[TowerTalk] Raised Radial Spacing

[Jim Brown]

On 10/28/2025 7:15 AM, john at kk9a.com wrote:
> Back when N6BT owned Force12 they manufactured Sigma vertical dipoles.  It
> was a sideways H shape fed in the middle and it had handmade wire inductors
> to reduce the length.  I always thought that was a pretty good antenna for
> its size and ease of installation.

Tom has done a lot with loaded vertical dipoles. It's a very interesting 
concept. W6GJB has built some that we've jointly designed, based on his 
ideas. One of them, for 80M CQP and 7QP county expeditions, worked quite 
well, but got destroyed in the wind because the Spiderbeam pole we used 
wasn't built the way the vendor said it was, and didn't have the 
mechanical strength they claimed. Glen is a fine mechanical engineer, 
retired from the space program.

In extensive RBN testing, it outperformed an inverted vee with an apex 
at 50 ft by more than 6 dB.

73, Jim K9YC