Thanks for the link.

One of the aspects we were investigating was whether there was any relationship of the "natural frequency" of the machined anode block, immediately before final assembly with cathode, glass seals etc, to the eventual working frequency of the assembly.

The equipment sounded like SONAR/ASDIC pinging away all day.

In reply to a post by ppppenguin99:

Strictly speaking, a microwave oven should use 2.450GHz while wifi uses 2.412 GHz to 2.472GHz. But microwave ovens aren't designed for frequency stability so even fairly small leakage could muck up wifi. Even if it's spot on frequency if there's a lot of leakage from the oven I suppose it could saturate a wifi receiver where the front end selectivity won't be sufficient to reject 2.450GHz

Useful information about usage of the 2.4GHz ISM band:
https://en.wikipedia.org/wiki/List_of_2.4_GHz_radio_use

I thought 2.450Ghz was channel 9 on the 2.4Ghz WiFi spectrum?

You're right. 2.45GHz is between channels 8 and 9

Wifi chanel frequencies: https://en.wikipedia.org/wiki/List_of_WLAN_channels

As you have indicated, individual magnetrons can vary and do, given that the cathode voltage is directly mains derived, so their working temperatures etc can vary significantly.

This alters their physical dimensions sufficiently to move their operational frequency to a fair extent, as their frequency of operation is highly dependent upon the "rising sun" anode cavity. I forget the description of the other type of anode, with circular apertures at the ends of the slots.

In other words, very distinctly different from, for example, crystal-controlled oscillators, and even typical LC tuned circuits.

It also meant that tuning the equipment involved highly risky procedures.

I have left ACRYLIC running for a couple of days, in another part of the house where it is likely to pick up more WiFi circuits.

There are now 26 circuits showing up.

My own three remain as was.

The other 23 are-

Ch - Quantity
1 - 6
2 -1
3 -1
4
5 - 2
6 - 8
7 - 1
8
9 - 1
10
11 - 3
12
13


Channels 1, 6 and 11 not unexpectedly have most.

Again not unexpectedly, there are no others in the 5 GHz Band.

One SSID started with AUDI.... on Channel 1, is this likely to be an in-car WiFi?

Don't forget that although the wifi peaks at the chosen channel, it spreads to some extent over the two each side. Also if anyone triggers the 40 setting rather than 20, then two separated channels are used.

Agreed as with any modulated radio transmission, whether AM or FM etc.

I am tipping the ones using non 1, 6 and 11 channels are talktalk routers. They really mess up the entire wireless spectrum by defying all standard conventions. They are also the ones set to use 40Mhz as well.

EDIT: Audi do have in car WiFi yep.

Edited by ukhardy07 (Wed 29-Jun-16 21:13:56)

Sorry if i've missed it somewhere... what exactly is the issue with using channels other than 1, 6 & 11?
From the spectrum usage shown here https://1drv.ms/i/s!AnOT_guNf7hGiKRJtvBt0b-iBiPJ9g , by using channel 13 to me it appears that i'm less likely to pollute others airspace and them mine.

Two are identifies as TALKTALK, Channel 9 with 270 Mbps and Channel 2 at 144.4 Mbps, resoectively.

Both have HUAWEI as "Vendor" and there are another two with that Vendoe; but seem unlikely to be TalkTalk..