TM 11-5840-281-35/1
400-pps when RANGE MILES switch S1101 is in 80-mile
negative gate will back-bias diode CR2019 and cause
range) trigger will be routed to flip-flop transistors Q2002
transistor Q2008 to conduct. Transistor Q2008 will
and Q2003, causing Q2003 to conduct and cutting off
produce a positive gate on its collector which will back-
Q2002. A positive gate from -12 volts to 0 volt will be
bias diode CR2024. With diodes CR2019 and CR2024
produced at the collector of transistor Q2003. This
back-biased, diodes CR2020 through CR2023 will
positive gate will cause transistor Q2004 to conduct,
conduct, allowing the radar video to be applied to the
producing a negative gate from +12 to -12 volts on the
base of transistor Q2012. At the emitter of transistor
collector transistor Q2004. Diode CR2014 will become
Q2012, the radar video is mixed with the range marks
forward-biased and transistor Q2005 will conduct. A
and amplified by transistor Q2006. Gate amplifier
positive gate from -12 to +12 volts will be produced at the
transistors Q2009 and Q2010 are identical in operation
collector of transistor Q2005 which will forward-bias
to gate amplifier transistors Q2007 and Q2008, except
diode CR2015. With diodes CR2014 and CR2015
that diodes CR2028 and CR2031 will be forward-biased.
forward-biased, diodes CR2010 through CR2013 will be
With diodes CR2028 and CR2031 forward-biased,
backbiased, preventing iff video from being applied to the
diodes CR2026, CR2027, CR2029, and CR2030 will be
base of transistor Q2006. The continuous trigger thus
back-biased.
applied to transistor Q2003 will cause the flip-flop to
(7) When SCAN MODE switch S1102 is
remain in the iff-off state.
placed to the IFF position, or RANGE MILES switch
(4) When RANGE MILES switch S1101 is
S1101 is placed to the 80-mile range position, -12 volts is
placed to the 80-mile position, the 400-pps trigger is
applied to the base of transistor Q2007, cutting off
applied to the collector of transistor Q2001 as well as the
transistor Q2007. A positive gate is produced on the
base. Each trigger at the base turns on transistor Q2001
collector of transistor Q2007 which will forward-bias
and ensures that transistor is conducting, placing the flip-
diode CR2019 and cut off transistor Q2008. A negative
flop in the iff-on state. The conduction of transistor
gate will be produced on the collector of transistor Q2008
Q2001 prevents the collector circuit trigger from resetting
which will forward-bias diode CR2024. With diodes
the flip-flop. If SCAN MODE switch S1102 is placed to
CR2019 and CR2024 forward-biased, diodes CR2020
NORM, 35 EL, or 60 AZ position, the 400-pps trigger at
through CR2023 will be backbiased, preventing radar
the base of transistor Q2001 will be disconnected, and
video from appearing on the base of transistor Q2006.
the collector input 400-pps trigger will be allowed to reset
Also, -12 volts is applied to the base of transistor Q2009,
the flip-flop to the iff-on state.
cutting off Q2009. A positive gate is produced on the
(5) Radar video is applied to the base of
collector of transistor Q2009 which will back-bias diode
transistor Q2006 through transmission. gate diodes
CR2028 and cut off Q2010. A negative gate will be
CR2020 through CR2023 and transistor Q2012 with
produced on the collector of transistor Q2010, which will
SCAN MODE switch S1102 is placed to any position
back-bias diode CR2031. With diodes CR2028 and
except IFF, and when RANGE MILES switch S1101 is
CR2031 back-biased, diodes CR2026, CR2027,
placed to 5-, 10-, 20-, or 40-mile range. When SCAN
CR2029, and CR2030 will conduct, placing the junction
MODE switch S1102 is placed to the IFF position, or
of diodes CR2022, CR202S, CR2026, and CR2027 at
RANGE MILES switch S1101 is placed to the 80-mile
ground potential; this condition will maintain the correct
range, radar video will be prevented from passing
dc level at the cathode of the crt.
through transmission gate diodes CR2020 through
(8) The negative sweep gate is applied to
CR2023. Gate amplifier transistors Q2007 through
amplifier transistor Q2011, where it is inverted, amplified,
Q2010 operate similar to gate amplifier transistors
and applied to the crt grid. Both the sweep gate and
Q2004 and Q2005, and transmission gate diodes
unblanking signal (ground) must be present before the
CR2019 through CR2024 and CR2026 through CR2031
crt grid will be sufficiently positive to allow the crt to
operate similar to transmission gate transistors CR2010
conduct. The unblanking signal (ground) is applied to
through CR2015.
the cathode of diode CR2032. With the cathode of diode
(6) When SCAN MODE switch S1102 is
CR2032 at ground, the bias level of transistor Q2011 will
placed to any position except IFF, and RANGE MILES
be a point where the negative sweep gate will be able to
switch S1101 is placed to 5-, 10-, 20-, or 40-mile range
cut off transistor Q2011. When Q2011 is
position, transistor Q2007 will conduct, producing a
negative gate from +12 to -12 volts on its collector. This
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