Originally Posted by
grumpy
You need to check both signal strength and signal to noise ratio (SNR). Signal strength can fall due to geometry (i.e. as you move around the house, affected by shape and relative orientation of antennas not just size) and SNR can fall due to interfering sources (say, a neighbour's Wifi or some other RF source turning on and off - which would explain the intermittent behaviour).
A signal strength meter doesn't necessarily report just YOUR signal level. It can also report the total level due to your signal and interfering sources in the relevant bands. Interfering sources, by definition, reduce your SNR. In other words, you can appear to have a good signal level but lose out due to SNR levels.
Check what WiFi channels are being used. A lot of Wifi routers default to using the same channel (even from different vendors) and need to be specifically configured to use different channels to avoid interference. Some routers do have a mode of picking an optimal (least interference) channel, but not all do that particularly well. Most (non-router) devices scan, but it doesn't hurt to look up what settings they use for searching (some are configured to a particular channel).
It's possible the wife's laptop (on your desk) is sitting in a sweet spot. Or that its wireless is leaking between channels, and causing interference for other devices.
The other thing to check is the power setting for all of your devices. If one is not putting out enough power it (or devices communicating with it) may have trouble. Power saving features typically affect that, if enabled.