Solar Frequency Standard (CB21951E)

This solar cell powered circuit generates a standard 100 kHz signal. The circuit is from a 1960 Gernsback documentation.

Negative Feedback Stage (CB6131E)
This circuit is from a 1967 US publication. The configuration can serve as a basis for designs...
Intermittent buzzer (CB20494E)
This two-tone buzzer can be powered by a solar panel. The circuit is from a 1991 documentation. The...
Tone Control Preamplifier (CB18561E)
This preamp with several inputs using germanium transistors from the time was found in Japanese...