Time machine backups on external HDD over WiFi I like to do backups via Time Machine since my TimeCapsule vaporized after 3 years of service. It's only the power supply which is broken but Apple can't fix it they tell me in an Apple Store. A little ridicolous, but anyway...  

I like to use a normal USB HDD to do my backups now and I like to plug that into my router so I can do it via WiFi. Problem: My router (and a short research of mine says it is not only my router) is not able to deal with Mac OS Extended format. He only recognizes FAT and NTSF. Time Machine however always asks to reformat the HDD to Mac OS Extended. I read an article about how to deal with that but it is kinda out of date and didn't work under Mountain Lion. So my question:  

Is there a way of getting Time Machine using a FAT formatted HDD to make backups on?
Time Capsule (networked Time Machine) relies on the share being AFP.  If you can get your router to share the file via AFP everything should work.  My guess is that that will take quite a bit of work though.  You might start with DD-WRT.