[sdiy] here's one for all you eBay lovers

[metasonix]

>Interesting stuff.  I just cannot imagine actually hand making tubes.  Is
>this common place at all amoung tube lovers?

No, only a few guys have made replica Audions. But most only
did it as a hobby, and marked their creations clearly as
repros. Weingarten deliberately worked to make his tubes
look exactly like the originals. Then he sold them to stupid
radio collectors. Most of them didn't even work--his vacuum
system was a joke.

>> Among other problems here, thoriated filament wire was NOT used in the
>original Audions! It wasn't invented until 1920. Original Audions used
>tantalum wire filaments.
>An interesting fact that probably not too many people on the planet know.

Easily checked. Tyne's book (still in print)
SAGA OF THE VACUUM TUBE covers the whole story in detail.

>What's really the market for this kind of tube anyhow?  Are they really that
>sought after? 

McCandless only made a few thousand of them from 1907 to 1912. 
They were obsolete by the start of WWI--too much residual gas.
Most were broken or thrown away over the years. 

Today, an Audion with a good filament and capable of 
any usable emission can bring $10k or more (sometimes a LOT more).
Sleazy antique dealers copy furniture and art all the time. Now the
electronic world has things being copied. 
(looks like Moog modules are next...)

There are recent rumors of someone in Taiwan making fake Apple I PC boards.
Because the real ones are selling for $15k-30k.

>The glass blanks in the last picture look an awful lot like the molds
>for making those resin giant-bunch-of-grapes from the 70's.

Guess what--those "molds" were nothing but unfinished globe-lamp
envelopes. Which is probably what these "tube blanks" were.

Even at $1500 reserve, it's still not exceptional stuff. However,
some doofus might buy it, and try to make more Audions. He's in for
a shock when he finds out how difficult it was. He'll need a bake-out
oven or induction coil with a high vacuum pump, plus gas and compressed 
air, possibly a cryotrap and liquid nitrogen to put in it, plus a
resistance spotwelder....and lots and lots of patience.