This circuit for signals up to 30 MHz can improve your reception in the medium and short-wave band. We found it in the Radio Electronics magazine of February 1989.
This 1965 Philips circuit uses transistors from the era. Modern equivalent components can be used....
Linear Technology (www.linear.com) has in its component line the LT3518, recently launched, which...
This circuit is used in communications receivers to silence noise that occurs in poor signal...