This circuit for UHF between 800 and 1 000 MHz was found in an American documentation from the 90's. The integrated circuit is from that time, uncommon today.
This circuit, from a publication from the 1970s, can be implemented with more modern transistors and 6 or...
This plug-in control was found in General Electric documentation from the 1970s. The SCR can be...
This circuit is of an old Argentine magazine of the 70's. The difficulty for its assembly is in...