This is the right time to talk about what one can do during solar minimum.
A video, showing a radio amateur extending a long wire antenna and matching it with an external ATU that I stumbled upon just before Easter, reminded me that one of those matching units existed in my garage.
It’s a relic brought here from our previous home and never installed on this site, that was utilised in its previous life to match a vertical antenna consisting of the usual random wire and the equally rather usual – and poor – ground system. The poor ground system wasn’t the result of negligence, just a constraint imposed by the lack of extensive space and a lawn area to host the required amount of ground wire.
As the problem of restricted space has now been resolved, I thought it might be worth trying the same type of antenna but with a new, larger and more efficient, ground system. Despite the size increase I kept the whole system very light and, most importantly, very portable so that the whole antenna can quickly be removed when needed and then reinstalled almost instantly. Thinking of it, this configuration will be well suited to travel, including by air.
The new whole system now consists of a 12m pole and wire, the ATU, a set of 18 radials most of which measure about 10 metres, plus a choke on the coax feeder. The below image shows how the poor quality of the coax cable that I used to build the choke was compensated by the superior quality of the chosen core. If you plan to build a similar choke system, often colloquially described as “ugly balun”, please ensure that any fizzy leftover is removed before the vessel is utilised as the inductor’s core.
The antenna proved to be a success, able to perform well on 40m, 30m, 20m and 17m, offering numerous opportunities for long distance QSOs especially on 40m where on two occasions I engaged in lengthy Olivia MFSK QSOs with stations as far as Australia. I wonder how well it would have performed if I only managed to build it properly.
The take away story from this post is that this type of ground mounted antennas, which are either resonant 1/4 wave or some other random fraction of a wavelength, or longer than a wavelength, greatly benefit from a large radial system. They are relatively easy to install however if you are unable to use recycled materials can be quite expensive – think about the cost of 200 metres of reasonable quality insulated wire for all those radials. And of course, if space is a problem you may have to settle on a compromise between performance and ground wire. In fact, in cases where space is VERY restricted, you may want to look into 1/2 wave antennas instead.
M0ZZM 