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

6 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

Leave a Comment

Your email address will not be published.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

*

*