Found in a 1965 Electronic Design, this circuit makes it possible to select signals with an inverted phase using a relay and a unit gain stage.
Found in a magazine 73 for radio amateurs, this circuit has two settings, one for the interval and the...
This good quality amplifier found in a 1982 documentation has a traditional complementary output...
A low frequency divider can be made using common unijunction transistors as shown by the figure...