Not every SDI connection needs a large cable designed for a long facility run.

Inside a broadcast rack, production fly pack or equipment cabinet, many SDI connections may only travel a few feet between a video router, monitor, converter, multiviewer, switcher or patch panel.

These short equipment connections are commonly handled with SDI patch cables.

But what exactly is an SDI patch cable—and should you choose Mini RG59, RG59 or RG6?

The answer depends on the SDI data rate, required distance, equipment density and physical space available behind the rack.

WHAT IS AN SDI PATCH CABLE?

An SDI patch cable is a relatively short professional 75-ohm coaxial cable assembly used to connect SDI video equipment.

Typical connections include:

• Video router to monitor
• Router to multiviewer
• Switcher to recorder
• Converter to monitor
• Camera control equipment
• Patch panel to equipment
• Rack-to-rack interconnections
• Fly-pack equipment

The term patch cable generally describes how the cable is being used rather than one specific coax construction.

A patch cable could therefore be built from Mini RG59, RG59 or another suitable 75-ohm coax depending on the application.

WHY PATCH CABLE SIZE MATTERS

It might seem logical to use the largest available coax for every SDI connection.

For long runs, lower attenuation can certainly be valuable.

Inside a crowded equipment rack, however, physical size becomes another important consideration.

A large-diameter cable may:

• Require more space behind equipment
• Be harder to route through dense cable management
• Place more mechanical load on connectors
• Require a larger bend radius
• Make high-density installations more difficult to service

For a short connection, a smaller professional coax may provide the required electrical performance while making the installation considerably easier to manage.

MINI RG59 FOR SDI PATCHING

Mini RG59 is particularly useful for short SDI patch cables and high-density rack environments.

Its smaller diameter makes it easier to route behind equipment where dozens—or even hundreds—of coaxial connections may be present.

AV-Cables uses professional Mini RG59 constructions including Belden 4855R for 12G-SDI applications and Belden 1855A for lower-data-rate professional SDI applications.

Mini RG59 can be an excellent choice for:

• Broadcast racks
• Video routers
• Multiviewers
• Production switchers
• Converters
• Monitors
• Fly packs
• Short equipment interconnects

RG59 FOR SDI PATCH CABLES

Standard RG59 provides another useful option when you want additional transmission capability while retaining a more manageable size than larger RG6 constructions.

For 12G-SDI applications, a professional construction such as Belden 4505R can provide a useful balance between cable diameter and transmission performance.

RG59 may be appropriate when the patch run extends beyond the very short equipment connections commonly associated with Mini RG59 or when the installation has enough space for the larger cable.

WHAT ABOUT RG6?

RG6 is often selected when lower attenuation and longer transmission distance become more important.

For example, professional 12G-capable RG6 constructions such as Belden 4694R can be useful for longer SDI paths.

But RG6 may be unnecessary for a two-foot connection between adjacent rack devices.

The larger cable diameter and bend radius can make routing more difficult in dense equipment environments.

This illustrates an important SDI cable-selection principle:

MINI RG59 VS RG59 VS RG6 FOR PATCHING

WHAT LENGTH SHOULD AN SDI PATCH CABLE BE?

The best patch cable is generally long enough to route properly without creating unnecessary excess cable.

A cable that is too short may place tension on the connectors or force the coax into an excessively tight bend.

A cable that is much longer than necessary creates additional cable management and adds transmission loss without providing a useful benefit.

Common short patching applications may use lengths such as:

• 1 ft
• 1.5 ft
• 2 ft
• 3 ft
• 6 ft
• 10 ft
• 15 ft
• 25 ft

The correct length depends on the actual routing path—not simply the straight-line distance between two connectors.

12G-SDI PATCH CABLES

12G-SDI places greater demands on the coaxial transmission path than lower-rate SDI formats.

For short 12G-SDI equipment interconnects, a professional 12G-capable Mini RG59 assembly can provide an excellent combination of bandwidth and manageable cable diameter.

This can be especially useful when connecting:

• 12G-SDI routers
• 4K production switchers
• UHD monitors
• 12G multiviewers
• 12G converters
• UHD recorders

AV-Cables offers 12G-SDI Mini RG59 BNC cables using Belden 4855R for professional short-run applications.

6G-SDI AND 3G-SDI PATCH CABLES

Not every professional video system operates at 12G-SDI.

Many production environments continue to use HD-SDI, 3G-SDI and 6G-SDI equipment.

Professional Mini RG59 cable such as Belden 1855A provides a compact solution for many of these short equipment connections.

As with any SDI installation, cable construction and distance should be matched to the required data rate.

BNC ISN'T THE ONLY PATCH CONNECTOR

Traditional BNC remains extremely common in professional video, but modern high-density equipment may use smaller connector formats.

These include:

• HD-BNC
• DIN 1.0/2.3

Both can allow manufacturers to fit more SDI connections into limited panel space.

Patch assemblies can therefore be configured as:

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

AV-Cables offers professional HD-BNC cables for high-density broadcast equipment and SDI installations.

WHY VIDEO ROUTERS BENEFIT FROM SMALLER PATCH CABLE

A large video router can place many SDI connections in a relatively small area.

Using oversized cable for every short connection can quickly create a bulky cable bundle behind the equipment.

A properly selected Mini RG59 patch cable can reduce bundle size and make individual connections easier to identify, route and service.

The same principle applies to multiviewer systems, monitor walls, mobile production racks and fly packs.

DON'T SACRIFICE 75-OHM PERFORMANCE FOR FLEXIBILITY

Patch cables often need to be compact and flexible, but they still form part of the professional SDI transmission path.

Use cable and connectors designed for professional 75-ohm video applications.

The goal is not simply to find a thin cable. It is to find an appropriately sized coaxial construction capable of supporting the required signal.

SDI PATCH CABLE SELECTION CHECKLIST

THE BOTTOM LINE

An SDI patch cable is more than simply a short BNC cable.

It is part of the same controlled 75-ohm signal path used throughout a professional video system.

For short, high-density rack connections, Mini RG59 can provide an excellent combination of small diameter and professional SDI performance.

RG59 can provide additional transmission capability while remaining manageable, while RG6 becomes increasingly useful as cable distance grows.

The right choice depends on the signal, distance and physical installation.

PROFESSIONAL SDI PATCH CABLES FROM AV-CABLES

AV-Cables manufactures professional SDI cable assemblies for broadcast racks, production switchers, video routers, monitors, multiviewers, converters, mobile trucks, fly packs and professional AV systems.

Available configurations include Mini RG59, RG59 and RG6 coax with BNC, HD-BNC and DIN 1.0/2.3 connector options.

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

AV-Cables — Professional • Reliable • Connected