This circuit is from an ancient American documentation. The transistors are of the time and the circuit uses a special sensor to detect the trigger point to produce spark plugs.
In the figure we have a Texas Instruments circuit for TTL interfacing using discrete transistors. The two...
This circuit was found in Radio Electronics magazine from June 1963. The range is small and the...
The project presented in a 2009 documentation is intended for radio amateurs operating in the...