[TowerTalk] Jenning Capactior question

[Tom Rauch]

What I found is that instead I rotate the shaft there is no
change at the capacitance. Is this normal, maybe because
it´s the cap by itself?>>

If you grasp the capacitor body firmly and pull outward hard
on the blue area, the blue area should move outward like
working against a spring. That is the air trying to close
the bellows because of the vacuum in the capacitor. If it
does not do that, you may not have vacuum in the capacitor.

If you turn counter clockwise when the capacitor is fully
maximum the lead screw unscrews and the blue area gets
loose, and nothing changes with capacitance. If you turn
clockwise on the shaft many turns, the screw slowly pulls
the bellows out against the air pressure and the capacitance
slowly decreases.

73 Tom