HDMI cable EMC failures

It seems that he quality of video cables sold in EU should be much better than it is now. I am not talking about mechanical strength or ability to transfer signal through, but the electromagnetic compatibility. The Swedish Electrical Safety Agency, together with other authorities within the EU, has tested HDMI and antenna cables. EMC interference means that unwanted signals are leaked which can interfere with other devices in the vicinity where the cable is connected.

EMC stands for electromagnetic compatibility, which means that different electrical products must work well together. Our homes are filled with more and more electronics and then it is important that our products work together. Much attention is paid to EMC issues in the electronics industry, for example, because disturbances that exceed the limit values ​​directly cause financial damage to production. In homes, however, no attention is paid to EMC limits and we are apparently accustomed to accepting interference. Within EN 55032 it requires Radiated Emissions measurements to be performed from 30MHz to 6GHz.

There are EMC requirements for electrical products that they must meet. There are EU specifications for antenna and HDMI cables, most of the tested cables do not meet them. The Swedish Electrical Safety Agency is the authority in Sweden that handles the EMC directive. The Swedish Electrical Safety Board’s mission is not only to ensure that the products are safe to use, but also that they meet other quality requirements. One of these is the requirement for electromagnetic compatibility (EMC), which among other things ensures that different electrical products or electrical installations do not interfere with one another. EMC requirements are regulated both in Swedish law and at EU level with the EMC Directive.

HDMI cable is a very common product in our homes between TV and different devices connected to it. Of the 30 HDMI cables that were tested, 27 failed. The four groups tested 30 coaxial antenna cables and 30 HDMI cables, of which only 11 percent of the antenna cables met the manufacturers declared attenuation and and only 10 percent of the HDMI cables met an acceptable EMC quality of at least 50 dB coupling attenuation. The test was performed on retail cables and not cables that were supplied with TVs or monitors.

The failed cables caused too much EMC interference when in use. EMC interference means that unwanted signals are leaked which can interfere with other devices in the vicinity where the cable is connected.

A total of 30 HDMI cables and 30 antenna cables were tested in the study. Of these, only 3 HDMI cables held the line, the remaining 27 cables leaked unwanted signals.
It was not revealed which brands were tested, but according to the study high price does not guarantee quality: In some cases, even the most expensive cables performed worst. It should be noted that all cables tested were of quite short lengths of between 1.5 to 3 meters, so longer cables could perform even worse. HDMI cables are said to potentially cause radio interference, like interfere with 2.4 GHz radios, such as Wi-Fi, Bluetooth, wireless mice and headphones etc.

It seems that people chasing cheap-ass products don’t get what the marketing material says. Since their manufacturers race to the bottom price point, the quality of products suffers. HDMI cables are often very cheap, and very crap. Because there was no significant difference when it comes to how interference prone or not the cables were based on price, it seems that everybody is chasing for cheapest production and some just sell their cheaply/badly cables at higher price. For any product incorporating HDMI 1.0 or above it is most likely that the frequency range in the cable will be at least 30MHz to 2GHz. For some models it could be something to do with the fact that older HDMI cables weren’t designed for current standards. The HDMI connection standard has reached version 2.1. As a result, the data transfer capacity of the bus increased from 18 gigabits in the 2.0 standard to 48 gigabits per second.

Use a good quality HDMI cable to start off with including a cable shield well-bonded to the metal connector shell in multiple places. A good quality HDMI cable also has a tight weave with very small openings. For Radiated Emissions the problem is the common-mode noise i.e. the common mode current flowing on the outside of the shield, thus you may require some filtering. Poor quality (usually the cheap ones) with loose shield weaves or cables with pigtail connections to the connector shell, will allow interior signals or common-mode currents, respectively, on the outside of the shield.

In poorly made HDMI cables the wire ends are often exposed. The main culprits of causing problems are the connectors itself and their design. Wires are soldered on PCB, then glue and then the shell. Good cables encapsulate the PCB and cable with copper foil and the cable shield is worn very high up, leaving no exposed places and then the case (metal same that goes in to the end device). The cable core itself often is made from who ever knows and somewhat shielded. Some problems might be solved making a loop or two through a ferrite ring or using the clamp on ones.

