Bob,
The Tornado coil is a motorized inductor that compresses or expands the coil to
change inductance. It was developed by Seco-Systems, not N6BT. They are heavy
and expensive but cool.
To the best of my knowledge anyone can buy those from Mike at Seco-Systems. I
know Force 12 has bought them in past for center loading on big low band
dipoles or verticals.
The larger air wound coils with Delrin on each side may approach the properties
you would see using the Hamwaves inductance calculator.
http://hamwaves.com/antennas/inductance.html
Wish they would add option for inches :-)
Hope this helps in some way.
73... Stan, K5GO
> On Jan 3, 2016, at 12:23 PM, Robert Harmon <k6uj@pacbell.net> wrote:
>
> I found this interesting article (below) on the evolution of Force 12's
> current Tornado loading coil design from
> the beginning with the Tom Schiller, N6BT original design to their final
> Tornado version. I put this post on the EHAM antenna reflector but no
> interest yet.
> I was surprised that in the last part of the article they say that they wont
> disclose the Q of their new Tornado coil. Huh ???
> Reading thru the article it indicates they went away from Tom's original
> design to a smaller dia, smaller inductor,
> loading coil design, and now they have gone to their new Tornado design which
> looks very similar to Tom's
> original design. hmmmmmmmm
> I have surmised from this that they developed a piece of #### loading coil,
> then went back to a slight variation,
> original design, higher Q, more efficient coil they named Tornado. It bugs me
> that they wont divulge the Q,
> my guess is that they dont want us to compare the Q's of the loading coil
> evolution from Tom's original design
> to the current Tornado. I think we know why they dont want us to compare :-)
> Anyway I am trying to figure out the Q of the different coils.
>
> here is the article:
>
> http://www.force12inc.com/content/Application%20Note%20-%2040m%20Delta%20Coils%20Overview%20DRAFT%202.pdf
>
>
>
> 73,
> Bob
> K6UJ
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|