This circuit was found in an American magazine 73 for radio amateurs of the 80s. It is an automatic transmission circuit for telegraphy. The circuit is TTL.
This circuit, which uses only common transistors, was obtained from a 1988 publication, but can be...
The integrated circuit used in this filter is not very common today, but the configuration can be implemented...
Published in Radio Electronics magazine in March 1963, this circuit uses 4 transistors of the...