from outer space
with a wok
explains how to use a wok as a rudimentary radio telescope. I used a small
headphone amplifier. You could try using a guitar amp, although I've not tried using one myself. The diode and socket are very cheap - and available from most electronics
suppliers (eg, Maplins).
Note - all electrical work involves risks. Check out the health and safety implications. Also, what I did worked fine with my equipment, but you plug things into your own at your own risk!
1 steel wok
Amplifier (see above)
lead (shielded lead with two 1/4" jack plugs)
1/4" jack socket (mono)
diode (OA91 or equiv.)
Connect the two ends of the diode to two of the terminals on the jack socket - there are usually 4 on a jack socket. Make sure you don't select the two that are switched off when the plug is inserted (obvious when you look at it).
Make sure that the connections are mechanically sound - solder them if you know how, but remeber to hold the wire between the joint and the diode with pliers, to stop the heat reaching the diode.
Plug one end of the lead into the socket, and the other end into the amp.
Hold up the wok to face the sun (CAUTION: don't look directly at the sun). Move the socket with the diode on it back and forth just above the surface of the wok. You should find a spot where you hear a low scuffling sound as you move the diode. This is caused by radio waves transmitted from the sun. Turn the wok and diode round, away from the sun, and the sound disappears.