On the Emulation of TU58s

Chuck Guzis cclist at sydex.com
Tue Jun 16 13:20:54 CDT 2015

On 06/16/2015 11:08 AM, Henk Gooijen wrote:

> The round (approx 2" diameter) "bearings" of the TU80 do not rotate.
> Instead, the metal has tiny holes. Air pressure pushes the tape away
> from the bearings. As the tape moves, due to movement pressure, the
> tape comes closer to the air bearing. That is measured. To get the
> air pressure back to some sort of equilibrium the pickup or supply
> reel speed is adjusted.
> That is how I understand the mechanism ... now writing this down, I
> think I should read up the Theory of Operation chapter ...

Pretty much the standard CDC vacuum-column design since the 1960s.  The 
TU80 is, after all, a CDC product.  Two counter-rotating capstans--tape 
movement is determined by applying positive or negative pressure to 
ether or both (i.e. positive pressure on both results in the tape "floating"


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