RE: [AV Media Matters] Print-through

[Jim Wheeler <Jimwheeler@aol.com>]

Graham

Who did you talk to at Quantegy?  The baking tests we ran at Ampex was over a three year period and we baked some of the same tapes several times.  They were always recoverable and there was no indication of any degradation.

My question is why bake a tape several times?  I bake it once and copy it.

Regards print-through.  The temperature in the print-through equation is in
KELVIN--not Fahrenheit, so the few degrees increase normally used for baking
should have little or no effect on print-through.  The best article about
print-through is in the October 1980 issue of the Journal of the AES by Neal
Bertram.  Neal was my Mentor at Ampex at that time.  He is now a Professor
at
The Center for Magnetic Recording Research at UC San Diego.

Regards tape packs.  The layer-to-layer forces are the greatest about 1/3 of
the way out from the hub.  The forces can become so great that they go into
compression.  When that happens, the layers distort.

If the outer radius divided by the inner radius is less than 2.5,  these
forces are greatly reduced.  That's why I prefer reels with large diameter
hubs.

Jim Wheeler