Dave, I get a wonderful s6 crackle on 70cm when the box is plugged in, too. I didn't have a cookie tin around so I just wrapped the box in aluminum foil and folded over the edges. Guess what, "Faraday Foil" works.<G> Box gets a bit warm, so I don't run it that way.
The box is the source of the problem, with no questions about it. Since Linksys/Cisco was so clear about no warranty after 1 year, I didn't feel bad about taking a look inside, the two halves pop apart, no screws, after the tamper seal is taken off. (It glues them together.) Linksys didn't reply to the issue that there are longer federal statutory warranties against unseen defects--which I consider this to be.
There's no there there, as the saying goes. Nor, any shielding. Not even aluminized paint inside the case. I've seen that used to stop weak RFI, i.e. spray paint the inside of the case with aluminum or zinc "cold galvanize" paint and sometimes it is enough to work, without blocking any vents, etc.
But Friday I emailed the FCC asking how to pursue the issue of whether a device is defective, or perhaps simply was not built in compliance with what was submitted for ClassB testing. (Anyone here know how to formally question that?) CC'd to Linksys, too.
There were some "incidents" in the computer industry, and since Linksys made their reputation by shipping the cheapest possible boxes...I don't know, but I can suspect this box simply never should have been certified ClassB compliant. Computers generate RFI and need shielding. This one has next to none in sight.
Now there's three of us....that we know of.