Friday, June 14, 2013

Building and experimenting is half the fun

I was recently able to communicate cross-polar to my antipode to a rare DXpedition, Cocos-Keeling.  Background on it is here.

And I mean BARELY.  The hex beam at 42 feet was marginal at best.  Only after I swapped out the feedline for LMR 600 VERY LOW loss was I able to sneak in a 2-way communication.

I started doing some reading on improved wire antennas, and read the ARRL Wire Antenna Classics text.

One particularly interesting design is the collinear array.  Basically, it's a combination of loaded dipoles in series, end to end, which provide improved gain.  Here's the design for the Franklin array.

Lower height, no towers, cheap, and they work.  I put one up for 17 meters at the low height of a quarter wave in the back trees.  Super stealth.  I am still making measurements, but it appears to pretty good.  This morning for a station in Taiwan it was S4 on the Franklin, and S6-S7 on the hex.