A professional video router can concentrate dozens—or even hundreds—of SDI connections into a relatively small amount of rack space.

That creates a cabling challenge that is very different from running a single SDI cable between a camera and a monitor.

Behind a router, cable diameter, connector size, bend radius, labeling and cable management can become just as important as choosing a cable capable of carrying the required SDI format.

This guide explains how to choose SDI cable for a video router and when Mini RG59, RG59, RG6, BNC, HD-BNC and DIN 1.0/2.3 make sense in professional broadcast rack systems.

START WITH THE ROUTER'S SDI FORMAT

Before selecting the physical cable, determine the highest SDI data rate the router and connected equipment need to support.

Common professional formats include:

• 3G-SDI — commonly used for HD video workflows
• 6G-SDI — used in certain UHD workflows
• 12G-SDI — commonly used to transport UHD/4K video over a single coaxial connection

If the system is being designed for 12G-SDI, the cable assembly should be appropriate for 12G operation at the required distance.

Using a cable simply because it has BNC connectors does not mean it is automatically the right choice for every SDI data rate.

WHY ROUTER CABLING IS DIFFERENT

Consider a router with 64 inputs and 64 outputs.

Potentially, that is 128 individual coaxial connections concentrated around one piece of equipment.

If every connection uses large-diameter coax, the cable bundle behind the rack can become substantial.

High-density router installations therefore require balancing several factors:

• SDI bandwidth
• Transmission distance
• Cable diameter
• Connector density
• Rack depth
• Bend radius
• Cable management
• Serviceability

MINI RG59: AN EXCELLENT CHOICE FOR SHORT ROUTER INTERCONNECTS

Mini RG59 is particularly useful in high-density broadcast racks because it provides a much smaller cable profile than larger coax constructions.

For short equipment-to-equipment connections, that smaller diameter can make a major difference when dozens of cables need to share the same rack space.

Mini RG59 can be useful for connections such as:

• Router to multiviewer
• Router to switcher
• Router to recorder
• Router to converter
• Router to patch panel
• Router to nearby monitoring equipment

AV-Cables offers professional SDI cable assemblies for 3G, 6G and 12G applications using several coax constructions.

WHEN SHOULD YOU MOVE TO RG59 OR RG6?

Mini coax provides important space-saving benefits, but cable size should not be selected based on rack density alone.

Transmission distance matters.

As SDI frequency and cable length increase, attenuation becomes increasingly important.

A short rack interconnect may be an excellent Mini RG59 application, while a substantially longer path leaving the equipment room may justify a larger RG59 or RG6 construction.

In simplified terms:

For a deeper comparison, see our Mini RG59 vs RG59 vs RG6 SDI cable guide.

BNC VS HD-BNC VS DIN ON VIDEO ROUTERS

Large video routers may need so many connections that traditional BNC connectors consume too much rear-panel space.

Manufacturers can address this by using compact interfaces such as HD-BNC or DIN 1.0/2.3.

The three connector formats should not be confused:

• BNC — traditional full-size professional video connector
• HD-BNC — compact high-density professional coaxial connector
• DIN 1.0/2.3 — another compact coaxial interface used on professional equipment

If your router uses HD-BNC, see our HD-BNC cable assemblies.

If the equipment uses DIN, see our DIN 1.0/2.3 broadcast cables.

USE THE CONNECTOR YOUR EQUIPMENT ACTUALLY REQUIRES

One of the easiest mistakes to make when ordering router cables is identifying every compact coax connector as a "small BNC."

HD-BNC and DIN 1.0/2.3 are different physical interfaces.

Before ordering cables, verify the exact connector specified by the router manufacturer.

If two pieces of equipment use different interfaces, a cable can often be built with the appropriate connector at each end.

Examples include:

• BNC to HD-BNC
• BNC to DIN 1.0/2.3
• HD-BNC to DIN 1.0/2.3
• HD-BNC to HD-BNC
• DIN to DIN

A direct cable assembly can eliminate unnecessary adapters from the rack.

WHY CABLE DIAMETER MATTERS BEHIND THE RACK

One large coax cable is rarely difficult to manage.

Multiply that cable by 32, 64 or 128 connections and the situation changes dramatically.

Large cable bundles can:

• Consume valuable rack space
• Make equipment servicing more difficult
• Increase congestion around connectors
• Make individual signal paths harder to trace
• Create unnecessary strain if cables are poorly supported

This is one reason Mini RG59 is so useful for short high-density broadcast interconnects.

