1 Purpose and Functions
The ACTii AC2051 video transformer 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 matching the impedance of the coaxial cable (75 OHM) to the impedance of the balanced cable (100 OHM), which allows for stable image transmission over a distance of up to 600 meters when using Category 5 twisted pair cable.
Thanks to the use of a standard RJ45 connector, the transformer allows for significant simplification of the monitoring installation, reducing the number of cables required 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 power grid.
Main features:
- ✔ Video signal transmission range up to 600m
- ✔ Robust construction made of durable plastic
- ✔ Integrated BNC cables facilitating direct connection to the recorder or cameras
- ✔ Support for 4 video channels using a single RJ45 network cable
- ✔ Effective noise elimination thanks to high CMRR (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 complete signal transmission path (one on the camera side, the other on the DVR recorder side).
2 Technical Specification
| Transmission range | 600 m |
| Input/Output voltage range | 75 OHM (CVBS) 1 Vpp |
| Insertion loss | -0.5 dB (for f=5 Mhz) |
| Video bandwidth | 0-50 Mhz (-3 dB) |
| CMRR (Common-mode rejection ratio) | 50 dB (@ 5MHz) |
| Coaxial Input/Output impedance | 75 OHM |
| Balanced Input/Output impedance | 100 OHM |
| Crosstalk between inputs | -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 |
| Color | Gray |
| 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 wire pairs 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 transformer's BNC plugs to the video outputs on the four industrial cameras.
- Crimp the RJ45 plug onto the network cable (standard T568B or T568A - use the same standard on both ends of the cable).
- Plug the RJ45 connector into the transformer socket.
- At the other end of the UTP cable, connect the second ACTii AC2051 transformer.
- Connect the BNC plugs of the second transformer to the appropriate inputs on the DVR recorder.
4 Safety Instructions and Maintenance
Safety rules:
- The device is designed for indoor use or in suitable outdoor enclosures protecting against moisture.
- Do not expose the device to direct precipitation or water ingress.
- Before starting the installation, ensure that the power to the cameras and recorder is turned off.
- Do not exceed the allowable transmission distances specified in the specification, as this may result in poor image quality or signal loss.
- The device does not contain user-serviceable parts. Do not open the housing.
Maintenance:
The device does not require specialized maintenance. If the BNC connectors or the RJ45 socket become dusty, clean them with compressed air or a dry cloth. Regularly check the stability of mechanical connections.
5 Troubleshooting
| Problem | Possible cause | Solution |
|---|---|---|
| No image | Improperly crimped RJ45 plug or damaged UTP cable. | Check the continuity of pairs in the network cable with a tester. |
| Very poor image quality | Maximum range exceeded (600m). | Use an active amplifier or shorten the cable distance. |
| Stripes on the image / interference | The UTP cable runs too close to high-voltage power lines. | Change the cable route or use shielded twisted pair (FTP/STP). |