Varactor

Some articles on varactor, varactors:

Tuner (radio) - Electronic Tuner
... Later electronic types utilized the varactor diode as a voltage controlled capacitance in the tuned circuit, to receive a number of preset voltages from the rack of buttons tuning the device instantly to local ... The electronic button rack controlling the new electronic varactor tuner was popular in television sets of the 1970s and 1980s ... Modern electronic tuners also use varactor diodes as the actual tuning elements, but the voltages which change their capacitance are obtained from a digital to analog converter (DAC) driven by a ...
Variable-frequency Oscillator - Analog VFO - Varactor
... See varactor and voltage controlled oscillator ... The varactor bias voltage may be generated in a number of ways and there may need to be no significant moving parts in the final design ... Varactors have a number of disadvantages including temperature drift and aging, electronic noise, low Q factor and non-linearity ...