transistor equivalent

hi friends
i have a problem, whenever i try to get a transistor in market i find them very obsolete one . how can i know whether a particular transistor is new one or old one by its part number.
can i get equivalent transistor source??
i need BF494 for my project. i cant find it ,pls somebody tell me some alternative transistor which r available in market(not obsolete).

zaved

Perhaps you might try filling your location in?.

2n3904. Bc547.

It cross-references to an NTE229.