Re: Backlash/Play in the Delta Time Position Control on a 2236


On Thu, Dec 24, 2020 at 12:09 AM, Jeff Dutky wrote:

Exactly right about which control I'm talking about, but I'm a bit confused
about the service manual. I have the same PN for the service manual that you
indicate, but I can't find R1618/1619, and the delta time position pot is
labeled R1617, and indicates that it is only a single 2.2K pot. It sounds like
we have the service manuals for each other's scopes (mine is a much later SN
than yours, B027035). My SM appears to be the first printing from MAR 83.
I don't know where you've got your manual from. I looked through my own PDF and 4 PDF's on TekWiki. They all show the double pot in dwg 10 (K2 area is difficult to read). R1618 and R1619 also are in dwg 10 just to the right of R1617 and both are listed in the parts list. Different copies may have been made from manually updated originals.

The setup for the pots is the standard way that's often used: The two pot's ends in parallel and the runners connected to a common point through separate resistors. The common point becomes the virtual "runner".

Your 2336 was made in Beaverton, USA, mine in the UK, as can be seen from the starting "2" in my SN. There is no straight relation between serial numbers in different regions. This has been brought up and complained about many times in this group. If non-USA production didn't start until a few years after (USA) introduction, regional "early" numbers would cross to US high numbers. Not really a way to tell though.


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