21 Jun
2004
21 Jun
'04
9:40 a.m.
You see, knowledge already lost. Yes, a magnetron has
a vacuum in it.
It has a filament and a plate ( with cavities in it ). While the
principles of these things can be found in books, much of the
mechanical and physical methods used to create these things is lost.
Please, people, please. Stop using the vacuum tube as an example of "lost
technology". It is a faulty example, at best.
We know "most" of the knowledge about vacuum tubes. We have most of the
*original* technical libraries from Eimac and RCA, and parts of many other
companies. We have the Proceedings of the IRE and other technical
journals. We have the research done by Tyne, who did it all while many of
the original tube guys (and tubes) were still around. We now have a
professional organization that does serious reseach on the history of
tubes. More stuff comes up every week. Basically, we know a hell of a lot.
For example, at the AWA TCA (Tube Collectors Association) meeting a couple
of years ago, we were all given a twenty-odd photocopy of all of the
Standardization Notices from RCA on how to make an type 45 triode. That
means ever last detail, down to what cement to use to glue the base to the
bulb.
I can think of NO glaring holes in our knowledge of tubes. The holes that
do come to mind are really relatively minor - details like how many 6N6Gs
Sylvania made during the fourth quarter of 1938, and did Triad ever try to
make Loctal tubes.
While it is claimed that the information is in books,
there
are some feel things that rarely seem to make it into these
books.
Yes, there is, and this is a problem. In reality, it tends to be a tiny
percentage of a given field's knowledge base. We should, however, strive
to fill these "feel thing" holes, as they are important.
Can anyone tell me what controls the gain of a vacuum
tube ( other than someone that actually worked with these )?
Can anyone tell me how the grids must be placed for an electrometer
preamp tube and why?
I think everyone on this list could find this information quite
easily. The knowledge is not lost.
William Donzelli
aw288(a)osfn.org