My coil winder is from the 1920s and no manual and when I picked it up in a
very sorry state, it was minus the tensioning aparatus, so never seen.
This ETA hand winder is something like the Avo Douglas coil winder but the
manual for that is not very helpful on picture or description, being part 30
lost in this pic, 50K
http://home.graffiti.net/diverse:gra...t/douglas2.jpg

I made up a workable back tensioner from VCR slip clutch, lightly sprung
pulley carrier etc but it is not very good for evening out the variation
due to unwinding very light gauge wire from the supply spool giving a
somewhat jerky back tension. It is many years since I was hands-on a Douglas
and have forgotten what the mechanism is. Anyone know what the Avo system is
or any other more reliable system. As far as I remember it was a pair of
discs that somehow the wire passed through and the pressure between the
discs was varied for different tension. I also seem to remember that it too
was not very good at the very lightest gauge wire AWG40 / SWG45 and it was
better to run through human fingers rather than the discs. At only 1 or 2 oz
back tension it would sometimes grab onto the wire if contaminated or
something and break the wire. But there must be better than human finger
back tensioner.
Is there a 2-stage spool supply process? so the wire is unwound to an
intermediary stage at near enough zero tension that then goes to the winder
?