The integrated circuit used in this trigger is uncommon today. We found it in a documentation from the 70s. The circuit operates with signals up to 50 kHz.
This circuit is an excellent shield for microcontrollers and was found in the October 1987 Radio...
We found this circuit in a 1981 publication, when it was still possible to find 22.5 V batteries (used...
This grid-dip meter was found in a 1956 documentation from Sylvania. It can be implemented with...