In article ,
Fredxx wrote:
First ones I saw in practice were on a Clerk-Technique pro 1/4" tape
machine. About 1970. The design later made by Levers-Rich.

Are you certain this wasn't a hysteresis motor?
https://en.wikipedia.org/wiki/Synchr...teresis_motors

Fairly certain, as that's what the guys who fixed them said. It was usual
in having twin capstans, and not relying on feed motor back tension for
the tape/head contact.

You're probably right but given the cost of electronics over brushes I
assumed BLDC motors would have been associated with satellites and other
high value items with a long design life.

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