[AT] OT:(now tv)

[Jerry Rhodes]

Ken, I have some tubes if you need some, NOS ol'd ham radio days
Jerry NW Ohio KB8MAF

----- Original Message -----
From: "ken knierim" <wild1 at cpe-66-1-196-61.az.sprintbbd.net>
To: "Antique tractor email discussion group" <at at lists.antique-tractor.com>
Sent: Sunday, January 29, 2006 12:56 PM
Subject: RE: [AT] OT:(now tv)


>   Funny how a lot of this "old technology" has been forgotten. I've been
> working on a project that pretty much requires tubes. The original
> control system, developed in the late 30's or early 40's is based on a
> tube design. Another outfit tried replacing the older technology with
> new, solid state designed stuff, and it wouldn't work right.
>   When we got the project, the stipulation was to use the original
> design and build replacement parts to keep the original system
> operational. They have all the test equipment to keep the old systems
> running... tube testers and a mockup of the system so everything can be
> tested individually. It's a rather complex mechanical and electrical
> system and I can see why the folks trying to replace just parts of the
> system would have issues. I also got to learn and in some cases re-learn
> some stuff about tubes in the process.
>     After learning how this system works, I have to say that my hat's
> off to the great engineers that made this type of thing work (at least
> 20 years before I was born!). We take SO much for granted these days
> when designing stuff... I see what they went through to control a motor
> closed-loop on an aircraft. Transformers and motor-generators and phased
> control of a motor. This would be a good teacher of control systems
> theory colliding with the limits of available technology.
>     It's a turbosupercharger controller. I have taken an old
> point-to-point wiring design and put it on a circuit board for the
> amplifier. It goes on radial engines used on some 4-engine aircraft used
> during WWII. It's a walk through history and technology.
>
> Ken
>
>
> On Sat, 2006-01-28 at 19:42, Dean VP wrote:
> > Ralph:
> >
> > Yep, I remember the test patterns and the test tone. No 24 hour TV like
we
> > are so used to today. I also remember the waiting period for the tube
based
> > electronics to warm up. Solid state electronics changed all that.
Remember
> > the service men that would come out with their container of replacement
> > tubes, etc? And their tube tester!
> >
> > I started designing solid state based circuits in 1962 in industry after
> > being primarily trained in Vacuum Tube theory. The improved performance
and
> > significantly improved reliability was so pronounced that I consider it
one
> > of the major milestones in technology development. If the consumers
knew,
> > when the first TV sets came out, how close they were to potentially
failing,
> > no one would have bought one. It is a bit amazing how well they worked
in
> > their time.  But then servicing equipment was accepted. Today, if a
piece of
> > electronics fails it gets thrown away.
> >
> > Dean A. Van Peursem
> > Snohomish, WA 98290
> >
> > Forbidden fruits create many jams!
> >
> > www.deerelegacy.com
>
>
>
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