Tune your Tower
Jack Schuster, W1WEF

YCCC Scuttlebutt #119, October 1995


Ever put up a half sloper and have a hard time getting it to resonate? I have. Sometimes they seem to resonate fine, but at other times I have put them up and just couldn't get the SWR down no matter what.For those unfamiliar with these antennas, I'm referring to a quarter wave sloping wire from the top of the tower, or close to the top, sloping downward at 45 degrees, fed at the top with the shield of the coax tied to the tower.

I've been using a half sloper on 160 for a couple years now, with good results. It comes off my 100 ft tower at the 90 ft level. I can tune it to have a perfect 1:1 SWR at any place in the band, by "tuning" the tower half of the antenna in a unique manner. At about 80 ft, I have a shunt wire that I used to use for a shunt feed until a low TH6 I added messed it up.

The shunt is spaced about a foot from the tower and runs to a gamma capacitor at the bottom, through which I used to feed it. Instead of feeding it with coax, I have grounded the side the coax used to con-nect to, and can tune the capacitor to make that half sloper play anywhere in the band!