On Thu, 25 Feb 2016 12:40:43 -0800, "Walter E."
wrote:

Without the range extender, there were several dead spots in the wifi
coverage inside the house. After I installed the range extender, the
connections improved greatly.

However, the system fluctuates in coverage. In the same spot, one moment the
signal is "poor", the next moment it is "good" or "excellent". I measured
signal strength both with my smart phone and with my tablet.
What can possibly account for the fluctuations in signal strength, though I
am not making any changes to the system??

Something unique in the home construction in that "spot"? SWAG