One of the guys in our local ham club came back from Dayton with a
very interesting new product from DX Engineering. As soon as he
showed it to me, I called up DX Engineering and bought two of them.
The product is a unun autotransformer for HF antennas designed to
transform 12.5 ohm or 25 ohm loads to 50 ohms. This is a natural for
matching any resonant short antenna to a modern transceiver. You
must, of course, do something about the reactive component. Opening
up the box I see good components that will handle some power and
solid, but simple construction. The website data sheet suggests that the
unit should handle 500 watts with a reasonable VSWR.
There are also several variations of hardware to add a capacity hat to a
vertical antennal. While mobile antennas are an obvious application for
both of these products, both could also find good use in a home
antenna farm. Used in combination, I can smell more than a few dB of
improved efficiency. I think I also smell Tom Rauch's hand in the design.
It that's true, many thanks, Tom!
Jim Brown K9YC
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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