[TowerTalk] "Magic" length from tower to first insulator

[Larry Loen]

I could imaginably insulate my guys from the tower sections, because I am
using the Rohn brackets to attach them.  I would have to find some suitable
material before the tower went up, but I have time for that if I know what
to select (would want it to be UV resistant if possible, though the bracket
itself will give some sun protection).

I _think_ this helps or at least simplifies the analysis, because it should
take the tower sections themselves out of the picture.  If I understand the
discussion, it would also mean that it restores the tacit assumptions of
the original ARRL paper (albeit without Mr. London's sophisticated
modelling and analysis).

I also wonder if the second set of guys are grounded (which I intend to do
anyway), makes a difference in how the secondary lengths resonate?


WO7R

On Wed, Mar 16, 2016 at 10:51 AM, jimlux <jimlux at earthlink.net> wrote:

> On 3/16/16 9:47 AM, Richard (Rick) Karlquist wrote:
>
>> On 3/16/2016 9:01 AM, Larry Loen wrote:
>>
>> Comments?  Dissents?  What did I overlook?
>>>
>>>
>> What you overlooked was that if the wire is
>> not insulated from the tower, the resonance
>> is at 1/4 wavelength not 1/2 wavelength.
>>
>
> Seems reasonable (e.g. the tower is "big" compared to the wire, so it's
> sort of like a 1/4 wavelength whip over a ground plane..)
>
> I wonder if that's how it works in reality, though?
>
> Maybe that top guy segment (connected to the tower) is really a very long
> wire that happens to be bent at the end, and doesn't feature into the
> circuit?
>
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>