Topband: Beverage Improvements?

[John Battin]

As long as we are talking about terminating beverages, here is a little
trick I use to good effect. I have little spare space for beverages so to
slope the wire at the ends bothered me as I wanted as much active antenna as
possible. I made a 500 ohm transmission line out of scrap 3 inch boom
material cut to be as long as the beverage is high. I put an so-239 near the
bottom and a plastic pet food cover as the end insulator on the top and ran
a #28 wire down the middle (I think the math says #30, but #28 was what I
had). Using a few inches of larger wire on the ends makes it easier to work
with and has little effect on the impedence.   I measured the impedance at
the top with a termination resistor on the bottom and it looked very good.
It seems to work fine. I attach the tube to the ground rod.   Oh yes on some
runs I put a relay inside the tube that switches between a termination
esistor and a transformer/coax feed. I excite the relay with DC on the
coax. With this scheme one wire works in both directions...the disadvantage
of course is you need a feed line to both ends.  73  John K9DX


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