This commercial radio with 3 earphone listening transistors was manufactured in Japan in the 1960s. The medium-wave circuit uses germanium transistors and is powered by a 9 V battery.
With a coil formed by 7 turns of 26 AWG wire this circuit operates in the 27 MHz range. But you...
The circuit shown is a commercial electronic voltmeter sold in Japan in the 1960s. The circuit is fully...
This amplifier for recording heads was found in a Radio Electronics from September 1963. The...