Signals of up to a few tens of kilohertz can be generated by this circuit found in a European publication from the 1980s. Transistors admit equivalents and the unijunction can be 2N2646.
This is the basic configuration of a function generator with the 8038 integrated circuit (uncommon...
This filter for receiving audio in telegraphy was found in a magazine 73 for radio amateurs, in an...
This circuit amplifies VHF signals in the two-meter range and is very critical, especially...