Topband: Top Loading wires

[Jon Zaimes]

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:topband-bounces at contesting.com] 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?



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