Found in 1967 Raytheon documentation, this circuit uses a company coupler consisting of a lamp and an LDR. The transistor is according to the load current.
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...