As some of the subscribers to Oxford Shortwave Log will know, I’ve been talking about building a battery pack for my Elad FDM DUO to take it out on a DXpedition. Finally, I found the time to quickly do just that with some parts that cost less than £10 – as the video below demonstrates in more detail. The FDM DUO input voltage is stated as 13.8V and although 12V would probably have been sufficient, a couple of very cheap battery cases later, 9 x 1.5V ‘C’ cells and about 20 minutes of somewhat unpractised soldering did the trick. I have also put together a 200 metre longwire antenna, deployable from a large spool, with a termination connector to add resistor grounding for a Beverage Antenna configuration, should I wish to do so in the future. I used two spools of 100 metre equipment cable, soldered together and protected with heat-shrink.
Regular viewers of my youtube channel will know that I spend much of my shortwave listening time out in an Oxfordshire wood where QRM is negligable and Tropical Band stations can be heard with, at times, unprecidented signal-to-noise. This is the first time I’ve used a longwire greater than 100 metres in length, however, to be resonant at two wavelengths for 90 metres and 3 wavelengths for 60 metres was the objective. I hope the already fine Tropical Band listening to be had out in the Oxfordshire countryside will improve further.