Couple things I forgot to mention in video: 1- The wire on BNC doesn't look like it has any shielding. 2- Looks like whoever assembled these got lazy and just soldered the wires to the pads on board instead of through the holes.
Thanks, as I am in doubt till now whether Video balun is just connectors without any of those stuff inside . Searched video balun manufacturing, video balan breaking etc....finally found this dismantling video balun .
Thanks for this circuit tear down. Can you please provide some calculations of how to build one from scratch? I'm planning to build a custom DVR board and would like to integrate these baluns into the PCB. Why does a balun needs a tiny toroid transformer? I was not expecting to see a torrid lol
Umm, the vast majority of these are short, rigid, and have no components. They sell them anywhere they sell security cameras, like Fry’s Electronics. They have them for power connections (usually 5.5x21.mm), RCA Cinch male/female, BNC, F-type coaxial, and more.
In general, baluns are crap. When you use baluns, the single thing you are relying on the most is the twist in the network cable. The thing that most kills the signal is induction coupled noise. Coax rejects this using its braided and/or foil shielding. Coax also has a relatively thick copper center conductor surrounded with a foam dialectric layer. Not only is the network cable conductor thinner (~26 AWG), but most of the network cable made in the world isn't solid copper anymore. It's copper-clad aluminum. So, it has crappier capacitance AND lower conductivity. So, why use a balun? Well, as this guy says... it's cheap. Under the right circumstances, you'll get a passable-to-decent result. I'd use this if I were setting up cameras for my house, but never if I were selling this to a customer. Even cheap coax is safer to use than this stuff.
The point to the balun and twisted pair wire is to rejetct common mode noise. You don't need to run heavy coax to do that. I develop cameras for dangerous places and my NDA says I can't say exactly where... But we have excellent results running long distances in environments that are very cold to very hot and have a lot of EMF and I'm talking 160,000A worth. We also run Modbus, Profi, DeviceNet and other industrial communications over twisted pair across large plants that aid in critical function... The job is done reliably and done with standard CAT6