Buying anything has become more and more annoying. You have to do research all the time, because reliable brands, price brackets or shops actually sourcing quality products more or less are dying out.

HDMI

The antenna cables also showed similar results: These were also tested against the quality classes used on the market, with only four of the antenna cables meeting the “Class A” requirements (quality of antenna cables shows that they have deteriorated since last test done in 2012). One of the main issues that was pointed out in the briefing is that if poor quality antenna cables are being used to connect set-top boxes or TVs to cable TV networks can cause system wide problems. A somewhat unexpected side effect from this is that it can also cause problems with radio reception in an unspecified area near the poor quality antenna cable, due to interference coming from the cable.

NOTE: Keep in mind that the antenna cables in the EU are different from the cables that are used for cable modems and most other uses in the US. Instead of using F-type screw-in connectors, European antenna cables use Belling-Lee connectors, which are simple push-in connectors.

The Top Five Reasons Products Fail EMI Testing article at https://passive-components.eu/the-top-five-reasons-products-fail-emi-testing/ list reasons why products fail in EMC testing:

PC Board Design—Poor layout and layer stack-up
Cable Shield Termination and Pigtails—Cable shields are not terminated to enclosure or lack of common mode filtering for unshielded products, plus shield pigtails used
Gaps in the Return Path—High frequency clocks or signals crossing gaps in the return path
Power Distribution Design—Poor power distribution network (PDN) design
Shielding Design—Apertures or slots in the shielded enclosure that are too long

Sources:

9 av 10 HDMI- och antennkablar uppfyller inte kraven
https://www.elsakerhetsverket.se/om-oss/press/nyhetsbrev/2021/september/nyhetsbrev-fran-elsakerhetsverket-september-2021/9-av-10-hdmi-och-antennkablar-uppfyller-inte-kraven/

9 av 10 HDMI- och antennkablar släpper igenom strålning som kan störa radio
https://www.hamnews.se/2021/09/29/9-av-10-hdmi-och-antennkablar-slapper-igenom-stralning-som-kan-stora-radio/

“9 out of 10 HDMI cables do not meet the requirements”
https://newsbeezer.com/swedeneng/9-out-of-10-hdmi-cables-do-not-meet-the-requirements/

Many HDMI and Coaxial Antenna Cables in the Market Don’t Meet EU EMC Regulations
https://www.techpowerup.com/287381/many-hdmi-and-coaxial-antenna-cables-in-the-market-dont-meet-eu-emc-regulations

EU testasi HDMI-kaapelit: lähes kaikki reputtivat testissä
https://etn.fi/index.php/13-news/12638-eu-testasi-hdmi-kaapelit-laehes-kaikki-reputtivat-testissae

The Top Five Reasons Products Fail EMI Testing
https://passive-components.eu/the-top-five-reasons-products-fail-emi-testing/

Nytt nummer av Elsäkerhetsverkets nyhetsbrev
https://www.elsakerhetsverket.se/om-oss/press/nyheter/2021/nytt-nummer-av-elsakerhetsverkets-nyhetsbrev3/

Links on HDMI cable EMC design and testing:

https://interferencetechnology.com/hdmi-cables-emi/

https://www.element.com/nucleus/2020/what-you-need-to-know-about-en-55032-and-55035-cispr-32-and-35

https://incompliancemag.com/article/emc-testing-the-eu-experience/

https://www.emcbayswater.com.au/blog/emc-testing/commercial-emc-testing/emc-compliance-hdmi-radiated-emissions-testing-emi/

https://www.unit3compliance.co.uk/hdmi-more-like-hdm-why-thoughts-on-cable-shield-grounding/

https://community.altair.com/community?id=community_blog&sys_id=9124723cdbb57c90e8863978f4961924

https://www.murata.com/en-global/products/emc/emifil/library/pickup/hdmi2

16 Comments

  1. Tomi Engdahl says:

    Hama Coax antennikaapeli 1,5 m naaras/uros 90 dB *
    https://m.motonet.fi/fi/tuote/475293/Hama-Coax-antennikaapeli-15-m-naarasuros-90-dB-

    122401 Hama-antennijohto 90 dB 1,5 m ST
    - Kaksinkertainen suojaus sähkömagneettisten häiriövaikutusten tehokkaaseen vähentämiseen
    - Suojatut johdot takaavat optimaalisen, häiriöttömän kuvan ja äänen laadun
    - 90 desibelin suojausteho ( punos + suojakalvo) suojaksi sähkömagneettisia häiriövaikutuksia vastaan

