TM 11-5821-333-30
4-5. CONTROL SIGNALS. Continued
SIGNAL
DESCRIPTION
PT/CT IN
PT/CT OUT
PT DIG CLK
PTT
PTT IN
PTTO
PTT OUT
X-MODE CONT
Open = Audio or standby mode
Gnd = Digital mode
NO CODE DET
Logic 1 = No code detected; pulsed
approximately every 1 msec in plain
text, latched in cipher text
Logic 0 = Code detected or standby; in pulsed
mode, signal is extremely short dura-
tion
+28 V = Z-AHP selects plain text
Open = Z-AHP selects cipher text
Gnd = DRA overrides plain-text selection
Open = KY-58 in plain text
Gnd = KY-58 in cipher text
16 kHz clock; in rcv mode is from bit sync
module; in xmt mode clock is from FSK detector
Logic 0 = Transmit mode
Logic 1 = Otherwise
Gnd = Transmit mode
Open = Otherwise
or self-test
Gnd = Cipher-text transmit mode
Open = Otherwise
Gnd = Transmit mode
Open = Otherwise
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