We don’t know who the [amgworkshop] wanted to listen in on, but they apparently went searching for a small FM wireless transmitter. There’s plenty of circuits around, but they wanted something smaller ...

For those who enjoy building radio projects, you may have noticed that variable capacitors are not as available as they once were. There was a time when all radio receivers contained at least one, but ...

[QRP Gaijin] likes to build regenerative receivers. If you’ve ever built a serious one, you know there are (at least) two problems: One is you need a variable capacitor (hard to find these days). The ...

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 ...