Re: Pentode valve TC (fwd) (singing spark) (fwd)

---------- Forwarded message ----------
Date: Sun, 12 Jul 1998 10:49:16 -0700
From: Jim Lux <jimlux-at-earthlink-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Pentode valve TC (fwd) (singing spark)

> Anyway, the sensitivity of the pentode suppressor and screen mean that
> i've got the full cct optimised, I should be able to drive those grids
> modulating waveforms: square waves at a few tens of Hz all the way
> to udio (singing brush etc. Just like Moses saw, I suppose).

You might look into the "ionophone". It was a plasma driven loudspeaker
essentially using a modulated CW brush discharge of sorts. Supposedly had
good frequency response (no heavy mechanical parts moving), but the
inevitable ozone raised a problem.