Topband: Quarter wave sloper on crank up tower ?

[jim.thom jim.thom@telus.net]

Date: Tue, 6 May 2025 11:34:03 -0700
From: Jim Brown <jim at audiosystemsgroup.com>
To: topband at contesting.com
Subject: Re: Topband: Quarter wave sloper on crank up tower ?


>Hi Jim,

>There are many ways to skin that cat. It's pretty well known that radial
>systems don't need to be anywhere near ideal to work. The radial system
>for my Tee vertical covers about 220 degrees. In 19 years, I have 173
>confirmed on topband.

>These are slides for a talk I've done at Visalia, Pecificon, and to
>several clubs. Mostly it talks about radial systems and other
>counterpoises.


>73, Jim K9YC

The concept behind the 1/4 wave sloper is...... the 50 ohm feed point is at
the top of the tower...90' above ground.    And if it's less than 50 ohms,
a simple helical hairpin  across the feedpoint is one solution.

To cover more of the band, it's a simple matter to use a loop at the top,
then shunt it with a DPST  vac relay.   Then no matching network  required
in the shack.

I have used 1/4 wave slopers on 75m  since 1977, on various
height towers...up to 96'.
Never tried a 1/4 wave sloper on 160m though.  That's why I was asking.

I have zero enthusiasm for installing radials below the existing lawn...
but it is doable.

Jim  VE7RF