[TowerTalk] Press release Re: F12 ants !!

[Wes Stewart]

So they take a Force 12 model, change everything about it and still call it a 
Force 12?

Wes  N7WS

On 5/11/2017 9:54 AM, Jim Thomson wrote:
> ## Apparently,  JK antennas in CT,  will be building some select models of legacy F12 ants, yagis + verts.
> But  each select  F12 ant will  be completely re-optimized to  NEC-4 pro standards.   EG, F12s  5BA has been
> re-designed, with fewer eles, and more gain, better performance.  They will also be  completely
> re-designed  mechanically  to  JK antenna  standards.
>
> ##    F12 used the now obsolete  RS-222-C method for determining wind loading.
> The problem with the 222-C spec is the effective area was used, instead of the actual projected area
> of a cylinder.   IE, what F12 called  6.67 sq feet is actually 10 square feet.   You have to take the
> old F12 square footage..and multiply by 1.5   to get reality.
> The calculated V max, using 222-C is incorrect.  Ken Garg at JK antennas uses the newer standard,
> as in what you actually measure inside a wind tunnel.   Mosely, Hy-gain, M2 are still using the old 222-C spec.
> 100 mph using the wind tunnel spec, = aprx  112 mph using the old 222-C spec.
> 100 mph using the 222-C spec is in reality, aprx 92 mph using the new spec.
>
> ##  new versions are built a lot stronger, handle ice loading,  and a real 100++ mph wind, etc.
> The re-designed select F12 ants will augment the superb, existing line up of JK ants.
>
> https://jkantennas.com/news.html
>
> Jim  VE7RF
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>