This circuit by Ferranti, in a 1967 publication, is intended for reading perforated tapes. The circuit uses transistors from the era that can be replaced by modern equivalents.
Using a 7400 we have a short-wave transmitter from 4 to 9 MHz, shown in the figure. The coil...
This handy instrument on the maker's bench that does not have a multimeter yet serves to test...
In the figure we have the way to implement the E (AND) function with two inputs, in the case of...