b. NT modem. Army and Marine AN/TSC-85As and Air Force AN/TSC-100As use the NT modem. It is
made up of three chassis assemblies, the MD-1131 modem, the MD-1132 communications unit, and the OX-64
(1) The MD-1131 modem contains a beacon demodulator, a 75 bp/s critical control circuit (CCC), and a
variable data rate 75 bp/s to 32 kb/s link communications circuit (LCC). This modem also contains all operator
(2) The MD-1132 communications unit contains three LGCs. These circuits provide the three links
required for hub operation.
(3) The OX-64 coder group, TRANSEC, 10-channel unit houses ten KGV-9 TRANSEC modules,
associated interface circuits, and the power supplies.
c. NNT modem. Army and Marine AN/TSC-93As, Air Force AN/TSC-94As, and selected satellite fixed
station gateway terminals use the NNT modem. It is made up of two chassis assemblies-the MD-1131 modem
and the OX-63 coder group.
(1) The MD-1131 modem is identical to the NT modem.
(2) The OX-63 coder group, TRANSEC, 4-channel unit is identical to the NCT modem.
LEARNING EVENT 7: DATA ENTRY
Data entry requirements for the operator of a multichannel TACSAT terminal AN/TSC-85B/93B consist of
information (data) extracted from the SAA by the CSPE and included in either the mission OPLAN or the
1. This information takes the form of-
Operating frequencies (may not apply until SAA is received).
Transmit power (may not apply until SAA is received).