Summer antenna maintenance

Every summer I try to spend some time upgrading my station and antennas. This year was a bit more difficult, due to my medical condition. Besides, I had a difficult time coming up with things to improve. I’d pretty much maximized what can be done from this QTH, given the restrictions of bring in military housing.

Since it’s been three years, I spent most of the time renewing all the guy ropes and other lines that keep the antennas in the air. I use 550 para cord everywhere. It is strong, cheap, and seems to resist UV quite well from my experience. All lines got renewed – for the Spiderbeam and 80/160m vertical. Additionally, I renewed the ratchet straps on the roof that helps to lock the Spiderbeam mast in place. The three-year-old nylon straps were faded, and the ratchets themselves had turned into large hunks of rust.

One upgrade I did accomplish was to build a new 6m yagi, based on G0KSC’s excellent loop fed yagi designs. I chose his 6.8m, 6el design and tweaked the dimensions with EZNEC. Justin’s design uses single piece elements, which requires tubing lengths too long to easily ship to Guam. I essentially modified the design to use tapered elements, and purchased the aluminum from DX Engineering.

For insulators, I used fiberglass blocks cut from 1/4″ GPO3 sheets available at McMaster-Carr. The material is inexpensive and is easy to work with (cut and drill).

The new 6m yagi brought some excitement over the summer. I worked two stations in the Ukraine, a station in Israel, W7GJ on EME (Earth Moon Earth), and even copied CT1HZE in Portugal – a very long haul on 6m.

KH2/N2NL antenna farm, summer 2013
Another view of the antenna farm
New 6m yagi, based on G0KSC’s loop fed yagi designs
New 40/30m vertical (utilizing the existing radials)
Closer look at the feed point of the 40/30m vertical
New 6m yagi, built using the skeleton of a Cushcraft 50-5 and some new aluminum tubing from DX Engineering
close-up of the feed point
One of the element insulators, utilizing the old cushcraft element-to-boom clamp and a piece of 1/4″ fiberglass
View of the loop feed and matching balun which runs parallel with the boom