This an old commercial receiver found in a year 1958 magazine. The circuit uses some transformer available that timer and the transistors are germanium types. The circuit is intended to receive MW stations.
In the figure we have a very sensitive touch switch circuit. A touch of the sensor causes the...
This timer counts down the times until, at the end, it activates a relay. The programming time is...
This filter is from a 1977 publication. The circuit employs three 741 or other operational...