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RF Shielding History: When the FCC Cracked Down on Computers

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Re: RF Shielding History: When the FCC Cracked Down on Computers

#31

Post by sokoloff »

dontlaugh wrote: post #30
superkuh wrote: post #2

I wish the FCC would go back to doing their job re: radio interference and unintentional emissions. The entire concept of a computer case 'window' is about equally as anti-social and rude as littering in a public park. But it's so pervasive and socially accepted when I bring it up the only responses I receive are all quite hostile. Even worse are the computer builds that don't have any metal case at all. They're broa…

I also don’t get the point. Why would you want to look inside your PC or even have lots of coloured lights in it to look at?

I think the insides of a PC look more interesting than a flat piece of sheet metal. Adding addressable LEDs make that even more true.

Visually, I don't care particularly much one way or the other, but on a 6-12 layer PCB, there's plenty of opportunity to closely couple and shield fast-changing signals, so I wouldn't expect surrounding in a Faraday cage would be needed (and certainly I've never noticed an issue from the computers near my RF receivers).

Re: RF Shielding History: When the FCC Cracked Down on Computers

#32

Post by dontlaugh »

sokoloff wrote: post #31
dontlaugh wrote: post #30

Earlier quoted context omitted.

I also don’t get the point. Why would you want to look inside your PC or even have lots of coloured lights in it to look at?

I think the insides of a PC look more interesting than a flat piece of sheet metal. Adding addressable LEDs make that even more true. Visually, I don't care particularly much one way or the other, but on a 6-12 layer PCB, there's plenty of opportunity to closely couple and shield fast-changing signals, so I wouldn't expect surrounding in a Faraday cage would be needed (and certainly I've never noticed an issue from t…

Neither is very visible under your desk, except for possibly the front of the case.

I went out of my way to avoid extra lights, which sadly wasn’t possible for the GPU. I had to figure out how to turn those off in software.

Re: RF Shielding History: When the FCC Cracked Down on Computers

#33

Post by Flamingoat »

elevation wrote: post #25
Flamingoat wrote: post #20

Earlier quoted context omitted.

If I turn my kettle or microwave on in my kitchen it will kill any bleutooth or wifi signal. My microwave is getting on for 15 years old, maybe newer ones are better, but the kettle was bought last year.

If you cannot change the microwave, consider trying a different wifi channel. I once had a 2012 Panasonic microwave that killed 802.11g channels 7 and 14 but not channel 0.

I am not too bothered about it. I only use it every other day for about 3 minutes to heat up some porridge. I keep on meaning to buy a new Microwave, I bought it in ASDA 15 years ago for £30 and it just keeps on working.

Re: RF Shielding History: When the FCC Cracked Down on Computers

#34

Post by bji9jhff »

mrandish wrote: post #29

Having lived through the early 8-bit home computer era as a teenaged user and then in the mid-80s working in tech startups making hardware peripherals for 16-bit computers - although not as a hardware designer, here's my perspective. Early digital devices definitely could occasionally cause interference with TVs and radios in their immediate area, so there needed to be some regulation to address the issue. However, o…

I like how you described how I imagine OSA will be used.

Re: RF Shielding History: When the FCC Cracked Down on Computers

#35

Post by tzs »

alwa wrote: post #24

I was gratified by the last little tidbit: a nod to the Ohio “tinkerer” whose 2019 experiment in home automation interfered with neighbors’ 315MHz-band devices to the point that the power company shut off the whole block in an attempt to isolate the interference https://www.nytimes.com/2019/05/04/us/key-fobs-north-olmsted... ( https://archive.is/aTWZ2 ) Apparently the regulations work well enough to provoke an offici…

I know someone who lives in Bremerton, WA. Every so often lots of garage door openers and car keyless entry systems and key fobs intermittently stop working for a few hours and this can go on for weeks.

It correlates with aircraft carriers coming to the Bremerton naval shipyard for repair work.

The 315 MHz band for unlicensed low power civilian devices overlaps with several military bands, and the military users have priority (i.e., if they interfere with civilians it is the civilians' problem, and if civilians interfere with the military it is the civilians's problem).

In particular a band used for air-to-ground aircraft communications includes the 315 MHz band. Apparently when a carrier is at the shipyard for repairs they take advantage of that opportunity to test and tune up the radio systems.

They also have radar that uses frequencies in the 315 MHz band. There was an incident in the news in 1999 when the USS Carl Vinson visited Hobart, Australia and disabled nearly every garage door opener within about 10 km of the port while is was pulling in and docking. It was fine once docked because they don't need the radar when not underway.

Re: RF Shielding History: When the FCC Cracked Down on Computers

#36

Post by superkuh »

dontlaugh wrote: post #30
superkuh wrote: post #2

I wish the FCC would go back to doing their job re: radio interference and unintentional emissions. The entire concept of a computer case 'window' is about equally as anti-social and rude as littering in a public park. But it's so pervasive and socially accepted when I bring it up the only responses I receive are all quite hostile. Even worse are the computer builds that don't have any metal case at all. They're broa…

I also don’t get the point. Why would you want to look inside your PC or even have lots of coloured lights in it to look at?

It is a form of costly signalling.
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