[TriLUG] can't connect to wap when move it to alternate location

David Black dave at jamsoft.com
Mon Apr 12 21:12:39 EDT 2010


----- "Neil L. Little" <nllittle at embarqmail.com> wrote:

> A microwave ovens operate around 900mhz.

Only very early units none of us likely ever owned. ;-)  Modern microwave ovens operate around 2460 MHz, directly interfering with wi-fi and Bluetooth operation on the 2.4 GHz band.

Even with lots of shielding around the cooking cavity, on a spectrum analyzer it's a big, ugly signal that wanders several MHz in frequency as the oven operates.  It's easy to spot because the energy of a nearby oven is stronger than almost everything else in the band.  However, the duty cycle of the magnetron producing that UHF energy isn't 100%, so there's part of every 60 Hz cycle where it's quiet.  That's when the "microwave oven avoidance" tech in some (most?) wi-fi and Bluetooth gear knows to transmit - of course at a substantial speed penalty.

That's why I prefer channel 1 (2412 MHz) for single-channel wireless installations, as it's furthest away in frequency from most microwave ovens and seems to be least impacted.  (Oh no, now everybody will start using channel 1!)  :-P

Dave



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