Found in Popular Electronics from the 90's, this tuned to infrared modulated receiver uses a PLL. The circuit has a signal strength indicator.
In this circuit we show how to configure the LM3914 as a bargraph or moving point, supplying 10...
We found this circuit in a documentation for 1977 American radio amateurs. The LM336 integrated circuit...
This modulator circuit is nothing more than an audio amplifier that serves to modulate amplitude...