In the late 80ies – early 90ies MTV ran a campaign that said ‘Books feed your head’. How true. So what does a ham radio freak feed his brain? Right: antenna books! One of my favorite books is Simple and Fun Antennas for Hams (an ARRL publication). It’s a book full of practical antenna designs and ideas. No rocket science formulas or complicated theories. I have those classic reference books as well but I saw this publication on a ham fair years ago and I couldn’t resist. Sometimes you need a design plan that simply says "measure that long – cut here – solder there". The book is full of those plans.
Since I have a K3 now thus gaining 6m access, one of the issues that kept my mind busy lately was: "what antenna to make for 6m". It should be very cheap, ultra light, small footprint, easy to construct and even easier to put up. No big yagi or quad. I’m not planning to set 6m records nor work 6m firsts. I just want to see what the 6m fuss is all about. I considered a 2el yagi, a moxon, a vertical, a dipole, a sloping dipole etc. To get some inspiration I sent Google to get me some ‘6m antenna’ ideas. One of the antennas that popped up after a few clicks was the Hentenna. I immediately connected this name to the Simple an Fun book mentioned above. It is described in this book and I remembered the design as a simple antenna with a few interesting aspects for the upper HF bands (small, cheap, light etc). So Thursday night I grabbed the book off the shelf and took it to bed to review the design plan. Friday morning (a day off!) I woke up at 6 AM or so. One hour later I was in my workshop (garage, storage room, dog house, whatever) constructing the 6m hentenna. I collected all parts from my huge collection of junk parts and odd ends. The job got interrupted by the daily life and I resumed building in the evening.
The odd thing was that the ARRL book said to connect the feedpoint 1/6th of the length measured from below while the online article said 1/10th. I esteemed the ARRL book more trustworthy than an obscure web site. After all the book is edited by N6BV – the ARRL’s antenna guru. The job was done and I put it up with a rope and pulley on my tower. No resonance. SWR sky high. Dimensions were right and connections were checked. Nothing. I assumed the tower was coupling because it was too close so I moved all the stuff (coax, antenna analyzer, antenna, tools) to the other side of the garden to my 80m elevated radial support with extra free pulley. Same story. It was 9PM local and I was very tired. Note to self: collecting stamps – no fuss!
My last resort was to lower the feedpoint from 1/6th per ARRL instructions to 1/10th as per website (DL1GSJ). You know what? BINGO! DL1GSJ 1 – ARRL 0. Resonance and SWR 2:1 or lower right at the feedpoint which is about flat in the shack due to cable losses. I didn’t care to prune any further. I moved everything back again to the main tower and raised it to 8 meter high. I needed to free our cat because one of his paws got entangled in the rope. Always fun, pruning antennas with those four legged rascals playing. The analyzer showed a perfect graph so I ran upstairs into the shack and tuned to 50 MHz. The problem was I only heard the beacon ON0SIX with S4 and QSB… I hope to test it soon during one of those highly touted 6m openings. The book says that the word hentenna comes from the Japanese ‘hen’ being fantastic or miraculous. I hope the proof of the pudding is in the eating…