Nitek VH839M User Manual
Page 2
VH839 / VH1639 / VH839M / VH1639M
8 &16 Port UTP Video Hub
INSTALLATION
The VH839, VH1639, VH839M & VH1639M are Video Balun Hubs with
built-in surge protection. The system operates with other NITEK UTP video
equipment including other UTP Video Hubs, standard Video Balun
Transceivers or active receiver units. It can be mounted in a standard 19”
rack cabinet or used as a desktop unit. These systems convert video into
twisted pair signals or vice versa.
The diagram below shows only a few of the many possible configurations.
If you have any questions about your particular application call the NITEK
®
sales or technical offices.
To hook up the any of the units, connect a video coax to the BNC
connector and connect the twisted pair to the matching + and - terminals. For
"M" models, connect the twisted pair using RJ45 connectors. At the other end
of the twisted pair connect another NITEK
®
UTP Video unit in the same way.
The twisted pair is polarity sensitive so if you are not getting proper video try
reversing the twisted pair. It will not hurt the equipment if the pair is reversed
but the video will be unusable.
TROUBLESHOOTING
Many times it is not possible to know where the telephone cables are routed,
so the actual distance of the cable may not be known. An easy way to
determine the actual length of the cable is with an ohm meter. Short the wire
together at one end and measure the resistance at the other end. 24 AWG wire
has a loop resistance of 51 ohms per 1,000 feet, 26 AWG is 82 ohms and 22
AWG is 32 ohms. If you are exceeding the recommended distance for your unit
contact NITEK
®
or your local representative. NITEK
®
manufactures a wide
selection of systems for longer runs and we would be happy to provide you with
the correct solution.
Problem
Video will not sync, wide white jagged area.
Fix/Cause
Reverse wires on twisted pair connection.
Problem
No video at receiver.
Fix/Cause
Check camera video and coax connections.
Check the twisted pair for opens and shorts.
Problem
Ghosts image to the right, horizontal smearing.
Fix/Cause
Check for bridge taps or “T” taps on the twisted pair and
remove them.
"M" Series