This peak detector has a memory to prolong the response. The circuit is from American documentation from the 1980s. The supply does not have to be symmetrical.
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...