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.
Direct link to Oxford Shortwave Log channel
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.
Just added the HC-05 bluetooth module onto my FDM-DUO’s serial port, wow, pretty darn cool, using my Samsung android phone to control the radio with BLUEDUO. Took about an hour, start to finish to program the HC-05 using the Pi2 and soldering etc. but it works really well, very handy. The BLUEDUO app seems pretty stable too. Would be nice to have a + – tune button rather than using direct entry or clicking the waterfall though (as hard to tune accurately, that is my only bugbear of the app right now but I am sure that would be easy to implement.
Interesting video! That Elad FM Duo is a thing of beauty! Sure reminds me of the AOR 7030. Foot print must be similar.
Thanks Walt! Indeed, the FDM DUO is a beautiful piece of kit and I completely understand how the form-factor reminds you of the AOR 7030….another great receiver. Clint
I did, with some excellent results which will be uploaded to my youtube channel. Thanks for your comment.
With that environment and the 200m Beverage, try for South America. Hi!