Determining Cable Length
Check the twisted pair for continuity. Do this by shorting the pair of wires at one end and use an ohm meter to check
the resistance at the other end. Use the chart to determine the length of your wires for a measured resistance. Also,
use a multimeter to test the line and make sure there is no voltage on it. Testing each line and recording the length
for each camera run can greatly reduce installation time. For distances greater than 3,000 feet an amplified transmit
source may be needed.
Wire
Gage
500
(150)
1000
(300)
2000
(600)
3000
(900)
4000
(1200)
5000
(1500)
6000
(1800)
22
16 32 64 97 129
161
194
24 26 51 103 154 205 257 308
26 41 82 163 245 326 408 490
Distance in Feet (Meters)
Installation
VH451 w/Passive (Balun) Transmitter
1) Connect Balun to Camera - Using the installation manual provided with the balun connect it to the video
source, usually a video camera. If you have a UTP ready camera connect the twisted pair directly to the
camera video out.
2) Connect Twisted Pair to VH451 - The twisted pair can be connected to either the push-in terminal blocks or
the RJ45 jack.
3) Connect Video Out to your System - Using standard coax cable connect from the video out BNC to your
system as needed for viewing.
4) Set DIP Switches for Distance - Using the chart below set the 8 position DIP switches on the VH451 for the
distance of your tested pair line plus any coax on each end. The modules are numbered to match the
connections. Knowing the distance and setting the switch will save you time and provide you with the best
possible picture. Settings listed are for standard communication cable. Should you be using wire gages less
than 22 awg or shielded wire with less than 10 pair your settings may vary. Call Nitek Tech Support for
help.
5) Connect the Power Supply - Connect a 12/24 VAC/VDC power supply to the power input terminals.
Unmarked Positions are Off
Video
Level Gain
Video
Peaking
Switch Position
1 2 3 4 5 6 7 8
100-400ft
(30-120m)
400-700ft
(120-200m)
ON
700-900ft
(200-275m)
ON ON ON
900-1100ft
(275-330m)
ON
ON ON
1100-1300ft
(330-400m)
ON
ON ON
ON
Distance
>1300ft
(>400m)
ON ON ON ON ON
O
F
F
1
2
3
4
SAMPLE
Switches 1 and 2 are in the ‘OFF’ position
Switches 3 and 4 are in the ‘ON’ position