I have been unsuccessfully trying to extend the wifi of my Time 2T Capsule with an Airport Extreme 2nd Gen. It works for a while and then loses configuration. I have done everything possible, disconnected it, reset it but it keeps failing, what to do?

What model and firmware is the 2TB TC?

What firmware is the AE?

Does the AE get good signal from the TC in its current location?

Signal can only be extended that is received intact.

Is it extending on 5ghz? As I remember it a Gen2 AE is only single band, although you can choose either 2.4ghz or 5ghz.

I am fairly sure you are going to tell me your TC is AC model..

I would do a couple of things..

1. Fix the wireless name, make it short, no spaces and pure alphanumeric.

2. Fix the wireless channel for 2.4ghz so it is not going to jump around.

3. Get real results from the AE in its current location for signal strength.. this is really only possible on v5 utility. And that is a double pain with Mavericks because you cannot use it.

Apple have removed all the useful diagnostics from the airport utility. There is next to nothing left. So you need to use the computer and its diagnostics to find signal levels in the location.

http://support.apple.com/kb/HT5606