--
Belden 4794R A new cable for 12G-SDI signal transmission --
Tue, 29 Nov 2016 11:02
--
Belden recently launched a new cable for 4K/UHDTV (12G-SDI): Belden 4794R.
This coaxial cable is the first of its kind, designed specifically for 4K single-link UHD video in the AV broadcast market for 12G-SDI signal transmission.
Belden s 4794R coax for 4K/UHDTV (12G-SDI) offers superior performance, easier installation and reduced weight and space compared to quad or dual link. They are now working on different sizes of 4K cables, and will be introducing each of them as time goes by.
4K is a term commonly used to describe video display resolution that is about 4000 pixels. That is roughly eight times the resolution of high definition (and four times the resolution of 1080p). The broadcast version of 4K, called UHD (ultra-high definition), has a resolution of 3840 pixels by 2160 lines. DCI (Digital Cinema Initiatives), Hollywood s 4K version, has a resolution of 4096 pixels by 2160 lines. Both have a clock rate of close to 12 GHz, hence the 12G-SDI.
Starting down the path toward 12G-SDI
Several years ago, we created an RG-6 video cable (1694A) that carried HD over 370 feet (113m). But when 3G-SDI hit the scene, that video signal also called 1080p/60 or 1080p/50 was double the bandwidth of high definition (HD), which reduced distance capabilities of 1694A down to 78m.
Although it has changed over the years, the magic distance for video cables today is 100m (328 feet). I ve always wondered where that number came from. Isn t that the distance limitation of data cables like Category 5e, 6 or 6A? How does that apply to video cable?
But then it occurred to me: Most broadcast and video installations use data cables. In fact, some professionals say that these applications will eventually consist solely of data cables. Right now, many installations have a hybrid design with both data and coax cables, so maybe it makes sense that coax cable follow the same rule.
That s when we decided to create the first cable designed specifically to carry signals up to 100m for 3G-SDI, 1794A and we did so about five years ago. This was a slightly larger cable than 1694A. Today, however HD pretty much rules the video world, so the souped-up Type 7 cable we created didn t end up being a hot seller. Even back then, we knew that the next step for video cables would involve 4K.
But would 12G-SDI signal transmission over coax cable ever be possible? Most people said no.
A note about the digital cliff
Now is a good time to point out that the distances quoted in this blog aren t based on field testing. These are calculated values based on a formula that first appeared in SMPTE ST-259M to avoid what s known as the digital cliff.
The farther you go on a cable, the closer you get to the digital cliff. The picture looks fine, so you don t really know how close you re getting. But when you install a cable that s just a little too long, you get no picture. The receiving chip doesn t see enough signal (or noise and reflections mess up the signal), so you get nothing. The difference in length from a perfect picture to no picture could be just a few feet.
If you know the clock frequency, or data rate, of the application, you can determine how far along the cable you can safely go and still maintain a picture. In any digital data system, the actual data cannot go past a frequency of half the clock. This is called the Nyquist limit. Originally, the formula for SD-SDI was -30 dB (attenuation) at the clock frequency. Using this formula, digital signals could easily be sent hundreds, even thousands, of feet before reaching the -30dB distance. Then, with the change to HD, SMPTE standard ST 292 was written with a more conservative formula of -20 dB at the clock frequency. That means that you can t go as far. This safe distance was very conservative.
How Far Does It Go?
As time went by, and HD cable performance continued to improve, we consistently received this type of feedback from customers: I went twice as far as your distance chart indicates! Some customers even said they could go three times as far.
Not only was the cable improving, but so were the connectors and chips sending and receiving the signals. When it looked like 4K would eventually become standard, Belden lobbied to the SMPTE standards group to change the distance formula for these applications. We proposed a new formula and got our wish: -40 dB at the clock frequency. This means that, for a 12 GHz cable, attenuation must be no more than -40 dB at 6 GHz ( the clock frequency of 12 GHz) For the 6 GHz version of 4K, the formula would be -40 dB at 3 GHz.
When comparing the data in the distance chart below, this is why the numbers sometimes don t make sense. The formulas (shown at the top of each column) keep changing. This is just an excerpt of our complete Recommended Transmission Distance Chart. It shows their first 4K cable, 4794R. Download the entire chart here.