    Hama Coax antennikaapeli 3 m naaras/uros 75 dB
    https://www.motonet.fi/fi/tuote/475291/Hama-Coax-antennikaapeli-3-m-naarasuros-75-dB

    Hama 90° Coax antennikaapeli naaras/uros 95 dB
    https://www.motonet.fi/fi/tuote/9501462/Hama-90-Coax-antennikaapeli-naarasuros-95-dB-

    Laadukas Hama antennikaapeli virheettömän antennisignaalin välittämiseen vastaanottimelle. Kolminkertainen suojaus ja 95 dB:n suojausteho vähentävät tehokkaasti häiriövaikutuksia. Kaapelin ferriitit lisäävät suojaa erityisesti korkeataajuuksisia häiriöitä vastaan. Suorakulmaiset liittimet säästävät tilaa.

    Hama Coax antennikaapeli naaras/uros 90 dB
    https://www.motonet.fi/fi/tuote/9501460/Hama-Coax-antennikaapeli-naarasuros-90-dB-

    Hama antennikaapeli virheettömän antennisignaalin välittämiseen vastaanottimelle. Kaapelin kaksoissuojaus ja 90 dB:n suojausteho vähentävät häiriövaikutuksia.

    Hama Coax antennikaapeli naaras/uros 100 dB
    https://www.motonet.fi/fi/tuote/9501461/Hama-Coax-antennikaapeli-naarasuros-100-dB-

    Laadukas Hama antennikaapeli virheettömän antennisignaalin välittämiseen vastaanottimelle. Kolminkertainen suojaus ja 100 dB:n suojausteho vähentävät tehokkaasti häiriövaikutuksia. Kaapelin ferriitit lisäävät suojaa erityisesti korkeataajuuksisia häiriöitä

    https://m.motonet.fi/fi/tuote/9501461/Hama-Coax-antennikaapeli-naarasuros-100-dB-

    Reply
  2. Tomi Engdahl says:

    Antennijohto
    https://www.biltema.fi/toimisto—tekniikka/tv-tarvikkeet/antennit/antennikaapelit/antennijohto-2000033284

    Kaksoissuojattu koaksiaalikaapeli, luokka A, ferriittiytimet. Suojauksen vaimennus > 85 dB. Impedanssi 75 ohm. Yhdistetään TV-, DVB- tai TV/SAT-antenniliitäntään. Muotoonvaletut suojatut IEC-liittimet, uros-naaras. Kaksoissuojaus: Alumiinikalvo ja verkko. Väri: Valkoinen. Sisä-Ø: 0,5 mm Ulko-Ø: 5,0 mm Kudos: 64 x 0,12.

    Antennijohto, RG-6/U
    https://www.biltema.fi/toimisto—tekniikka/tv-tarvikkeet/antennit/antennikaapelit/antennijohto-rg-6u-2000033286

    Kaksoissuojattu F-liittimillä varustettu koaksiaalikaapeli, uros-uros. Yhdistetään digitaalivastaanottimeen ja TV/SAT-antenniliitäntään. Impedanssi 75 Ω. Niklattu. Suojauksen vaimennus > 75 dB. Alumiini- ja verkkosuojaus. Väri: Musta

    Antennijohto, Kulma-suora-liitin
    https://www.biltema.fi/toimisto—tekniikka/tv-tarvikkeet/antennit/antennikaapelit/antennijohto-kulma-suora-liitin-2000036108

    Kaksoiseristetty koaksiaalikaapeli rautaytimet. 75 Ω impedanssi. TV, DVB, TV/SAT-antenniliitäntä. Valetut, eristetyt kulma-suora-IEC-liittimet, uros-naaras. Kaksoiseristys: Alumiinikalvo + verkko. Väri: Valkoinen. Sisä-Ø: 0,5 mm. Ulko-Ø 5,0 mm. Punonta: 64 x 0,10.

