If you cultivate an interest in building radios it’s likely that you’ll at some point make a simple receiver. Perhaps a regenerative receiver, or maybe a direct conversion design, it’ll take a couple ...

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 simple LED torch is driven by a 2-transistor blocking oscillator which steps up the voltage from a 1.5V cell. It relies on the inherent current limiting of the 150µH choke to protect the white ...