6 Nov
2003
6 Nov
'03
9:50 a.m.
Ok, now it gets slicky ... Tony, you're maybe one
of the few
that can somehow proof me wrong, but I doubt that anybody
will come around with a homegrown 14" B/W CRT to replace a
damaged for any 1970s terminal I have, nor with any colour
CRT, not even a rather rough one like used in the IIgs colour
screen.
I don't doubt that it's possible with home grown development
and tools to build a diplay tuge able to show of something,
but from there, until todays CRTs is quite some way.
Making a CRT from scratch that is even remotely usable is probably beyond
impossible. Quite a few guys have made tubes in the basement, and the
best anyone can do is something on par with a 1920s triode. Maybe.
The problem is not so much the building of the guns or the bulb, or even
getting a good vacuum - it is *keeping* a good vacuum. Outgassing any
tube is a combination of proper materials, environment, and timing, with a
healthy dose of magic mixed in. It is far more than just pumping out the
gas, sealing the tip, and popping the getter. The tube may work
initially, but in a very short amount of time you might as well start
over.
Most of this information is well documented, thanks to the Dowd archive,
but some of the magic is not, and is now gone along with the tube men. If
you look at all of the troubles restarted modern tube shops have - even
using the original equipment - you might be suprised. Even in the old
days, there was much "heartbreak" to get the bugs out. After making a few
thousand trial runs, quality tubes might start coming of the lines.
There is a very good article in a recent Tube Collector (yes, there is a
magazine for those that collect tubes) called "Heartache on the Factory
Floor", or something like that.
William Donzelli
aw288(a)osfn.org