    Reply
  3. Tomi Engdahl says:

    Hama antennikaapeli 1,5 m 120 dB
    https://www.motonet.fi/fi/tuote/9500393/Hama-antennikaapeli-15-m-120-dB-

    122425 HAMA-antennikaapeli 1,5 m 120 dB PC.
    • Huolellisesti suojattu tukeva metallipistoke takaa signaalien luotettavan siirron
    • Nelinkertainen suojaus sähkömagneettisten häiriövaikutusten optimaaliseen vähentämiseen
    • Helppo kuljettaa joustavan, ympäristöä säästävän TPE-materiaalin ansiosta
    • Joustavilla materiaaleilla toteutettu optimoitu taitossuoja ehkäisee johtojen katkeamisia
    • Laadukkaat materiaalit ja suojatut johdot takaavat erinomaisen, häiriöttömän kuvan ja äänen laadun

    Reply
  4. Tomi Engdahl says:

    Understanding Shielded Cable
    https://www.mouser.com/pdfdocs/alphawire-Understanding-Shielded-Cable.pdf

    Reply
  5. Tomi Engdahl says:

    Many HDMI and Coaxial Antenna Cables in the Market Don’t Meet EU EMC Regulations
    https://www.techpowerup.com/287381/many-hdmi-and-coaxial-antenna-cables-in-the-market-dont-meet-eu-emc-regulations

    Reply
  6. Tomi Engdahl says:

    measure cable shielding book
    https://www.govinfo.gov/content/pkg/GOVPUB-C13-c89ff483e6cd6381d7cf6f7fbd7a3f66/pdf/GOVPUB-C13-c89ff483e6cd6381d7cf6f7fbd7a3f66.pdf

    Reply
  7. Tomi Engdahl says:

    EMC Tutorial Puts You In The Loop
    https://hackaday.com/2021/10/29/emc-tutorial-puts-you-in-the-loop/

    Reply
  8. Tomi Engdahl says:

    I Spent a THOUSAND Dollars on HDMI Cables.. for Science
    https://www.youtube.com/watch?v=XFbJD6RE4EY

    We told you we’d do it, and here it is! Testing a whackload of HDMI 2.1 and 2.0 cables to find out if you’ve been wasting your money on cables for no good reason.

    Viewer comments:

    I don’t even need new HDMI cables but I feel like buying new HDMI cables…

    I bet so many dodgey companies that make hdmi cables are pissed as hell at you right now. Thanks for the information Linus, another video to add to my education playlist grievous cough

    It would be nice to put the failures into consumer terms. For example, “This cable works with 1080p, but not 4K.” “This cable won’t carry ethernet data, but otherwise works.” “This cable simply doesn’t carry video at all.” In other words, when there is a continuity fault, what applications are impacted?

    My test is see if it’s reliable providing a 120hz 4k hdr signal from my PC, but that’s the application I care about, and most probably don’t need a cable that passes that spec anyways. Almost any cable should be able to do 1080/1440p 60hz or 4k30, which for the average user is probably the highest they’re going to use.

    I seriously love this! This is one of those fields where getting a “quality” cable is never verifiable.

    nstaller tester here, from the hundreds of cables that I’ve bought, tested & used, 2 brands have stood out for me with value for money and performance for price : For passive cables- Cable Matters premium certified 2.0 cables the 3M & under will do most HDMI 2.1 functions and all 2.0b functions.

    Active Cables: Monoprice Cabernet series. Have used these on 15M runs and they always work (chroma is 4:2:0) they meet in wall fire ratings, will do all HDMI 2.0.

    Thanks for the video, HDMI cables was definitely not one I knew much about, and your explanation (plus spending a grand on the massive assortment) gave me (and I assume others) a good background on what to look for!

    Very interesting and informative. I would like to see more cable testing on a more granular basis like which length cable brand is best.

    I was seriously expecting Linus to test that THOUSAND dollar HDMI cable that he bought several years ago. He literally said that he wanted to use an oscilloscope to see the tiny gain in conductivity of something like that. THE CABLE CAME IN A CARRYING CASE WITH AN AUTHENTICITY CERTIFICATE!!!

    Linus: buys a cable tester
    The entire cable industry: I’m in danger! * chuckles *

    Thank you for this really helpful video. Reliable information on cables is hard to find. I was recently worrying about what type and brand to buy for when I buy new devices so this explanation and testing video is extremely helpful.

