Re: Topband: Looking for user experience: DXEngineering Thunderbolt 160m vertical

[Wes <wes_n7ws@triconet.org>]

Or reduce the loading to present a capacitive reactance at the feedpoint and 
shunt it with an inductor.  Functions as a step up L-network and presents a 
ground at DC.  That's what I do here.
Wes  N7WS


On 12/5/2020 7:35 AM, Rudy Bakalov via Topband wrote:
> 
> P.S. If your vertical has a good set of radials, you will see about 35 Ohm feedpoint 
> impedance. You may want to wind your own unun using Jerry Sevick’s cookbook
>
> http://www.introni.it/pdf/Amidon%20-%20Transmission%20Line%20Transformers%20Handbook.pdf
>
> or buy a readymade 35 to 50 Ohm unun from balundesigns.com
>
> The third option is to build a coax transformer per PA0FRI.
>
>
>
> Rudy N2WQ
>
> Sent using a tiny keyboard.  Please excuse brevity, typos, or inappropriate 
> autocorrect.
>
>
> > On Dec 5, 2020, at 8:37 AM, David Aslin G3WGN <david@aslinvc.com> wrote:
> > I'm building a contest station and the time has come to make a choice of 160m 
> > TX antenna. Looking at DXE Thunderbolt I note that the capacity hat extends to a 
> > significant distance down the vertical section. It's my understanding that will shield 
> > some of the radiation from the upper part of the vertical. Alternatives like a 
> > vertical tee would not have this issue.
> > Is my understanding correct?
> >
> > I'm considering a commercial antenna as high strength telescoping antenna 
> > tubing is unobtanium in UK.  My QTH is an exposed windy location so strength 
> > matters!
> > 73, David G3WGN M6O
> >
> >
> >
> > Sent from my Galaxy
> >
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