I'm interested that it doesn't mention the nonlinear junction detector, but I'm no spyhunter or anything and maybe that's an obsolete piece of equipment now. After all, there's certainly a lot more innocent transistors and diodes out in the world today than there were during the cold war. Also I'm not sure they're legal for just anybody to use since they vomit so much radio interference.
An interesting build:
http://67.225.133.110/~gbpprorg/mil/non/index.html