Here is a simple circuit for a one transistor Audion type radio powered by a 1.5 V battery. It employs a set of standard low-impedance headphones with the headphone socket wired so that the two sides ...

When a Hackaday article proclaims that its subject is a book you should read, you might imagine that we would be talking of a seminal text known only by its authors’ names. Horowitz and Hill, perhaps, ...

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 ...

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 ...