Re: [ARSCLIST] Repairing (or purchasing) a Uher

["Nigel Champion (FOA ANT)" <n.champion@xxxxxxxxxxxxxx>]

Richard L. Hess wrote:
>> Does anyone who has a slow speed Revox happen to know what the
capstan diameter is?
>> I'm wondering if that is turned down from the standard 3.75/7.5 A77
capstan. If it 
>> isn't that would bode well for the A77/B77 and A810 to be running at
slower speeds.
>> All these use the Studer AC servo motor. I wonder what its real lower
limit is.

We have several Revox A77/B77s at different speeds.  As well as the
capstan diameter being reduced for lower speeds, the casting of the
capstan motor is drilled offset.  This maintains the angle between the
pinch roller and the capstan giving optimum "tape-wrap" of the capstan.


Swapping capstan motors is relatively easy on the B77.  However, two
capacitors on the speed control board need to be changed (for low speed)
as well as the EQ components on the reproduce amplifiers.  

>> I really get frustrated maintaining machines that are used 1-2 times
per year.
>> It's a lose-lose situation. That's why I try modifying my main
machines to handle
>> the outliers.

Swapping circuit boards, complete aligned head assemblies (full, half,
quarter) are all relatively easy on the B77.  However, tape handling is
not as gentle as on a Studer but you have to cut your clothes to suit
your cloth.

All the Best
Nigel

---------------------------------------------- 
Nigel Champion
Archive of Maori & Pacific Music