Sky Hook

My next problem is how to get an antenna up a bit higher than just lying on the roof.

Now I am not a natural mountaineer, and I am not going to go clambering on the roof or shinning up chimneys; I have a bit too much metalwork in my legs for doing that. But anyway, at the moment I am thinking about simple wire antennas so all I really need is a convenient sky hook to attach wires to.

I found some 2m lengths of steel tube at the local hardware shop, which was useful as they would fit in the car. They had a number of diameters so 4 rods of 25mm, 22mm, 18mm, 12mm could be fitted inside each other, sliding about 20 cm of the smaller tube inside the larger, and drilling through for a couple of bolts. This way I had a pole of about 7 meters. I attached a pulley to the small end and put a rope through it. I am hoping this will enable me to haul up some wires when I know what I want to try.

Next, I got a 1m length of 30mm tube and with the aid of a few brackets and bolts screwed this to the wall of an out-house. Now I could drop the 7m pole in (with the aid of a friend), tighten it up and admire my new skyhook.

I took the precaution of adding a few guy strings as it can get pretty windy here, as there is not much between us and the Atlantic ocean 60km or so to the west, apart from some medium sized hills.

I am also worrying about lightning, so decided to attach a sort of "lazy" earth. I ran an earth wire from the bottom of the pole along the ground for about 10m (without insulation) and buried it a little. This is mainly to provide a leakage path for static electricity to ground and might help prevent lightning strikes. I did not want to wire it to the outdoor mains earth as the wiring is rather low grade and I think a real strike back into the house wiring might not be so good.

This is still pretty much an experiment to see how this works out. The guy ropes are basically plastic string of unknown material, so I expect the sun will have a disastrous effect. Meanwhile the general springiness of the construction should help it withstand the weather for a few months by flexing rather than breaking. After that, I will have a better idea of how to make something more permanent, and whether this location for the upright is going to be okay, both cosmetically and performance-wise. This corner of our terrace is at the edge of big drop to the west, maybe 20m, so this should help with take-off angle even though the maximum height with this arrangement is only about 9m above the ground level on the terrace.