With this circuit, signals in the range of 10 kHz to 150 kHz can be received at close to 4 MHz from a shortwave receiver. The circuit is from a 303 Circuits from the 90s.
We found this circuit in the National Semiconductor's Linear Applications Handbook of 1994. The...
This circuit activates a relay that has a lamp as a load. The circuit is from a Radio Electronics from...
This experimental 555 circuit sends signals in the medium wave band to a receiver a few meters away....