Just in case anyone needs all of the codec frequencies..
Here they are:
Col. Campbell/Dr. Naomi Miller: 140.85
Mei Ling: 140.96
Deepthroat: 140.48
Meryl: 140.15
Otacon: 141.12
Master Miller: 141.80
Nastasha: 141.52
"Who knows where thoughts come from? They just appear!" - Lucas, Empire Records