[R-390] Fw: Re: Lutefisk and The Ballast Tube Thread - on topic -Haa! - Take that

[Barry Hauser]

> I'm not real sure we know what the process was that they used to
> manufacture the ballast tubes.

Probably not too many possibilities.

> It's pretty obvious that precision wire placement and careful insulator
> assembly were not part of the process.

Yea But Dept:  There might be some plan to the apparent casual drape to the
filament.  Maybe some "knack" is involved.

We obviously have the skills to
> figure out the wire length, wire gauge, and wire composition they used.

Supposed to be drawn iron.  The trick is to get all those little curli-ques
into it.  Heck, keeps breaking when I just do one turn.  I suspect a diamond
edge potato peeler affair -- like a wood plane where the shavings come off
curled.

> No way are you going to convince me that anything closer than a 10%
> accuracy is needed in ether wire length or diameter.

I won't try ...

>
> If we send out a tube or two for a residual gas analysis we'll know
> what the gas mix they used was. The only other variable would be
> pressure.

Supposed to be either hydrogen or helium -- one way to find out:  Throw a
bad tube on the barbeque and see if it goes pop-flash, as opposed to just
pop .. uh nuthin.

>
> My guess is that they did a very normal bake out with a vacuum pump on
> the tubulation. Once the thing is clean on the vac ion gauge you fire
> up the wire with a constant current source. Then you back fill the tube
> to the point that the voltage on it drops to a specified value. More or
> less it's a thermistor vacuum gauge in reverse.

Sounds complicated.  Since these were filled with gas, was it necessary to
apply vacuum first.  Blast the gas through which would displace the air.
Question of whether it's cheaper to waste some gas.  Might be problematical
with hydrogen.  Probably assembled in a vacuum cage, then H or He sucked
into it.

>
> Once it's stable with a given gas level you can sweep it to check it's
> regulation. If it passes you seal it off.

Maybe on the prototype, but production runs?  Just assemble pins/rods, slip
on the micas, drape the required length of iron wire (with curlycues), weld
the ends to #2 and #7 pin, et.

>
> If the process is really that simple - why the high cost for these darn
> things? They never have been cheap. The process can't have been as
> extensive as a normal vacuum tube. If we have the skills to figure out
> the details then anybody in the tube business could have.  Again - why
> should these cost so darn much ....

Two reasons -- Virtual monopoly & the highly influential Ballast Tube Lobby.
(Sen. Joe McCarthy was merely a diversion.  "Y'mean you're gonna charge the
govament $50 bucks for a bulb that hardly lights up!"  " Shuddup and go
chase some comminists!"  "What if they aren't there?"  "Chase 'em anyway
udderwise someday when you go to start your car, there might be a trunkload
of free samples, with one wired to the starter switch!)

Hey, look - it could have happened that way.  Just keep watching the History
Channel for when it gets declassified.

Barry