Placed near a common receiver, this oscillator is intended to generate a beating signal to receive RTTY or SSB communications. The circuit is from old telecommunications documentation.
This ultra-simple 9 V power source was obtained in an Argentine publication of the 1970s, but it...
We found this filter in the 1990 Motorola Linear Databook, but it can be implemented with other...
The AC125 transistor is an ancient germanium type widely used in audio stages as a preamplifier. In the...