Did a little checking...
Geoff Fors actually has a section posted for odd radios, and he mentions the "Aerotron" brand used by NC. Here's a link to his site:
http://www.wb6nvh.com/Aerotron/Aeromeg.htm
Radio reference has a guy who probably still works for NC, and he seems to have a wealth of knowledge about their equipment. Here is a link to the thread:
http://forums.radioreference.com/nor...al-trafic.html
I'd join there and PM him.