the contacts must be treated with a non-return element to prevent sparking on the contacts

Producing a decent signal in a race on the lower bands is an experience of the final stage and the antenna. A forty-meter vertical will produce a signal that few have, perhaps only the fanatics, which invest hundreds of thousands in masts.

The idea of ​​using balloons to pull out a vertical antenna is not new. It can be used for one-time events such as the CQ WW Contest, provided that there will be no wind or only weak wind.
This idea was dusted off by this, that you can also buy the necessary helium and balloons here. We can choose either a larger number of smaller balloons (10 – 15) and a small helium bomb or a large advertising balloon. The company could also lend you these, which has purchased it for advertising purposes.

Because of that, that it is a temporary antenna, an antenna seems to be the most suitable lambda/2, which saves us the effort of burying the radials. This antenna has a high impedance in the heel, so a transmatch will be required to connect to coax. m of the telescope will be the impedance of the emitter about<2 is about 80kHz in the 80m band.

In the place of the heel, we drive a grounding rod into the ground, which will anchor the antenna at the same time. Considering the weight, we choose a thinner wire, CuL with primer will suffice 0,5 - 0,7 mm. In addition, we will need two insulators (Attention, because there is a high impedance in the heel, there will also be high voltage!) a nylon fishing line. It winds along the radiator and its task is to catch the antenna if the copper radiator breaks. Never release the antenna without this fuse!

The beam is about 40m high, fine-tuning can be done using GDO. Due to the fact, that the antenna will never be completely stable, PSV will also change. It is advisable to set the antenna to a lower frequency, because the wind will push it down, which will shorten it. It is only possible to build such a high antenna at a sufficient distance from the trees, of HV masts and other dwellings.

In case, that the meteorological situation will worsen (storm, vietor), we pull down the antenna. The wire emitter coils very well on the drum of the garden hose, even a bucket in need. By rolling it on an elbow or a board, we would deform the copper conductor and we would probably end up with an out-of-shape ball.

Literature:
[1] Two contributions to the antenna issue, RZ 9/1985
[2] http://www.hard-core-dx.com/nordicdx/antenna/special/baloon.html