This circuit, found in 1993 documentation, is the traditional relaxation oscillator configuration with unijunction transistor. The frequency depends on C and the resistance value R.
This amplifier with two transistors for analog instruments was found in a Raytheon publication from the...
Using a ceramic resonator, it is possible to vary the frequency between 4.9 MHz and 5 MHz. The...
This operational filter configuration was obtained in a 1980s publication. The calculation is made by the...