4 ms·
There are lots of ways to homebrew variable capacitors. A sheet of glass and two pieces of scrap copper does well. I have a "crystal" radio (uses a modern diod
by ja27 15y ago
There are lots of ways to homebrew variable capacitors. A sheet of glass and two pieces of scrap copper does well.
I have a "crystal" radio (uses a modern diode) all built on a paper towel tube. The coil is wound on the tube like usual but at the other end of the tube there's also a layer of foil and a smaller tube with a layer of foil that slides inside that to make a variable capacitor.
- Craiggybear 15y agoGood VC advice. Also, I find that inserting a ferrite rod into the coil (or winding the coil around the ferrite rod to begin with) makes tuning much more effective (sharper) and makes the audio signal much stronger. A steel or iron 6" nail also works if you want to dispense with the ferrite rod.
- ul5255 15y agoI once found this site with lots of interesting projects: http://www.sparkbangbuzz.com/ http://www.sparkbangbuzz.com/