These ground spring contacts seem to have an odd way of not showing up
in exploded parts diagrams.
For instance, my 7L14 has a spring washer that presses against the
shouldered hex nut and the aluminum core of the REFERENCE LEVEL ring,
and yet there is no mention of it in the instruction manual. I am fairly
certain that it is factory original.
My 7A18 is a late serial number (>B140000), and has the two pairs of
ground contacts, but no springs or washers under the VOLTS/DIV knobs.
Is yours an early serial number? Does it have the ground contacts?
Dan G
