This is a Japanese commercial radio from the 60s. The superheterodyne circuit of 7 transistors for medium waves has 200mW of output when powered by 4 common batteries.
This simple MW radio does not need an external antenna to pick up local stations. It was found in a...
This is a typical ohmmeter circuit with 50 uA analog instrument. The circuit was found in Radio...
This very simple circuit turns on an LED when an object interrupts the light that falls on the...