This commercial receiver for the mid-wave range of the 1960s was found in Japanese documentation at the time. The supply is 9 V, and the configuration is superheterodyne type.
This sonic, sound or vox switch uses common SCR and transistors can be BC548 or equivalent. The...
This circuit allows you to use a calculator as a timer by directly activating a sum key with...
This circuit is from the time when photos were revealed in darkrooms. We found it in a 1968...