I would favor using an inductor. Tune it for the lowest part of the
band. Then using a relay or two, you can short out turns if you want
to move higher in the band. Although I think you will find using Rohn
25, it will be pretty broad.
73
Ken K4ZW
On Fri, May 15, 2020 at 11:28 AM <donovanf@starpower.net> wrote:
>
>
> Hi Ron,
>
>
>
> A more reliable approach is a tuner in your shack. The extra coax
> cable loss from elevated VSWR is insignificant on topband.
>
>
> How high up the band do you want to go and at what maximum VSWR?
>
>
> A resonant Rohn 25 160M vertical will be about 124 feet tall for
> resonance around 1820 kHz
>
> If for some reason you must install a tuner at the feed point of the
> vertical, follow Tree's advice and make it slightly short: 120 feet
> of 115 ft if you need to tune for minimum VSWR above 1900 kHz.
>
>
>
> Use a small tapped inductor to tune it around the band.
>
>
> 73
> Frank
> W3LPL
>
>
>
>
>
> ----- Original Message -----
>
> From: "Tree" <tree@kkn.net>
> To: "Ron WV4P" <wv4ptn@gmail.com>
> Cc: "160" <topband@contesting.com>
> Sent: Friday, May 15, 2020 3:18:39 PM
> Subject: Re: Topband: 160m Vertical
>
> Slightly shorter makes it easy to use an inductor to make up the
> difference. If you make it long - you can do the same with a capacitor -
> but it's typically more trouble than the inductor.
>
> Tree N6TR
>
> On Fri, May 15, 2020 at 8:15 AM Ron WV4P <wv4ptn@gmail.com> wrote:
>
> > I have built an insulated base for a 1/4 wave 160 antenna. The antenna
> > will be XXX' of Rohn 25. In searching I see people using heights from 115'
> > - 130' with a pretty high number around 124'.
> > I do not know how I am going to match it yet, I figure I will do my
> > research on that once it's up so I can learn while experimenting.... But
> > the height has me second guessing. I want it tunable across the band,
> > perhaps using a Tornado Tuner like my JK 801's have with a motorized
> > inductor ? But the question at hand is do I want the antenna Tall or Short
> > ? What is the Method behind the Madness ? :o)
> >
> > Thanks in advance,
> > Ron WV4P
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband - Topband
> > Reflector
> >
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