Software Defined Radios (SDR)

There are a number of inexpensive (around $20) software defined radios which are built around chips used in as television tuners.  One of the chips is the RTL2832U and there are numerous USB dongles which are built with this and tune from 100kHz to 1.9GHz!

For more information, check out:  https://www.rtl-sdr.com/about-rtl-sdr/