1 Purpose and Functions
The ACTii AC2051 video balun is a high-quality passive device designed for transmitting video signals from four industrial CCTV cameras using a single twisted pair (UTP) cable. The device performs the key function of impedance matching between the coaxial cable (75 OHM) and the balanced cable (100 OHM), which allows for stable image transmission at a distance of up to 600 meters when using Cat 5 twisted pair cable.
Thanks to the use of a standard RJ45 connector, the balun allows for significant simplification of monitoring installations, reducing the number of required cables and lowering wiring costs. As a passive device, it does not require additional power, which increases system reliability and facilitates installation in places with limited access to the electrical grid.
Main features:
- ✔ Video signal transmission range up to 600m
- ✔ Solid construction made of durable plastic
- ✔ Integrated BNC cables facilitating direct connection to a DVR or cameras
- ✔ Support for 4 video channels via a single RJ45 network cable
- ✔ Effective interference elimination thanks to a high CMRR coefficient (50 dB)
- ✔ Additional mounting brackets allowing the device to be attached to a wall or other surface
Important system information:
Two such devices are required to build a full signal transmission path (one on the camera side, the other on the DVR side).
2 Technical Specifications
| Transmission range | 600 m |
| I/O voltage range | 75 OHM (CVBS) 1 Vpp |
| Insertion loss | -0.5 dB (for f=5 Mhz) |
| Video bandwidth range | 0-50 Mhz (-3 dB) |
| CMRR (Common-Mode Rejection Ratio) | 50 dB (@ 5MHz) |
| Coaxial I/O impedance | 75 OHM |
| Balanced I/O impedance | 100 OHM |
| Crosstalk | -50 dB |
| Coaxial connector type | 4x BNC plug (on cables) |
| Balanced connector type | RJ-45 (8-pin, 4 pairs) |
| Operating temperature | -20°C ... +55°C |
| Relative humidity | < 95% |
| Housing material | Thick ABS plastic |
| Colour | Grey |
| Product dimensions | 35 x 75 x 25 mm |
| Product weight | 120 g |
| Certificates | CE, RoHS |
3 Installation and Connection
Connection diagram:
The device uses standard pairs of wires in a UTP cable. Each of the four pairs is responsible for one video channel:
- Pair 1 (Pins 1 and 2): Video Channel 1
- Pair 2 (Pins 3 and 6): Video Channel 2
- Pair 3 (Pins 4 and 5): Video Channel 3
- Pair 4 (Pins 7 and 8): Video Channel 4
Installation steps:
- Connect the balun's BNC plugs to the video outputs of the four industrial cameras.
- Crimp the RJ45 plug onto the network cable (T568B or T568A standard - keep the same standard on both ends of the cable).
- Plug the RJ45 connector into the port on the balun.
- At the other end of the UTP cable, connect the second ACTii AC2051 balun.
- Connect the BNC plugs of the second balun to the appropriate inputs on the DVR.
4 Safety Instructions and Maintenance
Safety rules:
- The device is designed for indoor use or in suitable outdoor enclosures that protect against moisture.
- Do not expose the device to direct precipitation or water ingress.
- Before starting installation, ensure that the power to the cameras and DVR is turned off.
- Do not exceed the maximum transmission distances specified in the specifications, as this may result in poor image quality or signal loss.
- The device contains no user-serviceable parts. Do not open the housing.
Maintenance:
The device does not require specialized maintenance. If the BNC connectors or RJ45 port become dusty, clean them with compressed air or a dry cloth. Periodically check the stability of the mechanical connections.
5 Troubleshooting
| Problem | Possible cause | Solution |
|---|---|---|
| No image | Poorly crimped RJ45 plug or damaged UTP cable. | Check the continuity of wire pairs in the network cable using a tester. |
| Very poor image quality | Maximum transmission range (600m) exceeded. | Use an active amplifier or shorten the cable distance. |
| Lines on the image / interference | UTP cable runs too close to high-voltage lines. | Change the cable route or use shielded twisted pair (FTP/STP). |