This circuit was found in old documentation, but the setting applies to any operational. Resistors and capacitors determine the frequency. For the indicated values the frequency is 10 kHz.
This circuit was found in a 1967 Raytheon manual. The transistors are from the time. Equivalent modern...
This circuit was published in a 1979 magazine, but it can still be easily assembled as the...
The circuit presented generates short pulses. This configuration was found in a publication from...