There are quite a few new things to notice on this chart. The first is the column for SMPTE ST-425, which covers quad-link 12 GHz for UHDTV1. This was the original 12 GHz delivery system, which split 12 Gbps into four cables. In that case, each cable carries 3 Gbps/3 GHz cable performance, which already exists. But, with the new formula (-40 dB at the clock frequency), they go farther than they did in the previous SMPTE ST-424 standard, even though they are the same cables you ve always been using.
If the cables under the -30 dB and -20 dB formulas can go two or three times the distance shown, where s the cliff for the 12G-SDI cable especially in the SMPTE ST 2082-1 column? The actual location of the cliff is influenced by the quality of the installation, the connectors chosen, the equipment, the chips, the connectors and everything else in the line (patch panels, patch cord
Most recent headlines
06/10/2025
France T l visions, France's leading broadcaster, has received the 2025 EBU ...
04/09/2025
Monumental Sports & Entertainment (MSE), in collaboration with Dalet, has been a...
30/08/2025
WASHINGTON The Federal Communications Commission has adopted its FY 2025 Regulatory Fees Order that establishes the regulatory fee rates for the broadcast stati...
29/08/2025
Australian Red Cross and SBS launch training to help workplaces in the fight aga...
29/08/2025
The National Film and Video Foundation (NFVF), an agency of the Department of Sp...
29/08/2025
L3Harris Technologies has concentrated decades of expertise across the entire enterprise to develop affordable and reliable best-of-breed solutions to rapidly c...
29/08/2025
BURBANK, Calif. The CW Network and the Pac-12 Conference have announced a new media rights deal that will extend their broadcast partnership beginning with the ...
29/08/2025
NEW YORK Gracenote has released a new analysis of its global video dataset showing that the number of FAST channels grew nearly 14% from Q1 2025 and 76% since 2...
29/08/2025
SAN JOSE, Calif. Harmonic has announced a series of improvements to its live sports streaming solution that the company said will improve fan engagement, protec...
29/08/2025
NEW YORK and LOS ANGELES Fox Corp. and YouTube TV last night announced a renewal of the full portfolio of Fox networks, including Fox News Channel, Fox Business...
29/08/2025
Budapest, Hungary, August 2025 - The integration of Microsoft Teams Rooms (MTR) with Lightware's Taurus universal matrix switchers delivers a new level of f...
29/08/2025
Frequency, the engine behind many of the world's best-known streaming television channels, today announced it will launch Studio Live, a next-generation uni...
29/08/2025
In an era when AI and cyber resilience are essential, Scality will mark the 10th anniversary of Scality Day on October 16, 2025 in Paris. This flagship global e...
29/08/2025
Disguise's In-House Creative and Technical Teams Pre-Visualised, Programmed and Delivered Content for the Experience, All Powered by EX 3+
Technology solu...
29/08/2025
Disguise will be demonstrating the latest workflows for TV, film and live events on a number of partner booths at the show
Disguise, the industry-leading tech...
29/08/2025
STOCKHOLM, Sweden Accedo will showcase Accedo Compose, its AI agent-powered modular orchestration layer that assists streaming providers in transitioning client...
29/08/2025
LOS ANGELES Cineverse has announced that it is working with Xperi to bring four of its streaming channels to automobiles for the first time as part of the DTS A...
29/08/2025
DALLAS & ATLANTA Gray Media has announced an agreement with the sports streaming service Victory+ to simulcast 17 Dallas Stars NHL games in 15 television market...
29/08/2025
NEW YORK AND CULVER CITY Comcast NBCUniversal and Amazon have announced new and extended distribution agreements that will expand the content available on their...
29/08/2025
FOOTHILL RANCH, Calif. RED Digital Cinema will feature its Cine-Broadcast Module supporting live broadcast workflows during IBC2025, Sept. 12-15, at the RAI Ams...
29/08/2025
29 Aug 2025
Kyivstar Rings Opening Bell at Nasdaq Marking Landmark Listing and ...
29/08/2025
More than half of all NFL games live on Sky for the first timeFriday 29 August 2025
Sky Sports has announced a new three-year deal with the NFL, extending its ...
