I just installed a new PC for a client today (here in the US) and noticed that there was a piece of paper with "declaration of conformity with FCC rules for electromagnetic compatibility" included with the mouse and keyboard. They aren't wireless. Either way, even if they were, here is the part that I'm curious about.
It says at the bottom, that in order to "comply" with the aforementioned declaration that the device must, according to part 15 of FCC rules:
1)this device may not cause harmful interference
and here's the freaky one,
2)this device must accept any interference received, including interference that may cause undsired operation.
WTF!
Why would they insist that a device accept harmful/debilitating interference?
This is old law. In the USA Part 15 are laws covering electronic step-children. They are not allowed to bother anybody and if anybody bothers them, too bad. In the past CB radio walkie-talkies under 100 mW were under Part 15 law. Now-a-days just about any device is subject to part 15.
It simply means that while the unit may not operate as expected while in the presence of an interfering field, it will not be damaged by that interference.
** Because every electronic device made does just that - it exists in a radio frequency interference filled environment.
The word "accept" is being used here with the meaning of " live with " or tolerate all the legally permitted forms of radio frequency interference. GSM phones at close range would be a big one.
The makers of the item must design it to be tolerant of such interference and even if the device is made to misbehave this does not lead to disaster - ie it simple freezes unit the GSM phone is moved away.
That disclaimer has been on just about every electronic items for the last couple decades. Never really bothered to figure out the warning #2
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Impmon wrote in news: snipped-for-privacy@4ax.com:
It may be possible that some mad EE comes up with a way to solve the interference problem his device is getting... by actively seeking out the sources of the interference and doing something to them. Ok, Star Trek TNG analogy aside, it's possible an active anti-interferance scheme could mess with another device. It's a play nice type rule, as well as an extension of rule 1.
Just my opinion.
Puckdropper
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Is the second bit really in Part 15? It may simply be there to inform the consumer that they have to live with interference, and they put in the line to counter the first bit. "This is legal according to that first line, so why am I not protected by the same token?"
The intent is clear. People using transmitters are only responsible for interference if they are using out of spec transmitters. Being nearby so it can overload that audio amplifier is not a crime. (But a transmitter that isn't "clean", ie putting out harmonics that land in the tv spectrum, is the problem when the neighbor is getting bad tv reception as a result.) Those without technical knowledge blame the transmitters, whether or not they are the actual problem.
Part 15 even includes some things where the right to use the specific radio frequencies is overriden by licensed users of those frequencies. So those cheap 27MHz walkie talkies can't interfere with licensed users (actually I gather there may no longer be a license requirement for CB), but if a licensed user comes on the frequency, the Part 15 user can't complain. They have to standby because they are a secondary user of those frequencies.
Indeed, the disclaimer may be a general boilerplate that is used for any time a Part 15 disclaimer is needed, so the fact that one device actual receives radio signals (that wireless keyboard using 27MHz) and another is merely interfered with (that wired keyboard sends extra characters everytime Joe next door transmits) isn't differentiated.
Yes, I interpreted the second part to mean that if someone were to intentionally try to mess with my electronic systems, then I would have to allow it. My parnoid thoughts were along the lines of, if the government wanted to hack into a system by some electronic means then I would have to let them do it.I know, eavesdropping would be a passive thing, but perhaps they would use active methods to get into a system.
It means that if you buy some poorly designed piece of electronic crap that is affected by a legal, licensed transmitter, you have no right to complain.
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Actually, I could return the poorly designed piece of crap and exchange it for something else. When a store sees a high number of returns on same brand or model, they can refuse to carry them and the company in the end would either have to work on the quality or suffer.
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When you hear the toilet flush, and hear the words "uh oh", it\'s already
too late. - by anonymous Mother in Austin, TX
Spam block in place, no emil reply is expected at all.
I think you've missed the point. This particular matter will only come up in the presence of a strong radio signal. Like if you live near a broadcast station, or next to an amateur radio station. Elsewhere, the signal levels have dropped off enough that they won't be strong enough at your end to cause any problems.
So the manufacturer can decide to design something so nothing will interfere with it by accident (we're assuming that the unit isn't an actual receiver, where obviously things become different), and charge accordingly. Or, it can design something so a reasonably strong signal won't be a problem, and that will take care of most situations.
The person living next to a transmitter will have problems, but they would be a relative handful compared to the overall number of units sold.
This is not a new issue, just because the manufacturers now put such disclaimers in the manuals.
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