miles. The tower is guyed with >> 6700lb >> Phillystrand. >> So far so good. >> >> Price W0RI near St. Louis, MO >> _______________________________________________ >> UR RST IS ... ... ..9 QSB QSB - hw? BK >> > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1424 / Virus Database: 2437/5158 - Release Date: 07/27/12 > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
