I have just installed a bit of software which scans and records the local to me WiFi signals....
With my own AP set up to use 11, the scanner shows me on 11 + 7. If I swap the AP channel to 1, it shows as 1 +5. My signal seems to span over both of those channels. Some of the others show as occupying two channels, some as just the one - why two please?
One of the (not mine) AP's most of the time shows as -85dB, but every few minutes it rises to -10db for a few seconds - why? This one shows as two channels, but only seems to be three wide.