Larry, I think the formula for this is in ON4UN's books. I had a 100-ft tower and if I recall his example for this height was a top hat of 6 spokes with a perimeter wire of 10 feet diameter. Instead I used a 4-el. 6 meter yagi on a 10 or 12-ft boom that got it pretty close -- needed a couple feet of linear loading at the base to bring it into resonance. This was a series-fed tower.
73/Jon AA1K -----Original Message----- From: Topband [mailto:[email protected]] On Behalf Of Larry - K1UO Sent: Wednesday, February 4, 2015 10:27 AM To: Topband Reflector Subject: Topband: Top Loading wires Could someone tell me the length of top loading wires (4 wires planned) needed to add to the top of a base insulated 90 foot Rohn 25g tower to maximize the radiation resistance on 160 meters. I understand there is a point of diminishing returns on the top loading lengths. The 4 wire angles will be around 45 degrees or as close as possible. If I knew how to model ,or even had a modeling program, I would attempt this already relatively simple task to many. From 50+ years of practical experience, I am ‘guessing’ maybe 28 feet long each? _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
