Product Description

12G UHD-SDI BNC Male to Female Extension Cable – Belden 4855R Mini RG59

Extend an existing SDI cable run while maintaining professional 12G-SDI performance with this lightweight BNC male-to-female extension cable.

Built with genuine Belden 4855R Mini RG59 coaxial cable, this assembly is designed for professional 12G-SDI, 6G-SDI, 3G-SDI, HD-SDI and SD-SDI video applications. The compact Mini RG59 construction provides high-bandwidth 12G performance in a thinner, lighter cable that is easier to route around cameras, monitors, equipment racks and production systems.

The integrated female BNC connector attaches directly to the male BNC connector of your existing SDI cable, while the male BNC connector connects to your camera, monitor, switcher, router, converter or other SDI equipment.

This eliminates the need for a separate BNC barrel coupler and provides a clean, professional way to add length to an existing SDI cable.

Each cable is hand assembled in the USA, built with professional precision 75-ohm BNC connectors and individually tested before shipment.

Key Features

• BNC Male to BNC Female configuration for extending existing SDI cables
• Supports 12G-SDI, 6G-SDI, 3G-SDI, HD-SDI and SD-SDI
• Designed for professional 4K UHD video transport
• Genuine Belden 4855R Mini RG59 coaxial cable
• Thin, lightweight Mini RG59 construction
• Approximately 4.5 mm cable diameter
• Silver-plated copper center conductor
• Precision 75-ohm BNC male and female connectors
• High-performance foil and tinned copper braid shielding
• Flexible design for cameras, racks and production equipment
• Multiple lengths and colors available
• Hand assembled in the USA
• Individually tested before shipment
• Lifetime BNC connector replacement warranty

Lightweight 12G Mini RG59 Design

Belden 4855R combines professional 12G-SDI performance with the reduced diameter and weight of Mini RG59 coax.

At approximately 4.5 mm in diameter, 4855R is considerably smaller than conventional RG59 and RG6 video cable. This makes it especially useful where cable size, weight and routing flexibility are important.

The smaller profile helps reduce cable bulk behind equipment and makes installation easier in high-density environments.

Ideal applications include:

• Broadcast cameras
• Cinema cameras
• Camera rigs
• Production switchers
• SDI monitors
• Equipment racks
• Video routers
• Patch panels
• Fly packs
• Mobile production systems
• Control rooms
• Short equipment extensions
• High-density installations

Extend Your 12G SDI Cable Without a Separate Coupler

The integrated female BNC connector connects directly to the male BNC connector of your existing SDI cable.

Instead of:

BNC Cable → Barrel Coupler → BNC Cable

you get:

Existing BNC Cable → AV-Cables 12G Extension Cable → Equipment

This eliminates a separate barrel adapter and provides a cleaner extension connection with fewer individual components in the signal path.

Professional 12G-SDI / 4K UHD Performance

Belden 4855R is a professional 75-ohm Mini RG59 coaxial cable engineered for high-bandwidth digital video applications, including single-link 12G-SDI.

Compatible video formats include:

12G-SDI • 6G-SDI • 3G-SDI • HD-SDI • SD-SDI

This makes one extension cable suitable for modern 4K UHD production systems while maintaining backward compatibility with existing SDI equipment.

Belden 4855R supports approximately:

• 12G-SDI — up to 150 ft
• 6G-SDI — up to 215 ft
• 3G-SDI — up to 310 ft

Important: When used as an extension cable, the extension becomes part of the complete signal path. Maximum transmission distance is based on the combined length of the original cable and extension cable, along with the SDI format, connectors and equipment being used.

For example, adding a 25 ft extension to an existing 100 ft cable creates an approximately 125 ft total signal path.

Designed for Professional 4K Video Systems

The high-bandwidth construction of Belden 4855R makes this cable ideal for connecting and extending professional video equipment including:

Broadcast Cameras • Cinema Cameras • Production Switchers • SDI Monitors • Video Routers • Recorders • Converters • Multiviewers • Patch Panels • Equipment Racks • Fly Packs • Mobile Trucks • Studios • Control Rooms • Corporate AV • Houses of Worship • Live Production

Product Specifications

Why Choose 4855R Mini RG59?

12G-SDI Performance — Designed for professional single-link 12G-SDI and 4K UHD video applications.

Smaller Cable Diameter — Mini RG59 construction reduces cable bulk compared with conventional RG59 and RG6.

Lower Weight — Excellent for camera rigs, portable production equipment and installations where cable weight matters.

Easy Routing — The approximately 4.5 mm cable diameter makes routing around equipment and through crowded racks easier.

Backward Compatible — One cable supports 12G-SDI as well as 6G, 3G, HD and SD-SDI equipment.

No Separate Barrel Coupler — The integrated female BNC connector provides a simple way to extend an existing male BNC SDI cable.

4855R vs. 1855A Extension Cables

Choose Belden 4855R when you need the lightweight Mini RG59 form factor with support for 12G-SDI and 4K UHD.

Choose Belden 1855A when your application requires up to 6G-SDI and you want an even smaller Mini RG59 cable.

For applications where maximum transmission distance is more important than cable size and weight, consider one of our larger-diameter professional RG59 or RG6 SDI extension cables.

Built & Tested by AV-Cables

AV-Cables has manufactured professional cable assemblies for broadcast, video production and commercial AV applications since 1994.

Every 4855R extension cable is hand assembled by our technicians in the USA and individually tested before shipment for dependable professional connectivity.

Lifetime BNC Connector Replacement Warranty

AV-Cables backs this assembly with our Lifetime BNC Connector Replacement Warranty, providing additional confidence for professional broadcast, production and AV installations.