Small, practical antenna at 160m…

Small, light, simple, practical…
This is how he imagined his 160m antenna Alan, G4ERZ. To what extent he succeeded, judge for yourself.

He divided the insulated wire with a length of 42.6 m into two parts and simply wound the first 21.3 m on a pipe made of insulator. In his case it was fiberglass, however, we can also try e.g. Major tube, possibly an installation pipe with the trade name Hostalen. Diameter and length depend on our conditions, but please keep in mind, that the longer the pipe, t.j. the wire will be wound on a longer length, this will make our antenna have more favorable radiation parameters. So we will not try to wind this half of the wire unnecessarily on a 50 cm pin, when we can anchor safely on the roof of our house, e.g. 5m length. In both cases, this section of the antenna will have a very adverse effect on the radiation parameters, above all, the efficiency of the entire system, but in the case of a 5m tube, our antenna will be considerably more usable. I recommend keeping the gaps between the threads the same width, such as the diameter of the coiled wire.
The second part of the length of 42.6m is then stretched diagonally from the roof towards the ground like this, so that it ends approximately at a height of 3-4m above the ground. It should perform the function of capacitive load and its position is not critical.
The system is powered by a coaxial cable 50 ohms in the heel, vertically placed winding parts, where we must not forget a good counterbalance. In this case it will apply, the more, the better. Improving the ground system for such an antenna will clearly lead to an improvement in the behavior of the entire system, which in this case has both vertical and horizontal polarization and must be tuned into resonance as a whole.
According to Alan, the bandwidth is about 30kHz from resonance for usable SWR. Alan experimented with both the antenna and the ground system and came up with a common knowledge : The resulting quality or. function of the entire antenna. He himself used two 42m long raised ones, tuned radials. We will do it simply like this, that we tune two radials against each other into resonance at the desired frequency as if it were a dipole lying low above the ground. Then we connect them and connect this point at the antenna feed point to the cold end of the power cable…

This is of course a replacement antenna and it won't be a miracle on the band, but if you only have a few meters of free space around you, then this antenna will get you to 160m. It depends only on you, how far you will win with the ground system, which doesn't have to be that big. In an emergency, we can stick to the rule “we prefer to bury 40x15m long rather than 1x80m long radial.

73, Petr OK1RP