We found this receiver on a single chip in the 1976 Siemens integrated circuits manual. The circuit is of the super heterodyne type using ceramic filter in the IF.
This circuit is recommended for alarm systems since it has a good output stage. The circuit is...
) Suggested by Philips in a 1968 documentation this circuit has very high 10 ohm on-load voltage...
No information is given about the transformers in this circuit suggested by Motorola in a 1968...