Date: Tue, 6 May 2025 11:34:03 -0700 From: Jim Brown <[email protected]> To: [email protected] 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 _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
