This receiver was found in a 1924 book by Gernsback. The circuit uses three tubes and is powered by 3 batteries of different voltages, common at the time.
This low-pass filter was found in an American publication from the 80's. The circuit uses an...
ROHM Numeric Displays ROHM sells through Mouser Electronics its common anode and cathode numerical...
This circuit was found in Linear Technology documentation from the 90's. The circuit uses...