This filter for receiving audio in telegraphy was found in a magazine 73 for radio amateurs, in an edition of the 80s. The circuit is tuned to 700 Hz and has a 200 Hz bandpass.
This low drift or offset circuit is from an 80's documentation. The configuration can be made with...
This circuit rectifies low voltage sinusoidal signals for measurement purposes, as the circuit is of low...
Indicated for vinyl media recovery, this circuit is from the 80's, having been found in an...