AMPLIFIED CRYSTAL RADIO
Original source:
My construction.
Description:
An improved crystal radio with a two-stage audio amplifier. The 2N3904 (or any other general-purpose NPN) acts as a preamplifier while the LM386 boosts the signal high enough to drive low impedance Walkman headphones or perhaps even a small speaker.
Problems:
The same rules that we've already been through at the previous page apply here.
Possible uses:
Make a real AM receiver! With a decent antenna and good ground you should be able to catch a station or two. You might also experiment with different coils for other band. A 12-turn air core coil 5mm in diameter should get you somewhere between 5 and 15Mhz, for example.
