Sometimes, it is useful to transmit a low-power radio signal to create a beacon, to send a signal carrier to a near receiver, to transmit in QRP or QRPP mode, and so on. The circuit shown here is very ...

This circuit is essentially an amplified crystal set. The inductor could be a standard AM radio ferrite rod antenna while the tuning capacitor is a variable plastic dielectric gang, intended for small ...

A staple of starting off in electronics ion years past was the crystal set radio, an extremely simple AM radio receiver with little more than a tuned circuit and a point contact diode as its ...

You probably have needed to match impedances and levels from time to time. Perhaps you want to connect a consumer computer’s sound card to your console; or you need to lower a balanced output level to ...