Re: Vacuum Tube "grids"

On Wed, 22 Oct 2008 20:51:17 -0500, "Jon Slaughter"
<Jon_Slaughter@xxxxxxxxxxx> wrote:


"Eeyore" <rabbitsfriendsandrelations@xxxxxxxxxxx> wrote in message
news:48FFD454.93CDEB34@xxxxxxxxxxxxxx


Jon Slaughter wrote:

Anyone know if essentially the design of the grids(gird, screen,
suppressor,
etc..) are virtually identical? i.e., could some application potentially
use
the suppression grid for the normal grid and the circuit still work if it
is
not too critical?

NO.

Their spacing is very important.


You guys don't get it. I don't care about the output. It is for an audio
project and and I am looking for different effects I can get which want
those different possibilities. I don't know how many times I have to say it.
I'm only concerned with the circuit topology used to drive the grids as
somehow having to be different or I'll end up fucking up the tube. But now
that I think about it it's quite obvious that the circuit topology can be
the same.

E = -phi_n+1 - sum(grad(phi_k)) - phi_0

where phi_k is the potential of the kth grid, phi_0 is the potential of the
cathode, and phi_n+1 is the potential of the anode.

phi_k might depend on material, temperature, geometry, etc... but since the
ultimate result is the potential(which is basically what I was trying to
ask) it doesn't matter. I just have to put a voltage across it and only make
sure I don't go over the current rating. That means that I'll get some
effect. THE TUBE MIGHT NOT OUTPUT ANYTHING but that is of no concern to me
as I mentioned I will be playing with "ideas". You guys seem to think I'm
going to randomly hook up the grids in some configuration for some
application then run it into mass production. You don't get that I am
simply going to play around with some idea(And it shouldn't matter) and see
what kinda outputs I get.

What is important too me is that I don't blow up the tube because one of hte
grids, say, happen to be created in a way that resonates at some frequency
and when I hook up my circuitry too it I end up hiting that resonance and it
creates an atomic explosion. I've mentioned many times before I'm not
interested in the signal output but the not ruining the components.

so, for you what works it's totally different from me. If I hook up
something to the grid and I don't ruin the tubes then it works... regardless
of the output. I guess this is a very difficult concept for people in this
group to comprehend but I guess then again they never "play around" with
circuit ideas and just copy *** out the book.



In your quest for vaccuum tube weirdness, look into the behaviour
of 6AR8 / 6JH8 / 6ME8 / 7360. These tubes use two electrodes that
steer the current between two adjacent plates. That allows you to
generate balanced modulation and other interesting effects.
Check this site: http://www.cgs.synth.net/tube/beam.html . Eric
Barbour has some interesting audio applications for some of these
strange tubes.
Check out the 6BN6, my old RCA tube manual doesn't say much about
it, but at heart it's a very weird little tube, and it's used for FM
quadrature detection, a neat little trick that was exploited in
probably millions of tube TV sets. Check out:
www.clarisonus.com/Archives/TubeTheory/6BN6_part_1.pdf and
www.clarisonus.com/Archives/TubeTheory/6BN6_part_2.pdf
If you thought tubes were pretty simple, the above articles will
change your mind! They play around with the "space charge".
There's a gold mine of info in the www.clarisonus.com/archives .
There are a number of vendors selling audio special effects boxes that
incorporate the 6BN6.

Paul G.
.