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  • I just watched a really good YouTube video by Tom Carpenter on the CWNP channel.   It's entitled USB 3.0 Interference in 2.4 GHz.

    It's available at:   https://www.youtube.com/watch?v=MA979zIpTWg&feature=push-u&attr_tag=adeGnnlKHswkAY7P-6

    Not only does Tom talk about the phenomenon, he shows some spectrum analyzer displays that clearly show the noise level they produce.   He also gives some quantitative numbers as to the amount of interference.

    Personally I didn't appreciate how wide-band the noise really is - much more than the microwave ovens I sometimes come across.

    I was originally just going to add a link into an existing Forum post, but I could not find one on USB 3.0, so I created this one.    I recommend this video to everyone.

    In addition to this video, here is a link to an Intel paper on the same subject:

    https://www.intel.com/content/www/us/en/io/universal-serial-bus/usb3-frequency-interference-paper.html

    Besides Wi-Fi, this document talks about the USB interference impacting wireless mice, keyboards, and Bluetooth devices.   It also includes several mitigation ideas.

    Personally, I am interested in this as some USB 3.0  devices can simultaneously run Wi-Fi & Bluetooth radios and I am concerned about their interaction.

    Big thanks Tom !

  • I just saw an interesting YouTube video by fellow Ham operator,  Bryan - AI6US on the RF noise caused by plug-in USB fast chargers.

    He did not have a spectrum plot of the interference, but he demonstrated the noise on the AM band, and his UHF radio.

    It's so bad on AM it will completely knock out the radio in his truck, if it is merely plugged in.

    I did not see an FCC sticker on his example, but it did have a CE mark.

    Buyer beware.

  • By Petri - edited: November 20

    I hadn't noticed your original post on USB3. I know cases where Mac users have random Wi-Fi outages. There is no apparent pattern - until you check the times. The outage occurs every 60 minutes. That's how often TimeMachine kicks in and take a differential backup to the external USB3 disk with a cheap cable. If the Wi-Fi is on 2.4GHz you can't receive until the backup is over. The length of the outage depends on the amount of data copied, which varies. Sometimes you don't even notice, other times you will.

  • Interesting.  Good catch.

    My first guess would have been to suspect 1) a hardware buss routing or contention  problem,  or 2) a scheduling error involving a bad thread/task priority level. 

    Not that you would expect either from Apple - although we do know that Apple likes to "interpret" MAC rules differently.

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