First day of vacation and I wanted to tune up my Kenwood Ham Radio. Its a great working hybrid transceiver. It has 3 Vacuum Tubes. The driver and a matched set of finals. It also has a heater switch so you can cool off the tubes if your just listening.
Whats an UnUn? Its a transformer used to match an unbalanced line to another unbalanced line of a different impedance. And A Balun is used to match a balanced line to an unbalanced line.
I put a long wire antenna along the back yard. My rig has an unbalanced output and my antenna choice was a single long wire, also an unbalanced termination so I made an UnUn to match the wire to the rig.
I would have preferred a balanced antenna but my back yard is about 3X longer than my front yard so if I ran a wire in opposite directions they would have been much shorter overall. I guess if I get bored I’ll try an inverted V. The conduit box option would be great for this.
I drove a 6 foot ground rod into the ground right next to a fence post and mounted the UnUn right above it on the post.
So far it seems to work pretty well. Tennessee contacts nice and clear. Next I’ll get back to the Arduino beacon projects. I had a working Hellscrieber beacon that needed a nice waterproof housing. I’ll probably use a plastic conduit box.
That might make a nice fox hunt rig too. I could hide it anywhere with just a piece of romex hanging down as the antenna. Most would overlook it as an old light box….
There’s nothing mysterious to it just a ferrite core and some wire.
How you connect the wires decides what it will be.
For the whole story on how to build one check these Instructables.
http://www.instructables.com/id/How-to-Make-a-Balun-Or-Unun/
http://www.instructables.com/id/Better-Balun-Boxes/