[TowerTalk] Raised Radial Spacing

[Steve Maki]

> 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
>

My 160M TX antenna is a center fed vertical dipole, more of a capital I 
than a sideways H because I have a couple tall towers to suspend it 
from. But it works so well that if the towers were shorter I would use 
the sideways H version without hesitation. I've got a CM choke at the 
feedpoint. The 'bottom' hat is ~15' off the ground.

-Steve K8LX