02-17-2017, 11:56 AM
It was a very clever system. The tape was pulled by vacuum into two glass fronted slots one either side of the capstan wheel. There were photo sensors at each end of the columns that were part of the spool reel servo system. Each spool reel motor had a servo amp that maintained the loop between the photo-sensors of it's respective column. When the capstan wheel turned tape was either allowed into or pulled out of the columns, and the spool motor servo amps reacted accordingly. This meant that there was very little inertia thus allowing the capstan wheel to accelerate and reverse very quickly.
About the only thing that went wrong apart from drifting set points was the pea bulbs in the photo-sensors and carbon dust from the vacuum motor getting on the electronics. After VERY long mileage the tape heads would wear increasing the head gap and hence giving miss-reads. Oh happy days from my youth !!!!
About the only thing that went wrong apart from drifting set points was the pea bulbs in the photo-sensors and carbon dust from the vacuum motor getting on the electronics. After VERY long mileage the tape heads would wear increasing the head gap and hence giving miss-reads. Oh happy days from my youth !!!!
Andrew Mawson, proud to be a member of MetalworkingFun Forum since Oct 2013.