This is a two-input audio switching circuit. The operational can be of any type and more entries can be added. The power supply must be symmetrical.
This is the receiver for the transmitter suggested in CIR13081. The configuration is old, and...
This circuit has a frequency control. We found it in a Radio Electronics from January 1965. The...
This circuit was found in an old American magazine for radio amateurs. The circuit is based on a...