Transistor gain meter (CB20522E)

This circuit was found in a publication in the 1950s, mainly applying to germanium transistors of the time.

12V x 220V Inverter with 555 II (CB1297E)
The critical component of this circuit is the transformar. We found it in an 1980s documentation....
100 MHz Optical Receiver (CB15957E)
This circuit was suggested by Motorola in its manual of components for optoelectronics (1987)...
Swimming Starter (CB26087E)
This circuit was found in the February 1999 issue of Electronics Now magazine. The circuit...