Using a varactor or varicap, this 1969 Electronics World circuit has a modulation range from 75 kHz to 52 MHz. Modern equivalent components can be used.
The integrated circuit used in this configuration for noise reduction on FM radios is not common...
The presented circuit provides an output voltage proportional to the input current, according to...
The low-pass filter shown in the figure uses two operational amplifiers with JFET at the input to...