This circuit was found in a Motorola documentation from 1975. Modern equivalent transistors such as the BF245 can be used. The circuit is powered by 9 V voltage from cells or batteries.
Found in a 1968 EEE, this circuit accepts frequencies from 1 to 1000 Hz and control voltages from 0.1 to...
This circuit has appeared several times on this site in different applications. This is from 1997...
This setting appears other times in this section from other sources. This is from an 80's American...