Look at this Ham Radio: Gqrx is a software defined radio receiver powered by the GNU Radio SDR framework and the Qt graphical toolkit.

Look at this Ham Radio: receiver.

Consider a SDR (software designed radio) on this site, let your PC control the Radio parameters.

Consider GNU Radio as a great software option for Ham Radio.

Consider Amateur Radio Astronomy, also this site, and this NASA site.

Here is another great article on Very Weak Signal Reception with Small Magnetic Loop Antenna.

Inductive Coil Magnetometers vs SQUID

Here is a great article on

Microwave Horn Antenna Theory & Equations