18 Jan
2015
18 Jan
'15
2:31 p.m.
The horizontal width on my VT101 needs adjusting, so I
am in need of a
monitor alignment tool (PN 29-23190-00). I have tried searching the web to
see if I can found out what they look like so that I can improvise something
but I have failed to find a picture of the DEC one. Does anyone have a
picture of one? Is it just a long thin screwdriver? Is it the same as a
generic monitor alignment tool like this one:
http://eu.suzohapp.com/product/H92-0196-00/universal-monitor-alignment-tool-
kit? Even so the picture on that site makes it hard for me to tell what I
need to improvise something.
Never try to adjust a ferrite core with a metal tool. You _will_ (not may) end
up cracking it and causing more problems. Not to mention of course, the fact
that the metal tool will affect the inductance anyway [1].
IIRC the width coil on the VT100 has a hexagonal hole in it. The tool is a plastic
rod with a hexagonal end (there are only a few common sizes). There is nothing
AFAIK special about the DEC one. People have made them by filing plastic rod from
a model shop or a plastic knitting needle, but I think you can get the right tool
[1] At one time there was a tool which consisted of a plastic rod with a ferrite slug on
one end and a copper slug on the other. Putting the ferrite slug into a coil increased the
inductance, putting the copper slug in decreased it. So you tried each end in turn in a
coil
if there was improvement you knew the coil was off-tune and which way to tweak it.
-tony