For only $10, apparently it is possible to build this small short-wave radio receiver, which operates in the 5-15 MHz range.
The receiver is comprised of only 3 transistors, and about 30 components in total, some of which are coils which require winding. wooo-hoo - we love winding coils around the end of a drill-bit :)
All transistors are 2N2222 [PDF Datasheet] (also known as the PN2222), which is a very common Bipolar Junction NPN-type RF transistor. According to the description of the circuit, total current consumption is less than 10mA (milliAmps) from as 9V DC battery, so it's pretty easy to find a power source.
The circuit can operate with either a whip-type antenna, or an external antenna, which will obviously provide better results (although requires decoupling).
- Radio Receiver Circuits
- Radio Receiver Circuit
- Receiver Circuit