Fun oscilloscope (filament transformer) was: Re: tube synthsizer

[Martin Czech]

:::I built a simple oscilloscope 15 years ago, with a very big oscilloscope
:::tube (22 cm across). Couldn't find a 6.3V transformer either, used a 6V
:::standard resin encapsulated black plastic "cube" instead. Works fine. Do 
:::check that the secundary and primary windings are insulated well enough 
:::against the voltages you use!! I generate the high voltage with a diode
:::and capacitor "ladder". Isn't that a circuit invented by Mr. Graetz...?

Wouldn't be such a bad idea to have a simple scope in a modular,
I remember there was a kit, but this is years ago. Perhaps better
to buy a cheap chinese or russian type, and fit it mechanically into
a new enclosure, or something like that.

Since the deflection is electrostatic instead of electromagnetic (like
in TV) I'd expect no moise/shielding problems...

I always thought that he invented the diode bridge rectifier...

btw.: Some tube circuits use DC heating, NS have a special regulator for 6.3V
for this very purpose. Other people say that this will shorten the lifetime of
the filament (electromigration?). Any experiences?

m.c.