This 1969 circuit uses a 117 V filament tube powered directly by the power grid. The original circuit makes use of a charcoal microphone, a common component at the time.
The previously mentioned versions of monostable multivibrators in this section are not...
We found this circuit in a documentation from the 50's. The transistors are germanium types. The...
This simple AM transmitter for very small ranges uses in the original version of the 1970s, a...