This commercial radio for the AM band was sold in Japan in the 1960s. The circuit has an IF of 455 kHz and is powered by batteries. The push-pull output gives a good audio power.
This other high stability thermocouple amplifier uses an 80's operating. The circuit can be used...
The mains cables work as antennas. We can take advantage of them with this circuit that consists of a...
This circuit was found in an American magazine in 1976. It doubles the frequency of TTL signals in the...