    Reply
  9. Tomi Engdahl says:

    Comment from https://www.youtube.com/watch?v=XFbJD6RE4EY

    I’d be curious to see how commercial AV cables (Extron, Kramer, Crestron, etc) compare.
    I basically only buy consumer cables as a last resort because of how expensive and variable quality they are.

    Reply
  10. Tomi Engdahl says:

    Tarkkana jouluostoksilla: HDMI-kaapelit reputtivat testissä
    https://etn.fi/index.php/13-news/12910-tarkkana-jouluostoksilla-hdmi-kaapelit-reputtivat-testissae

    HDMI on erinomainen standardi, joka on vallannut video- ja audiosignaalin siirron olohuoneissa ja työpöydillä. EU:n sähköturvallisuusviranomaisten tekevä testi kuitenkin osoittaa, että HDMI-kaapelien laadussa on paljon toivomisen varaa.

    Testistä vastasivat neljän maan sähköturvallisuusviranomaiset: Elsäkerhetsverket Ruotsissa, Bundesnetzagentur Saksassa, BAKOM Sveitsissä ja Agentshap Telecom Hollannissa. Testissä oli mukana kaikkiaan 30 kaapelia eri valmistajilta ja peräti 27 näistä reputti eli ei täyttänyt vaatimuksia.

    Testissä kävi ilmi, että yhdeksän kymmenestä HDMI-kaapelista ei täytä EMC-vaatimuksia. EMC -häiriöt tarkoittavat, että signaaleja vuotaa. Tämä voi häiritä muita lähellä olevia laitteita. Testissä käytiin läpi myös antennikaapelien EMC-ominaisuuksia ja vuoden 2012 testiin perusteella antennikaapelin laatu on heikentynyt.

    Reply
  11. Tomi Engdahl says:

    The Label Says HDMI 2.1 But That Doesn’t Mean You’ll Get It
    https://hackaday.com/2021/12/27/the-label-says-hdmi-2-1-but-that-doesnt-mean-youll-get-it/

    Technology moves quickly these days as consumers continue to demand more data and more pixels. We see regular updates to standards for USB and RAM continually coming down the pipeline as the quest for greater performance goes on.

    HDMI 2.1 is the latest version of the popular audio-visual interface, and promises a raft of new features and greater performance than preceding versions of the standard. As it turns out, though, buying a new monitor or TV with an HDMI 2.1 logo on the box doesn’t mean you’ll get any of those new features, as discovered by TFT Central.

    HDMI 2.1 aimed to deliver multiple upgrades to the standard. The new Fixed Rate Link (FRL) signalling mode is the headline piece, providing up to 48 Gbps bandwidth, a major upgrade over the 18 Gbps possible in HDMI 2.0 using Transition Minimised Differential Signalling, or TMDS. TMDS remains a part of HDMI 2.1 for backwards compatibility, but FRL is key to enabling the higher resolutions, frame rates, and color depths possible with HDMI 2.1.

    Thanks to FRL, the new standard allows for the display of 4K, 8K, and even 10K content at up to 120 Hz refresh rates. Display Stream Compression is used to enable the absolute highest resolutions and frame rates, but HDMI 2.1 supports uncompressed transport of video at up to 120 Hz for 4K or 60 Hz for 8K. The added bandwidth is also useful for running high-resolution video at greater color depths, such as displaying 4K video at 60 Hz with 10 bit per channel color.

    Also new is the Variable Refresh Rate (VRR) technology, which helps reduce tearing when gaming or watching video from other sources where frame rates vary. Auto Low Latency Mode (ALLM) also allows displays to detect if a video input is from something like a game console. In this situation, the display can then automatically switch to a low-latency display mode with minimal image processing to cut down on visual lag.

    When HDMI 2.1 Isn’t HDMI 2.1 – The Confusing World of the Standard, “Fake HDMI 2.1” and Likely Future Abuse
    https://tftcentral.co.uk/articles/when-hdmi-2-1-isnt-hdmi-2-1

    Reply
  12. Tomi Engdahl says:

    HDMI-kaapelit reputtivat testissä
    https://etn.fi/index.php/13-news/13574-hdmi-kaapelit-reputtivat-testissae

    HDMI on erinomainen standardi, joka on vallannut video- ja audiosignaalin siirron olohuoneissa ja työpöydillä. EU:n sähköturvallisuusviranomaisten tekevä testi kuitenkin osoittaa, että HDMI-kaapelien laadussa on paljon toivomisen varaa.

