This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time and the frequency is determined by the crystal. The circuit operates at voltages from 3 to 9 V.
Suitable for general use and alarms, this Hartley oscillator circuit from a 1960's Gernsback...
Found in a 90s Popular Electronics, it serves both TTL and CMOS logic. The injector can provide 10...
This filter with the operational 741 passes the frequency range between 300 Hz and 3,400 Hz. This...