This sophisticated remote field strength meter circuit was found in a 73 magazine for radio amateurs from the1990s. The circuit measures signals in the 1650 kHz range.
This circuit was obtained in an 1975 English publication. It is a voltage regulator circuit for...
In the figure we have an infrared receiver circuit using an operational 741. The circuit is an...
This circuit is suggested by National Semiconductor and makes use of the negative regulator LM2990...