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 was found in a 1967 American documentation. The switching diode (tunnel) used is an...
This circuit was found in a 1975 documentation. Operational amplifiers must have a symmetrical source and...
The diagram shown was found in a 1975 active filter manual. The tuned frequency range depends on...