What Happened to Varactor Diodes? The Diodes That Replaced Moving Plates
Fallen America FM
11,326 views
For decades, tuning a radio or television meant physically moving metal inside the machine.
Then engineers developed a tiny diode that could change its capacitance with nothing more than voltage. No rotating plates. No mechanical motion. In theory, it could make tuning quieter, simpler, and completely electronic.
But the varactor diode was far from perfect. Early versions brought their own limitations, and even as electronics moved toward push buttons, remote controls, and digital frequency selection, the old mechanical tuner refused to disappear overnight.
What happened next changed not only how radios and televisions were tuned, but where this unusual little diode would eventually find its place.
This is the forgotten story of the varactor diode — the component that helped turn tuning from a mechanical motion into an electrical command.
#VaractorDiode #RadioTuning #VintageElectronics
9 Comments
This is a very detailed discussion of a complex subject, much of it is tarnished by profound mis-pronouncations. Ron W4BIN
What Happened to Varactor Diodes? The Diodes That Replaced Moving Plates
Fallen America FM
11,326 views
For decades, tuning a radio or television meant physically moving metal inside the machine.
Then engineers developed a tiny diode that could change its capacitance with nothing more than voltage. No rotating plates. No mechanical motion. In theory, it could make tuning quieter, simpler, and completely electronic.
But the varactor diode was far from perfect. Early versions brought their own limitations, and even as electronics moved toward push buttons, remote controls, and digital frequency selection, the old mechanical tuner refused to disappear overnight.
What happened next changed not only how radios and televisions were tuned, but where this unusual little diode would eventually find its place.
This is the forgotten story of the varactor diode — the component that helped turn tuning from a mechanical motion into an electrical command.
#VaractorDiode #RadioTuning #VintageElectronics
In analog and mixed signal PLL, the varactor is used in the Voltage Controlled Oscillator (VCO).
The Q of the varactor also plays a part in the PLL or is completely eliminated via digital to analog converter correcting the loop.