    Testistä vastasivat neljän maan sähköturvallisuusviranomaiset: Elsäkerhetsverket Ruotsissa, Bundesnetzagentur Saksassa, BAKOM Sveitsissä ja Agentshap Telecom Hollannissa. Testissä oli mukana kaikkiaan 30 kaapelia eri valmistajilta ja peräti 27 näistä reputti eli ei täyttänyt vaatimuksia.

    Testissä kävi ilmi, että yhdeksän kymmenestä HDMI-kaapelista ei täytä EMC-vaatimuksia. EMC -häiriöt tarkoittavat, että signaaleja vuotaa. Tämä voi häiritä muita lähellä olevia laitteita. Testissä käytiin läpi myös antennikaapelien EMC-ominaisuuksia ja vuoden 2012 testiin perusteella antennikaapelin laatu on heikentynyt.

    Viranomaisten mukaan kaapelin hinnasta ei voi suoraan päätellä sen laatua. Joissakin tapauksissa kalleimmat kaapelit vuosivat eniten.

    HDMI-liitäntästandardi on ehtinyt versioon 2.1. Sen myötä väylän datansiirtokyky kasvoi 2.0-standardin 18 gigabitistä 48 gigabittiin sekunnissa. Tämän mahdollistaa se, että 2.1-standardissa jokaisen johtimen läpi viedään dataa kaksinkertainen määrä eli 12 gigabittiä. Lisäksi kellosignaaleille varattu neljäs johdin otetaan datan käyttöön. Tällä päästään standardin määrittelemään 48 gigabittiin sekunnissa.

    Käytännössä HDMI-kaapelin yli voidaan siirtää ruudulle 60 kertaa sekunnissa virkistyvää 8K-kuvaa tai 120 kertaa virkistyvää 4K-kuvaa. Markkinoilla 2.1-versio on edelleen marginaalisessa asemassa.

    Reply
  13. Tomi Engdahl says:

    Pulling Data From HDMI RF Leakage
    https://hackaday.com/2023/03/07/pulling-data-from-hdmi-rf-leakage/

    A long-running story in the world of electronic security has been the reconstruction of on-screen data using RF interference from monitors or televisions. From British TV detector vans half a century ago to 1980s scare stories about espionage, it was certainly easy enough to detect an analogue CRT with nothing more than an AM broadcast radio receiver. But can this still be done in the digital age? It’s something [Windytan] has looked into, as she reconstructs images using leakage from HDMI cables.

    It does however leave the tantalizing possibility of using this as a medium to wirelessly export data from a compromised machine, and it’s down this route she goes. She finally arrives on a scheme of encoding data as lines of individual colors that look like interference patterns over a desktop, and from there can send and retrieve files. It works for digital audio streams, and as shown in the video below, even an MJPEG video stream, hidden in the noise from a video signal. That’s impressive work, by any standard!

    Using HDMI radio interference for high-speed data transfer
    https://www.windytan.com/2023/02/using-hdmi-radio-interference-for-high.html

    This project was made possible by at least C++, Perl, SoX, ImageMagick, liquid-dsp, Dear Imgui, GLFW, turbojpeg, and v4l2!

    Reply
  14. Tomi Engdahl says:

    https://hackaday.com/2023/03/07/pulling-data-from-hdmi-rf-leakage/

    Reply
  15. Tomi Engdahl says:

    https://hackaday.com/2023/03/10/hackaday-podcast-209-hdmi-tempest-norm-upscaled-seeing-electrons-and-when-the-radios-go-silent/

    Reply
  16. Tomi Engdahl says:

    Clue: happens when a new episode begins.

    Every time you begin to display a program via HDMI, there is a handshaking process where basically the source asks the monitor “Are you authorized to display this content?” Then they agreed upon the resolution.

    When this process goes haywire, this will be your display. I’ll bet you have a Samsung unit.

    1) Try getting a better or shorter HDMI.
    2) Turn everything off and on to force a new handshake.

    Reply

Leave a Comment

Your email address will not be published. Required fields are marked *

*

*