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 circuit is intended to reinforce old car radios, having been found in 1997. At that time,...
This oscillator found in Electronics Now of the 90s is of the Normally-Off type, being triggered...
This circuit was found in a Popular Electronics of the 90s. The operational amplifier admits...