Balls in tube DRO Resolver to Digital

A while back there was discussions about using ball bearings in a
tube for a DRO scale. The reader used several excited loops to read
its position? I'm not an analog type but would the resolver to
digital converter metioned previously:

http://products.analog.com/products/info.asp?product=AD2S90

allow you to build a ball encoder? Is it easy or a stretch? Any
volunteers to design one? Cost seems reasonable, I'd be happy to
spend $89 for the possibility of an arbitrary length DRO.

AD2S90-EB PRODUCTION Evaluation Boards - COMMERCIAL $89.06
AD2S90AP PRODUCTION PLASTIC LEAD CHIP CARRIER 20 COMMERCIAL $29.16


Roger