--- On Thu, 2/24/11, Art Shifrin <[log in to unmask]> wrote:


> 1. speed (or speeds if there were two)

The standard speed for desktop units was about 30 RPM
(this is from memory, so give or take - after I return
from vacation I can measure one).  But there was also
a Dictabelt "Time Recorder" which had two machines
with common electronics, running at 1/2 speed.  They
would hand off to each other as long as someone
changed the finished belts.  They could be used to
record telephone conversations, and in that mode
recording was voice-activated.