4 ms·

Unfortunately not only with cheap external USB 3.x drives and not only with old MacBook Airs. Connecting an Anker USB-C dock/hub to my MacBook Pro 2016 and late

Unfortunately not only with cheap external USB 3.x drives and not only with old MacBook Airs. Connecting an Anker USB-C dock/hub to my MacBook Pro 2016 and later 2018 would consistently cause interference with the Microsoft Sculpt Ergonomic and Apple Magic Trackpad (both on 2.4GHz). Then I got an Aukey hub (since my wife was happy with one) and the problems have vanished.

xenadu02 7y ago
This is an issue with poorly made USB 3 cables, connectors, and devices. Intel has a white paper about it: https://www.intel.com/content/www/us/en/products/docs/io/universal-serial-bus/usb3-frequency-interference-paper.html https://www.intel.com/content/www/us/en/products/docs/io/uni... > the noise from USB 3.0 data spectrum can be high (in the 2.4–2.5 GHz range). This noise can radiate from the USB 3.0 connector on a PC platform, the USB 3.0 connector on the peripheral device or the USB 3.0 cable. If the antenna of a wireless device operating in this band is placed close to any of the above USB 3.0 radiation channels, it can pick up the broadband noise. The broadband noise emitted from a USB 3.0 device can affect the SNR and limit the sensitivity of any wireless receiver whose antenna is physically located close to the USB 3.0 device. This may result in a drop in throughput on the wireless link. The money quote: > With the HDD connected, the noise floor in the 2.4 GHz band is raised by nearly 20 dB. This could impact wireless device sensitivity significantly. Besides having properly shielded devices and cables (which manufacturers often don't bother doing), they also recommend that the plug in the laptop be fully shielded or enclosed in a metal chassis (which is fulfilled by having an entirely metal case). I don't know of a cheap RF analyzer but I'd like to get one at some point. I'm curious how many common devices actually adhere to the FCC regulations and/or standards like USB 3, compared to how many are just cheaply made.
- GrayShade 7y ago
  > I don't know of a cheap RF analyzer but I'd like to get one at some point. A SDR might work, and they're quite versatile. Unfortunately, the cheap RTL-SDR ones don't get to 2.4 GHz without a downconverter.
- jsjohnst 7y ago
  > I don't know of a cheap RF analyzer but I'd like to get one at some point. That’s one of the features I love about my Aruba APs/controller. Not only does the APs dedicated as AirMonitors/SpectrumMonitors monitor at both the Wi-Fi level and radio spectrum level and shift frequencies as needed, but I can also get a high quality live visualization of radio spectrum interference. Definitely not cheap though!
- amluto 7y ago
  Depending on your definition of affordable: https://www.aimtti.com/product-category/spectrum-analyzers https://www.aimtti.com/product-category/spectrum-analyzers

xenadu02 7y ago

This is an issue with poorly made USB 3 cables, connectors, and devices. Intel has a white paper about it: https://www.intel.com/content/www/us/en/products/docs/io/universal-serial-bus/usb3-frequency-interference-paper.html https://www.intel.com/content/www/us/en/products/docs/io/uni... > the noise from USB 3.0 data spectrum can be high (in the 2.4–2.5 GHz range). This noise can radiate from the USB 3.0 connector on a PC platform, the USB 3.0 connector on the peripheral device or the USB 3.0 cable. If the antenna of a wireless device operating in this band is placed close to any of the above USB 3.0 radiation channels, it can pick up the broadband noise. The broadband noise emitted from a USB 3.0 device can affect the SNR and limit the sensitivity of any wireless receiver whose antenna is physically located close to the USB 3.0 device. This may result in a drop in throughput on the wireless link. The money quote: > With the HDD connected, the noise floor in the 2.4 GHz band is raised by nearly 20 dB. This could impact wireless device sensitivity significantly. Besides having properly shielded devices and cables (which manufacturers often don't bother doing), they also recommend that the plug in the laptop be fully shielded or enclosed in a metal chassis (which is fulfilled by having an entirely metal case). I don't know of a cheap RF analyzer but I'd like to get one at some point. I'm curious how many common devices actually adhere to the FCC regulations and/or standards like USB 3, compared to how many are just cheaply made.

GrayShade 7y ago
> I don't know of a cheap RF analyzer but I'd like to get one at some point. A SDR might work, and they're quite versatile. Unfortunately, the cheap RTL-SDR ones don't get to 2.4 GHz without a downconverter.
jsjohnst 7y ago
> I don't know of a cheap RF analyzer but I'd like to get one at some point. That’s one of the features I love about my Aruba APs/controller. Not only does the APs dedicated as AirMonitors/SpectrumMonitors monitor at both the Wi-Fi level and radio spectrum level and shift frequencies as needed, but I can also get a high quality live visualization of radio spectrum interference. Definitely not cheap though!
amluto 7y ago
Depending on your definition of affordable: https://www.aimtti.com/product-category/spectrum-analyzers https://www.aimtti.com/product-category/spectrum-analyzers