This selectivity multiplier circuit for 455 kHz IF receivers was found in American documentation from the 1980s. The circuit requires a symmetrical power supply.
The circuit below is found in the manuals of several manufacturers in the LM123 series of...
The integrated circuit used in this 70's project is unusual, being the critical element of an...
We found this circuit in Radio Electronics magazine from May 1967. The circuit has the tuned...