Price : $21.39
Product Description
Features: Easy installation, using the standard UTP cable system Male BNC allows connection directly to the camera or DVR Support all video devices, such as camera, monitor, DVR card and recorder etc. Lower budget, the price of CAT 5 cable is much less than coaxial cable Using UTP cable (CAT 5, RJ45) to transmit video, audio signal instead of coaxial Utilize existing wiring. Already have structured cabling systems? Simply connect a balun at each end of the cable run to transmit your signal. Reduce installation cost. UTP cables physically smaller than coax alternatives, more cameras through a smaller diameter, extremely easy to install and terminate. Better EMI and RFI interference rejection than coaxial cable Lower cable cost. The cost of video balun plus Cat 5 cable may less than traditional wire. Especially for high cost Plenum Coax cables
Buyer Testimonials
These are perfectly competent video baluns, and honestly described in the item description.
On the other hand, all purchasers of such items ought to be aware that whilst such inexpensive passive baluns will present the desired impedance matching and popular-mode rejection, they do NOT provide any sort of isolation at all -- they are wired in an autotransformer configuration.
As a result, they produce ZERO protection for the video ports on your camera/DVR/whatever.
You can see this yourself with out gutting 1 by just employing an ohm-meter to measure the resistance from the balanced line terminals to the BNC terminal -- you will discover that one of the BL terminals is directly connected to one of the BNC terminals, and the other has a incredibly low resistance between it and the other BNC terminal.
Or you can go to the Wikipedia post for BALUN and see a schematic of a typical balun, suitable below the subtitle: "Varieties of balun"
If you are operating video over twisted pair, I sincerely recommend using some sort of grounded lightning/surge protection device between the BALUN and your a great deal more high priced widgets, like a DVR. The newer, cheap security DVRs do not appear to have considerably in the way of internal protection on them, and a nearby lightning strike or whatnot can very easily create voltages on the twisted pair that will fry an input port. Cameras seem to be a lot more durable.
Items function as promised. However they are inexpensive. The spring on the locking ring is weak and the fitting is loose. If you wiggle or bump them the video goes OUT or becomes noisy. This is a discomfort if you put the balun into the camera housing and later have to disassemble the camera once more to wiggle the balun. If I had to do over, I would invest in greater top quality baluns. The size is decent and the reality that there is not a cable hanging of them is also a plus to me. Then again they do perform as lengthy as you dont touch or wiggle them.
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