12 Sep
2008
12 Sep
'08
11:18 a.m.
This is probably an old question but, well, I'm new to the list...
Is there a known substitute CRT (both mfr and p/n) for the tube that is
in a DEC VR201 monitor such as used with a DEC Rainbow?
I've never had t oreplace the CRT in a VR201, but my experience is that
small monochrome CRTs are pretty generic (there are 2 main families), and
from what I can find about the intenrals of the VR201
it's a very
standard monitor with normal-looking voltages on the CRT.
The 2 families are basically :
Narrow nexk with a 7 pin base (modified B7G -- modified in that the
sealing tube is in the middle of the pins)) and a 12V filament
Wider neck with an 8 pin base (B8H) and a 6.3V filament.
You need one of the former type. Oh, and it's a 90 degree deflection
angle. I've never seen a wider deflection angle in a computer terminal or
monitor, but some UK portable TVs had 105 degree CRTs that are not
suitable here.
The other issue is the mouting. I can't rememebr if the VR201 CRT has
fixing lugs on the tension band or not. Obviously you need one with the
same mounting arrangements. Do not, whatever you do, try to mofify or
remove that tension band!
But my guess is that putting any CRT that will physically fit in will
work. You may have to tweak the focus and G2 presets, that's all
I would not ne at all suprised if the CRT from a DEC terminal worked...
-tony