This high voltage source, found in 90’s Popular Electronics, can reach tens of thousands of volts. The Q2 transistor must have an excellent heat sink and the 9 V source is high 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...