Topband: [Bulk] Re: Anybody?

[Grant Saviers]

see N6LF's work on 160m top hats 
http://rudys.typepad.com/files/qex-short-verticals-for-160m.pdf

My guess is that informed the DXE design.

Grant KZ1W

On 1/1/2016 12:07 PM, Richard (Rick) Karlquist wrote:
> On 1/1/2016 8:16 AM, K4OWR wrote:
>> :::: Does anyone recall that I originally asked about this?
>>
>> http://www.dxengineering.com/parts/dxe-160va-1?seid=dxese1&gclid=Cj0KEQiAno60BRDt89rAh7qt-4wBEiQASes2tUOULTlQpNyMARBk4ZWRxw70jODW_FJCuBJ1Td47YMgaAhgQ8P8HAQ 
>>
>
>> BILL K4OWR
>
> I looked at the data sheet on this and my intuition
> told me the top hat didn't make sense either electrically
> or mechanically.  I did some quick and dirty
> modeling with EZNEC over perfect ground and
> got a drive impedance around 6-j34 at 1.83 MHz.  I
> then deleted the horizontal skirt wires and pulled
> out the 39 foot top loading wires to a 45 degree angle.
> I then got a drive impedance of around 8-j9.
> A rope tied to the guy anchors in the manual works
> perfectly to do this.  These hybrid wire/ropes then
> become top guys.   Its almost as if this was the original
> design, and then they wanted to make a fancy top
> hat.  The data sheet brags about the
> uniform current in the vertical, but this simplified
> version kept the current within +/-7%.  Good enough
> for me.  I don't have a mechanical modeling program,
> but I don't like the DXE design in that respect either.
> It doesn't lend itself to a falling derrick erection
> method, so you have to use their patented winching
> fixture and bolt it to a concrete base.  It seems like
> this is the hard to way to build a vertical.
>
> I needed an emergency 160 meter vertical a few years
> ago and I made a 60 footer out of 2 30' long
> 3" diameter irrigation pipes with 2 top loading
> wires pulled out.  A third pipe was used as a
> falling derrick.  Pretty simple and it worked great.
>
> Rick N6RK
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