The goal is to use the smallest practical cable that still provides the required performance at the required distance.

PLAN THE CABLE ROUTE BEFORE CHOOSING LENGTH

A router may be only three feet away from another piece of equipment, but that does not necessarily mean a three-foot cable is correct.

The cable may need to travel:

• Out of the router
• Into a horizontal or vertical cable manager
• Down the rack
• Across to another rack
• Back through another cable manager
• Into the destination equipment

Measure the actual cable route rather than simply measuring the straight-line distance between connectors.

At the same time, avoid excessive extra cable that must be bundled behind the rack.

LABEL BOTH ENDS

Router systems can contain dozens of visually identical coaxial cables.

Good labeling dramatically simplifies installation and troubleshooting.

A labeling system might identify:

ROUTER OUT 01 → MULTIVIEWER IN 01

ROUTER OUT 02 → MULTIVIEWER IN 02

CAM 01 → ROUTER IN 01

CAM 02 → ROUTER IN 02

Labeling both ends helps technicians identify a signal without tracing an entire cable bundle through the rack.

DON'T HANG THE CABLE BUNDLE FROM THE CONNECTORS

With a high-density router, the combined weight of dozens of cables can become significant.

The equipment connectors should not be expected to support the entire cable bundle.

Use appropriate rack cable management and strain relief so the cable weight is supported before the individual assemblies reach the router.

The final section of each cable should approach the connector naturally rather than being pulled sideways by the bundle.

AVOID UNNECESSARY ADAPTERS

Adapters can solve unexpected field problems, but they should not automatically become the permanent design of a new rack.

If the router has HD-BNC and the destination equipment has standard BNC, consider using a purpose-built BNC-to-HD-BNC assembly.

If the router uses DIN and the destination uses BNC, use a BNC-to-DIN cable.

If one device uses HD-BNC and another uses DIN, an HD-BNC-to-DIN assembly can create the connection directly.

Fewer unnecessary connection points can make the rack cleaner and easier to troubleshoot.

12G-SDI ROUTER CABLING REQUIRES MORE ATTENTION TO DISTANCE

A cable that works reliably for HD-SDI does not automatically provide the same usable transmission distance at 12G-SDI.

Higher data rates place greater demands on the coaxial transmission path.

For short router interconnects, a professional 12G Mini RG59 assembly may provide an excellent combination of compact size and performance.

For longer runs, consider a larger coax construction appropriate for the required distance.

See our 12G-SDI cable distance guide when planning longer UHD signal paths.

A PRACTICAL ROUTER CABLING STRATEGY

VIDEO ROUTER CABLING CHECKLIST

1. Determine the required SDI format: 3G, 6G or 12G.
2. Identify the exact connector on the router.
3. Identify the connector on the destination equipment.
4. Measure the actual routed cable distance.
5. Select Mini RG59, RG59 or RG6 based on distance and application.
6. Allow room for proper cable management.
7. Provide strain relief for large cable bundles.
8. Label both ends of every assembly.
9. Avoid unnecessary adapters.
10. Test each signal path before putting the system into production.

THE BOTTOM LINE

The best SDI cable for a video router is not determined by bandwidth alone.

A professional router installation needs to balance SDI format, transmission distance, coax diameter, connector type and rack density.

Mini RG59 is particularly valuable for short, high-density rack interconnects because it reduces cable bulk. RG59 and RG6 provide additional options as transmission distances increase.

HD-BNC and DIN 1.0/2.3 can help equipment manufacturers fit more SDI connections into limited panel space, but the exact interface must match the equipment.

Designing the cable system around the complete rack—not simply each individual connection—creates a cleaner, more serviceable professional video installation.

PROFESSIONAL ROUTER CABLING FROM AV-CABLES

AV-Cables manufactures professional 75-ohm cable assemblies for broadcast routers, switchers, multiviewers, monitors, converters, patch systems, mobile production and fly-pack applications.

Available configurations include BNC SDI cables, HD-BNC assemblies and DIN 1.0/2.3 broadcast cables for professional 3G, 6G and 12G-SDI systems.

AV-Cables professional cable assemblies are hand assembled in the USA and individually tested before shipment.

AV-Cables — Professional Broadcast Connectivity Solutions