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Re: 2.4GHz QRM [was: ...Central States VHF Society Meeting]



WiFi on channels 7 and above in the US is outside the 2.4 GHz ham  
allocation, if I recall correctly.  I can't recall how much channel 7  
spills into the ham bands but it isn't much.

Convincing the manufacturers to have their base stations either  
default to a high numbered channel (say, 11) or concentrate their  
"automatic" channel selection in 7-11 would help a lot, since most  
people just take the base station/WAP out of the box, plug it into  
their router, and go.  (How many wireless networks around you still  
have the SSID "linksys"?)  It won't eliminate the QRM, but it will  
help.  Especially if downloadable software updates can include this  
behavior.  Some manufacturers are more cooperative than others ..  
Apple used to use channel 1 as the default for their base stations,  
and recently switched to 11 for current base station firmware.  Not  
sure if Linksys does the same or not.

Convincing individual users to stay out of channels 1-6 is likely to  
be a lost cause, since there's not really any way to compel them to  
do so.  (Note, most of these people are the ones who a generation or  
two ago would immediately begin harrassing the nearest ham if their  
TV reception wasn't perfect, whether or not said ham was transmitting  
on 6 meters or anywhere else.)

I suppose if the FCC decided to change the regulations governing WiFi  
devices, they could mandate channel allocations outside the 2.4 GHz  
ham spectrum, but given their enthusiasm for BPL, I wouldn't hold my  
breath.  That's the nature of Part 15, folks ..

On Jul 30, 2006, at 9:52 AM, John Mock wrote:

> I ran into this problem with a 2.4GHz cordless phone at another ham's
> place in the countryside.  I could not hear AO-40 at all with a BBQ
> dish.  We caused it to select another channel, i think by pushing the
> relevant button, and the QRM went away.  I bet the same thing applies
> to wifi.  If/when we can get people at least to avoid using Channel 1
> (and perhaps those near it), that could at least mitigate the problem.
> Alas, that may not be very helpful in high density urbanized areas and
> requires cooperative neighbors (or, in the 'States, someone who can
> convince them that they are required to comply with Part 15).
>
> 		    -- KD6PAG  (Networking Old-Timer, Satellite QRPer)
>
> P.S. Hmmm, i wonder what Hollingsworth has to say about all of this...

Heard from a flight instructor:
"The only dumb question is the one you DID NOT ask, resulting in my  
going out and having to identify your bits and pieces in the midst of  
torn and twisted metal."
----
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