At times O can sit anywhere in the house and receive a strong wireless signal on my iPad and or cell phone... At other times I can't get coverage sitting more than 5 feet away. Why

It could be due to interference. Do you have any light dimmer switches, motors, microwaves, fridges, etc in the house. Make a note of what is on when the signal is bad.
Or could be a bad WiFi router (old Netgear perhaps?)...