We found this ladder-shaped signal generator circuit in Radio Electronics magazine from August 1966. The circuit uses a unijunction transistor as its base.
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...