Internal Freq's used by the Phone Compant (Blue Box) 1 = 700+900 2 = 700+1100 3 = 900+1100 4 = 700+1300 5 = 900+1300 6 = 1100+1300 7 = 700+1500 8 = 900+1500 9 = 1100+1500 0 = 1300+1500 Additional Signals required for Blue Box: KP = 1100+1700 (Key Pulse) ST = 1500+1700 (Start) Disconnect = 2600 All Freq's are in HZ. US Army Frequencies ------------------- 1 = 2100+2300 2 = 2300+2500 3 = 1900+2700 4 = 1900+2100 5 = 2500+2700 6 = 2300+2700 7 = 2100+2500 8 = 1900+2300 9 = 2100+2700 0 = 1900+2500 All Freqs are in HZ. US Air Force Frequencies ------------------------ 1 = 1020+1620 2 = 1020+1740 3 = 1020+1860 4 = 1140+1620 5 = 1140+1740 6 = 1140+1860 7 = 1260+1620 8 = 1260+1740 9 = 1260+1860 0 = 1380+1740