Short Wave/Medium Wave Loop Antenna Frame - Window Mounted by Stonehedge1

Last crawled date: 3 years, 4 months ago

Homebrew SW/MW Loop Antenna Frame
Hi. This is an antenna frame for constructing a simple but extremely effective antenna for listening to Short Wave or Medium Wave signals (depending on how many coils you wind).
I have designed this to be easily mountable using 20mm pipe clips. You can also use 20mm aquarium heater clips to easily stick to your window.
There is a hole for a standard SO239 hole mounted female connector (16mm hole size). If anybody would like to use a different connector or mounting method please feel free to remix. I'd also be happy to make changes for people myself if I have enough time. Just leave your request in the comments.
My starting point was 100 turns of 0.4mm polyster coated copper wire (roughly 60m of wire). This has given me excellent results on the 31m band (~9500Khz). I have been able to listen to stations >7000mi away from me in my 2nd floor central London apartment. This config doesn't work very well for MW though...it's up to you to figure out how many coils you need for that!
Tips:
When winding the coils, start by threading the end of the wire through one hole to where the connector is and then block one of the two wire holes leading to the connector with a cocktail stick to make sure there is room to thread the final strand through.
I find that a small diamond file is ideal for stripping polyester coating for soldering. Sandpaper works well too.
Its not essential, but I like to use a dab of hot glue to keep the coils in place once winding is complete. Its a bit of overkill as the wire stays in place well by itself but I like belt and braces :D
Printing is easy. No supports required. PLA works fine but if you are going to leave this antenna in sunlight for any period of time I would recommend using PETG or ABS.
SUGGESTIONS!
If anybody has any suggestions on modifying this to be tunable, please leave a comment. I don't actually know how to fit a variable capacitor to this as I am totally new to SW listening!