[AV Media Matters] Barrium Ferrite posted for Ian Gilmour

[Jim Lindner <jim@vidipax.com>]

Scott and colleagues.
We did some fairly thorough tests on Ba-ferrite tapes for Digital
Betacam,
SP Betacam and DAT within the last 12 months and we found two main
problems.
Firstly the coercivity and particle orientation are quite different from
the standard metal particle tapes so it's difficult to record a strong
rf
level with a uniform envelope unless the machines are modified - and who
wants to start fiddling with the manufacturer's specs on their
equipment?
Secondly, the binders are still a conventional polyester-polyurethane,
which reacts with moisture by hydrolysis in long term storage, so even
though the magnetic particles are stable, you may still end up with an
unplayable tape.
I would agree with JimW about sticking with some of the respects brands
-
they're not perfect but they're much better made. Even the housings on
the
Ba-ferrite tape samples we assessed were not up to the best standards.
Feel free to post this to the list - I'm not signed on at the moment.

Ian Gilmour
Manager, Engineering & Research Group
ScreenSound Australia
[the National Film and Sound Archive]
GPO box 2002
Canberra City ACT 2601 Australia.
Phone 61 2 62482027  Fax 61 2 62482165