Most of you are aware of the squealing problem which has developed in Ampex 456 tape over the years.
These were excellent quality tapes with a very "hot" high end, which made it ideal for the hobbyist on a budget. For the first time, a radio program could be recorded at 3 3/4 ips with virtually no loss in high frequency response. Being such an excellent tape, it was sold to most of the other tape manufacturers (under different names of course).
Ampex qualified the primary 456 tape and those runs that didn't meet spec were sliced and sold as progressively decreasing quality tapes. The inner cuts ended up as 406. The outer cuts as 291, Strand, and a variety of Scotch numbers. They are readily identifiable by their characteristic brown color tape with black back-coating. They are all 1.5 mil tapes.
I Have developed an electro-chemical process over the last four years that appears to completely "fix" the problem. Unlike other processes, the high-frequency response is restored. Tapes I have repaired two years ago are still in fine shape today.
I charge $6.00 per tape for the repair plus $4.50 shipping/handling. The shipping charge is the same for each 10 tapes repaired (i.e. if you send 10 tapes the total charge would be $64.50.
If you wish me to transfer the tapes for you, add $2.00 per tape for transfer onto a Reel/Reel tape of the same length supplied by you. I can supply the tapes if you wish. contact me for those prices, and for transfer to cassette, DAT, or video tape.