This circuit aims to increase the selectivity of receivers whose FI is 455 kHz. The circuit is from 1975 documentation. The transistors can be the modern BF494 equivalents.
This circuit was obtained from a Hands-On Electronics, an American magazine from January 1987. The...
This receiver for listening to the TR-23 phone was manufactured in Japan in the 1960s. The circuit is...
This astable multivibrator with an operational one at the time was found in the National...