Are you tired of listening to the BBC and Voice of America on your shortwave receiver? Do you want to hear something new and exciting? Than this book is for you.
Written during the peak of unusual radio communications, The Underground Frequency Guide covers "numbers stations" that intelligence agencies may use to communicate with agents, international diplomatic traffic, Air Force One's phone calls, and bootleg radio users... everyone from fishermen to guerilla military forces.
Oh, and did I mention that it's 100% legal to tune in in the United States?
The only problem with this book is that it has become just a bit outdated. Frequencies change on occasion, and some stations mentioned have been silenced, gone encryped, disappeared, or switched frequencies.
This book is a good background read, but don't expect all the infromation to remain accurate. For more recent information you can check websites like spynumbers.com.