Found in an 1868 Mullard documentation this circuit has a dynamic range of 10 Hz to 25,000 Hz. Modern equivalent transistors can be used.
Line voltage compensation (CB8816E) This circuit for the alternating current line (AC line) was...
September 2017 - IXYS Class X2 to 700 MOSFETs can now be purchased from Mouser Electronics....
Depending on the value of C1, this oscillator can produce signals of up to 1 MHz. For a capacitor of 10...