Thursday, March 19, 2009

Antenna and More TBall

I wonder how many calories one burns putting up a high frequency (HF) antenna? Over the last couple of months, an amateur radio friend of mine helped me to put up my first HF antenna. We designed and built a multi-band fan dipole (pictured at left with the exception that my antenna does not have an 80 meter wire), which in my case is set up as an inverted-V (not like the picture at left).

First we put up the mast. That took an entire day, during which we pounded a stake into the ground, put a plumber's plastic "donut" over it, and then fitted a telescoping mast over the stake. We attached some metal L-bars (with pre-drilled holes) to the eaves, as well as an L-bar cross piece. We then attached the mast to the L-Bars via a U-bolt. Then it started raining and the entire project got put on hold for over a month.

Last week, we drilled a hole through the outside wall and ran approximately 50 feet of RG-8 coaxial cable, about 15 feet of it into the house. The cable was put into the room where my "ham shack" desk is located - the play room that I will be sharing with my son.

Today, at last, we started to build the antenna. First we measured out three sets of wires for different HF bands:

  • 10 meters (approximately 17 feet long, cut in half);
  • 20 meters (approximately 35 feet long, cut in half);
  • 40 meters (approximately 70 feet long, cut in half);

Next, we attached the wires to a center insulator, added some separators to keep each wire from interacting the others, and raised it up the mast. We attached some "eyes" to the eaves of the house at either end, in order to tie down the tail ends of the antenna.

The next step involved "tuning" the antenna, which involves making the wires shorter or longer to put it in the right band (a set of frequencies). This involved lowering and raising the antenna multiple times, carrying a ladder from one end of the house to the other to do that, and then raising and lowering the center at the mast. I'm sure I burned up several calories and also gained some upper body strength carrying that ladder around!

We had enough time to tune the 40 meter wire today, but the rest will have to wait until tomorrow. I had to pick the little on up from taekwondo practice and take him to his TBall game. More calories spent here, as I helped the coach in the outfield.

So, I didn't get much walking in today, but I did exercise! And then after I came home and cooked dinner, I sat down at my radio and made my first HF QSO on 40 meters, lower side band, to a station in North Carolina. How cool is that!? All the way across the country on my wire!

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