Make:

A 'regular' low impedance earphone will not work in this circuit. Find a high impedance [ 2000 ohm] or a crystal earphone . see link:
http://www.midnightscience.com/catalog5.html

To change the station, or tune it you'll need a variable resistor. Here's a way I found to make one from a sheet of paper, pencil and 2 paperclips. The black rectangle needs to be very dark.

http://img187.imageshack.us/my.php?image=0915014211gs2.jpg
^-- taken with my phone.. so bear with the quality.

Move the paperclip to tune the radio.

arvash, I'm pretty sure you mean a variable capacitor
thats what most radios use for tuning

@mikiex ahhh I see.. if that's true than my variable resistor shouldn't work >>... You can make a variable capacitor by using a book and 2 sheets of aluminum foil. Seperate the two sheets of aluminum foil by a page or so. Press the book together for higher capacitance, release a bit for lower capacitance. I think I get why you can't use a variable resistor here.

must some telepathy going on. I was just thinking about the razor blade radio I made 45 years ago. You could buy blued razor blades then. it worked quite well considering

texbrandt

We used to do something like this in 1960's.Worth doing this again to show the kids with iPod!

Hi, I want to try to make it but can I use a razor like this one
http://www.sxc.hu/pic/m/b/br/brokenarts/435178_razor_blade.jpg

and thanx

Much easier to wind the magnetic wire with hand drill. Mount a dowel on the bit and toilet tube on the dowel and wind away. A lot less tedious and no wild windings like with that drill press in the video. If you can't heat up a razor to blue it you can always try a rusty razor,(just don't nick yourself with it... lock-jaw and all that) if I'm not mistaken its the oxidation of the metal that allows the process to work.

ggfffffffffff

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