We had found this circuit in a January 1961 Radio Electronics Magazine. Using it is possible to take measures from the gain of transistor with a common a multimeter.
This oscillator uses a general-purpose transistor that can have BC548, BF494 or 2N2222 equivalents and...
Offset Adjustment on an Amplifier with the LM139 (CB14245E) In the figure we have the way of...
The critical components of this 1978 circuit are transformers, which, hopefully, can be obtained from...