Dear List,

looking forward to the beginning of a new digitization week: everything is going well in Cambridge thanks in great extent to the support of the members of the list. Huge thanks!

Now, I have a small group of 1/4 inch tapes in the collection on which I am working (ca 1950s-70s, recorded mainly on Ferrographs) which seems to have a track format, which I haven't met before. On those tapes standard half-track and half-track butterfly Studer blocks consistently produce a dual mono signal with unacceptable crosstalk on both channels (bleeding of about -20 dB referring to the signal on the other channel). 

On the other hand, the output of a quarter-track headblock is as follows:

track 1: Signal A
track 3: Signal A + B
track 2: Signal A + B backwards
track 4: Signal B backwards

It would seem that this very small group of tapes would have been recorded on a machine with a very narrow guard-band in comparison to the rest of the tapes I have. What is your opinion about transferring those tapes on a quarter track headblock and keeping tracks 1 and 4?

I would also be curious about which machine could have had a track format that would agree with the former observations.

Thanks for your comments!

Gregorio Garcia Karman
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