This audio oscillator is from a 1957 Raytheon publication. The tone generated depends on C2 and C2 and the handset must be high-impedance magnetic. Equivalent transistors can be tested.
This circuit was found in Intersil's 1992 documentation consisting of a test for ADc0801 and...
This 60's shield or driver employs germanium transistors. The circuit is from a 1960 Gernsback...
The circuit shown in the figure on the right can be used on a data transfer bus with the use of an...