This circuit was found in a Signetics documentation from the 1980s. The integrated is a PLL and the SCR is a general purpose type The pitch frequency is given by R1 and C1 as formula next to the diagram.
This circuit generates pulses at a frequency that can be adjusted by a potentiometer. The circuit is...
In this application we show how to get tuning from 0 V to an LM350 regulator IC. The setting also...
The circuit presented is a simple MW tuner that can be plugged into the input of any audio...