Further 11/40 unibus questions...
lists at databasics.us
Fri Jun 5 17:46:48 CDT 2009
Tony Duell wrote:
> Sure. It is always best to look for the obvious things first (says the
> guy who once spent a long time fioguring out a low contrast fault on a
> VT100 video board, only to find the CRT screen needed cleaning...). But
> after a bit, it's best to attack the problem logically.
Long ago, I bought a Heathkit color television -- it was gorgeous.
Needed some work. Also, while I was contemplating buying it, the owner
offered to throw in a 'scope, too. It had never worked he said. The
screen was "grainy" and a new tube cost too much. I accepted. The
television was easy to fix (Heathkit, I said).
But, when I fired up the 'scope, I was shocked. He was right. The
scope image could be focused, but it never got clear. It looked like
the phosphor was painted on the tube with a roller. Then, I had to
I took off the bezel, pulled off the graticule screen, and peeled the
tyvek sticky paper off the back of the plastic screen, and voila! A
nice clear trace.
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