signal voltage frequency response shall be measured from camera output to
video monitor input. It shall be plus or minus 2 dB from 60 Hz to 5 MHz
and not more than 3 dB down at 6 MHz. The low frequency distortion shall
be measured for every camera output over every normal program path to the
input of the associated monitor. Distortion shall be less than 2 percent
at line and field rates. Peak-to-peak signal-to-rms noise ratio shall be
measured for every camera output via the normal program path at input of
the associated monitor. Terminate circuits, except the one under test, at
inputs and outputs. Hum and noise shall be 60 dB below 1.0 Vp-p.
2.4.17.3
Video Switchers
Switching shall interface multiple video signals, cameras, with one or more
monitors. Switching shall be timed to occur during the video signal
blanking period, vertical interval switching. When an IDS zone goes into
alarm, a signal shall be sent from the alarm reporting and display
processor to the switcher. When the zone is covered by CCTV cameras,
switcher shall call up the camera views for display on one or more of the
dedicated video monitors wired to the switcher. In the case of multiple
alarms, applicable camera numbers shall be stored in an alarm queue until
zones are manually called up for viewing. First video display out of the
queue shall be from the last reported alarm. Active alarms shall cycle
between the alarm queue and video monitors as various zones are called up
for viewing. Alarms shall not leave the cycle until secured, reset or
placed in access at the alarm reporting and display processor.
Additionally, a sequential monitoring capability shall permit alarm
reporting and display subsystem operation to view zones in numerical order
at an operator adjustable scan rate. Individual cameras shall be capable
of being called up to display zones on the video monitors. Manual controls
for camera switching shall be on front panel of switcher. Switcher shall
be configured [to fit in a standard 480 mm 19 inch rack] [for desk top
console operation]. [Switcher shall be tamper alarmed.] Performance
requirements shall be as follows:
a.
Bandwidth: 30 Hz to 10 MHz with less than plus or minus 0.5 dB
deviation from a flat response;
b.
Tilt:
Less than one percent;
c.
Differential phase: Less than 0.0174 rad one degree at 10 to 90
percent automatic phase level (APL);
d.
Differential gain:
Less than one percent at 10 to 90 percent APL;
e.
Crosstalk:
55 dB at 3.58 MHz;
f.
Gain:
Unity, adjustable plus or minus 3 dB;
g.
Level:
1.0 Vp-p;
h.
Signal-to-noise ratio: 60 dB below 1.0 Vp-p for the frequency
band from 50 Hz to 5 MHz; and
i.
Video connectors:
UHF or BNC.
2.4.17.4
Video Transmission
Transmission shall be by 75-ohm coaxial cable or fiber optics dedicated to
the associated circuit. Interior cable shall be installed in conduit
SECTION 13703N
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