Awhile ago, my daughter and I built a crystal radio (see the crystal radio pages for more information if you’re interested). We decided to do a bit of an experiment with it and add a second coil attached to the antenna.

We used the same gauge magnet wire (the wire has a different color coating, but is the same size) for the new coil. We added a second tuning wiper for this coil and changed the wiring of the radio a bit, so that one tuner is wired to the ground and one to the antenna. Now one wiper can be used to tune the large coil and search for stations, while the second wiper can be used to fiddle with the antenna (that’s a technical term!). Using both wipers together seems to help pick up additional stations. There is one very strong station, however, that seems to drown out most other signals. It was for this reason that we tried the second antenna tuner. I think it helps a little, but not as much as I was hoping.

Also, my daughter and her friends wired in more earpieces, so they could all listen at the same time. It worked very well! At one point, they had three pieces wired in at once, although now there are only two.