We found this micro amplifier in a technical documentation from National Semiconductor. The circuit can be used on an experimental phone, being powered even by alternative power sources.
Found in a 1960 Sylvania manual, this circuit can be implemented with a modern equivalent...
This configuration, already presented in other points of this section and website, is of a...
We found this precise crystal oscillator for the 144 MHz band, depending on the crystal used. The...