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 was obtained in a magazine for radio amateurs 73 of the 90s. The circuit is based on...
This input stage has unit gain but a high input impedance and low output impedance. The circuit is...
May 2016 - It can be obtained from Mouser Electronics new display 1092 from VDC. The new LED...