29/08/2025
Back to All News
RIV4LRIES: The Trailer of the New Series With Samuele Carrino ...
29/08/2025
Get ready for an inspiring and emotional insight into the world of competitive Irish dancing with My Story: Tomi Champion of the World airing on RT 2 this monda...
29/08/2025
RT has today announced that David McCullagh is to be the new presenter of RT Radio 1's flagship Today programme, which airs every weekday at 10am, replaci...
28/08/2025
By Kristin Feeley, Director, Documentary Film & Artist Programs
If you want to tell untold stories, if you want to give voice to the voiceless, you've got ...
28/08/2025
Directed by Steven Bognar and Julia Reichert, Sundance Institute-supported Amer...
28/08/2025
Corridos have been a cornerstone of M sica Mexicana for generations, telling stories rooted in everyday life. Now, a new chapter is taking shape: motivational c...
28/08/2025
Los corridos han sido un pilar de la M sica Mexicana durante generaciones, contando historias enraizadas en la vida cotidiana. Ahora, un nuevo cap tulo est tom...
28/08/2025
Earlier this month, we promised our Verano Forever party would bring the heat, a...
28/08/2025
L3Harris will provide the Polish F-16V fleet with the Viper Shield electronic warfare system as part of an upgrade program....
28/08/2025
Bilbao, August 26, 2025 - AgileTV, an international television and video technol...
28/08/2025
Ken Wilkinson is an Emmy Awards nominated New York audio engineer who specialises in production sound mixing for film, commercial, episodic and documentary work...
28/08/2025
NEW YORK FuboTV today announced that it will launch Fubo Sports, a skinny bundle that focuses on sports with a subscription price of $56 monthly....
28/08/2025
NEVADA City, Calif. At IBC2025, Sept. 12-15 at the RAI Amsterdam, Telestream will debut its new Global Ingest strategy, introducing a next-generation ingest arc...
28/08/2025
Dr. Rhoda Bernard Releases Groundbreaking Debut Book on Accessible Arts Educatio...
28/08/2025
TAG Video Systems, the leader in software-based IP end-to-end workflow monitoring, deep probing, and real-time visualization, has named Oliver Gappa as Sales Di...
28/08/2025
AI-based voice enhancement will be among a series of innovations making their IBC 2025 debut on the DHD stand B46 in Hall 8 at the RAI Amsterdam Convention Cent...
28/08/2025
Telef nica Servicios Audiovisuales (TSA), the leading system integrator and service provider in the media sector in Spain, with the support of Appear, the globa...
28/08/2025
To fully immerse sailing fans in the world's biggest offshore yacht race, production company, Optical Media turned to LiveU's On-site Production solutio...
28/08/2025
Working with Calrec on its most recent overhaul, radio and television broadcaster, WNED has migrated to a fully IP infrastructure with multiple Type R consoles,...
28/08/2025
Cleeng, the Subscriber Retention Management (SRM ) inventor, has unveiled Cleeng Pro, the first-ever direct-to-consumer (D2C) subscription management platform t...
28/08/2025
Zixi, the industry leader in live broadcast-quality video over IP, today announced that French media distribution platform OKAST has selected Zixi to enable rel...
28/08/2025
Solution offers a streamlined, speaker-free architecture to optimize integration with premium external loudspeakers and advanced loudness metering
Nixer Pro Au...
28/08/2025
Cinegy, the premier provider of software-defined television technology, has announced a strategic partnership with Vision One Touch Film Production Services L.L...
28/08/2025
Telestream, a global leader in media workflow technologies, will debut its new Global Ingest strategy at IBC2025, introducing a next-generation ingest architect...
28/08/2025
Tier 1 operator selects Broadpeak to power high-performance, unified CDN solution across Norway, Sweden and Finland
Broadpeak, a leader in streaming and moneti...
28/08/2025
Leading video software provider, Synamedia, today announced that 24 Frames Digital, one of India's leading live event streaming service providers, has chose...
28/08/2025
Meet VisualOn at IBC2025: See What's Next in AI-Powered Video Streaming Join VisualOn at IBC2025 and discover how our AI-driven Optimizer and advanced media...
-- 
