It wouldn't account for all of it , but bias requirements might be
different from your norm.
>Because the tape is wound oxide out and you're trying to record
>through the backing? Just a guess...
>Because it's very thinly coated instrumentation or logging tape?
>Just another guess which I believe less than the first one...
>On 2011-03-03 8:49 PM, Dan Nelson wrote:
>>I found several dozen reels of 1/2 inch black oxide 1.5 mil tape
>>in my storage shed from at least 20/30 years ago.
>>They are 10" pancakes with cardboard seperators with scotch printed
>>on the master carton of 12 but no type number where the paste on
>>sticker was is missing.
>>On my Ampex 440 with "0" in i get like -20/30 out. I tried
>>re-biasing and altering the bias has no effect on the output
>>Any one have a clue why tape would act this way if stored for 20
>>years bulk ???
>Richard L. Hess email: [log in to unmask]
>Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
>Quality tape transfers -- even from hard-to-play tapes.