[AMPS] Vacuum Variable voltage rating

[W0UN--Signal Hill Ranch]

>
>A lot of the glass vacuum variables being sold at
>flea markets/E-Bay are 50 years old, or so.
>Caveat-emptor!


You can get a good idea of the vacuum by just grabbing
the drive mechanism and seeing you can pull it straight
out.  The same as reducing the capacitance but without
turning the screw.  A bad vacuum will be easy to pull--
only a couple of pounds of force max.  A good cap will
require 30 or 40 pounds of force depending on the surface
area of the bellows.  Makes for a quick test to see if you
should even consider a flea market special.

John  W0UN


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