This circuit operates from 25 to 65 kHz depending on the transducer used and the settings. We found it in the Radio Electronics magazine of July 1985. The 9V to 12V power supply is not given.
This interesting comparator circuit was found in an old Motorola documentation. The integrated circuit...
This transistorized shift register was found in a 1970s RCA documentation. The used transistors can...
We present a commercial circuit for a small amplifier (CF-401) sold in Japan in the 1960s. The...