[sdiy] box of tubes - mercury revisited

[René Schmitz]

Hi Antti and all,

> More than that, they're usually high power rectifier diodes. We're 
> talking about kilowatt power here.

Not necessarily.

> Normal tubes found in guitar amps and similar low power devices 
> shouldn't contain any mercury. 

But there are some variants of regular vacuum diodes, which were just 
beefed up by adding the mercury. (Not quite common in consumer gear 
though thats right, but not enough difference to distinguish them by the 
size.)

A nice gallery of some Hg rectifiers can be found here:
http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/GL-Roehren/HG-und-Gas-Gleichrichter/HG.htm
(But don't try it if you're on dialup, the guy put all pics on a single 
page. Consider yourself warned...)

The getters are usually barium (see
> http://en.wikipedia.org/wiki/Getter).

Sometimes also Zirkonium or Magnesium.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159