Sometimes a summit offers little space to deploy an antenna. Either because there isn’t much room or because there are many people at the top – or both. Then an antenna with a small footprint is required.
Some time ago I had a S2S-QSO with N1ZF. In the following e-mail contact we exchanged information and photos about the antennas used for this QSO. This is when I became aware of the „Random Wire Antenna“ that Paul had successfully used. It consists of a 12.8 metre long wire as radiating element and an equally long ground radial. Matching is done with the KX3’s internal ATU. Since the ATU cannot match any impedance, it is important to choose a wire length that is not a multiple of half a wavelength. This way the „odd“ length of 12.8 meters emerges.
A delta loop antenna – especially for the 40 metre band – is not exactly suitable for SOTA. It is huge and requires a lot of space. Furthermore the set up is time-consuming. Nevertheless I’d like to show this design here because:
During sunspot minimum 40 m still offers the opportunity to work a lot of DX.
The delta loop provides the required take off angle to work the DX.
Sometimes space (and time) don’t matter.
It’s fun building it 😉
A possible application could be intercontinental S2S events.
Here is the Link to the 20 metre version of the delta loop. During our DX-pedition (Link) to the Principality of Liechtenstein in Sept. 2013. DL4AAE worked hundreds of JA’s on 20 metres with this antenna and 100 W output power.
Recently I came across an article from Andrew, VK1AD, in which he describes a QRP L- tuner for 3.5 MHz to 52 MHz. It can be found here.
Andrew’s article is based on an essay by Peter, VK3YE, published in VK’s Amateur Radio magazine, Edition 5, May 2017.
I really wanted to try this easy to build L- tuner, because I thought it might perform even better than my EFHW- transformers (UnUns) and the EFHW- dipole I’m currently using for my SOTA activations.