This an old commercial receiver found in a year 1958 magazine. The circuit uses some transformer available that timer and the transistors are germanium types. The circuit is intended to receive MW stations.
This circuit is suitable for modulating AM transmitters. The circuit is from a 1977 radio amateur...
This double tone generator uses a specific integrated circuit, having been found in a 1977 CMOS...
This is a simple 1-digit voltmeter circuit using voltage comparators. It was found in a 2004...