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.
We found this circuit in the November 1992 Radio Electronics magazine. It works with both...
This circuit came out in a Popular Electronics from December 1995. It is a Wien bridge...
The transistors of this filter found in a 1993 publication can be BF245 or MPF102. The filter...