We've got some AGFA PE46 tapes that are shedding a brownish/yellow
'powder' when played back. The layers of the tape aren't adhering to
each other or squealing, but the shedding particles are magnetic so
presumably it's the actual oxide. There are no obvious physical defects
that I can see other than the oxide layer having 'streaky' parallel
lines running the length of the tape. It seems to be affecting about
one in fifteen, with the others playing back okay.
The batches of tapes are from the same recordist and have presumably
been stored in a similar condition, he's also made a note on several
tapes stating 'cleaned of powder' or 'powdery' about a year after they
were recorded (1970's).
Any ideas what the problem might be?
Thanks in advance.