TM 11-5805-424-15/NAVSHIPS 0967-220-9013/TO 31W2-2G-41
input to amplifier IN-9. The high-level output from
(1) With input fsk signals applied, the output of
amplifier IN-9 activates 2-second delay Q11, Q12.
third input amplifier Q15 is applied through REC
CARRIER ALARM THRESHOLD resistor 1A1R11 to the
(a) If the input receive carrier is restored
level threshold, which provides a polar signal (+ 6 volts)
to amplitude detector Q7, Q8, Q9. The amplitude
within a 2-second interval, the amplitude detector
detector provides a low-level output that is inverted by
provides a low level to amplifier IN-10, turning off
amplifier IN-10, providing a high-level output (+ 6 volts)
ALARM indicator lamp 1A1DS2 as described in (1)
through amplifier IN-9. Amplifier IN-9 provides a low-
above.
level output to activate 2-second delay Q11, Q12
(adjustable by REC CARRIER ALARM TIME control
(b) If the input carrier is lost for more than 2
resistor 1A1R12), producing a low level for OR gate
seconds, 2-second delay Q11, Q12 times out, providing
GOB-1 (input interface and common alarm module) that
a high level (+ 6 volts ) to OR gate GOB-1 in the input
holds ALARM indicator lamp 1A1DS2 in the off
interface and carrier alarm module and causing ALARM
condition (b (1) above).
indicator lamp 1A1DS2 to be lighted (b(2)
(2) When the receive carrier is lost, the amplitude
detector provides a high-level output equivalent to no
output from the detectors to amplifier IN-10. The
resultant, inverted, low-level output provides a low-level
Change 3
5-28
