If you enjoy building radio projects you may have noticed something slightly worrying over the last few years in your component supply. Variable capacitors are no longer as plentiful as they used to ...

Although the ubiquitous LM386 IC was designed to be used as an audio amplifier, it has a number of undocumented characteristics that can be exploited to create simple radio receiver circuits that ...

Any PN junction diode can be used as a variable capacitor in reverse biased mode, as well as in the forward biased mode before the knee voltage. The capacitance is usually very small as the junction ...

Amateur Radio as a hobby has a long history of encouraging experimentation using whatever one might have on hand. When [Tom Essenpreis] wanted to use his 14 MHz antenna outside of its designed ...