FLEXCOMM
II
C-5000 (Non-Digital)
Installation Manual
150-1355-000 Rev. M
CONFIDENTIAL AND PROPRIETARY TO COBHAM
Page 67
Pin(s) - Signal Name (Continued)
36 - EXT CIPHER ACTIVE
For cipher on/off switching using an external switch this pin, when grounded, will
automatically enable external encryption. If left open (unconnected) the operator
can select cipher Tx Mode by pressing the C-5000 “PVT” button.
3, 4 - XMT AUDIO IN HI/COMMON
This pair provides a voice band input to the transmitter(s) as selected by the
crew. Typical use is with external encryption equipment in which the mic input to
the C-5000 is routed out to the encryption unit and when the encryption unit is
not active, the mic input (voice band) is returned to this port for normal voice
transmit. Standard levels are 0.9 Vrms into 600
, although A2R160 and A2JP3
provide adjustment range of approximately 40 mV (150
) to 5.4 V (600
).
27 - AUX AUDIO IN HI
This port provides an auxiliary input to the headset audio amplifiers (primary and
secondary). It is not switched and all inputs to this port will appear at the
headset(s). Typical use is alert tones, progress tones, medical telemetry
equipment like Doppler Monitors, etc. Typical input level of 0.5 Vrms (5k Ohm)
will yield standard audio although A2R102 on the system interface board
provides an adjustment range of 0.33 to 7.75 Vrms.
35 - PLAIN/CIPHER SEL
This output provides control signals to external equipment for activating
encryption equipment. For normal operation, this output is an open circuit. An
active pull to ground is provided for encryption active.
12 - CIPHER/PLAIN SEL
This output is similar to Plain/Cipher, but is opposite polarity and provides a
ground for normal operation.
38 - RCV’NG EXT ENCRYP TEXT
This input, when grounded, indicates to the C-5000 computer that the external
encryption equipment at the system interface is receiving properly decoded and
encrypted text.
19 - XMT’NG EXT ENCRYP TEXT
When grounded, this input indicates to the C-5000 computer that the external
encryption equipment is active and is providing cipher text for wideband
modulation to the crew selected transmitter.