Re: Marx generator (fwd)

["High Voltage list" <hvlist@xxxxxxxxxx>]

Original poster: <sroys@xxxxxxxxxxxxxxxxx>



---------- Forwarded message ----------
Date: Mon, 21 Nov 2005 22:09:28 +0000
From: GEORGE STEIN <afa2fg@xxxxxxx>
To: hvlist@xxxxxxxxxx
Subject: Re: Marx generator (fwd)

Howdy,
  Does the erecting of a Marx coil happen all at once or does one gap fire 
then the next and so on ?? Does anyone have a " short " video of a Marx in 
operation??
   With all the parts in one of these devices, It sounds loke a good winter 
project, making all the parts.

Thanx
George Stein

>From: "High Voltage list" <hvlist@xxxxxxxxxx>
>To: hvlist <hvlist@xxxxxxxxxxxxxxxxx>
>Subject: Re: Marx generator (fwd)
>Date: Mon, 21 Nov 2005 14:26:13 -0700 (MST)
>
>Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
>---------- Forwarded message ----------
>Date: Tue, 22 Nov 2005 09:07:51 +1300
>From: Malcolm Watts <m.j.watts@xxxxxxxxxxxx>
>To: High Voltage list <hvlist@xxxxxxxxxx>
>Subject: Re: Marx generator (fwd)
>
>Hi Herwig,
>
>On 21 Nov 2005, at 11:55, High Voltage list wrote:
>
> > Original poster: <sroys@xxxxxxxxxxxxxxxxx>
> >
> >
> >
> > ---------- Forwarded message ----------
> > Date: Fri, 18 Nov 2005 13:11:52 +0100
> > From: Herwig Roscher <herwig.roscher@xxxxxx>
> > To: hvlist@xxxxxxxxxx
> > Subject: Marx generator
> >
> >
> > List,
> >
> > I have just finished building my first Marx generator and I am about
> > tuning it.
> >
> > Capacitors			3.33 nF
> > Resistors			2 MOhm
> > Stages 			25
> > Loading voltage	20 kV
> > Spark gaps		0.28"
> > Erected C			133 pF
> > Bang voltage		500 kV
> > Bang size			16 Joule
> > Discharge length	13.4"
> >
> > However I would like to ask the more experienced builders for some
> > help:
> >
> > Q1:
> > The distance, a voltage of 1 kV can jump, usually is said to be
> > 0.013". For Marx generators I found values of about 0.04" as well.
> >
> > Other Marx builders claim:
> >
> > 0.052"		Rapp
> > 0.045"		Steve Ward
> > 0.052"		Kronjaeger
> > 0.050"		Mike Gilchrist
> >
> > My system jumps only 0.027"/kV. Why? Is this a question of the form of
> > the electrodes?
>
>I built two some time ago. The caps were about 7nF each, dry-fired
>rolled poly. In theory, mine should have been 250 - 300kV when
>erected. The uncertainty is in the gap firing voltage/s. I got about
>7" sparks. I was using chokes instead of resistors for charging.
>Total energy was about 14J.
>
> > Q2:
> > Other Marx builders get:
> >
> > 1.75"/Joule		Rapp
> > 1.92"/Joule		Steve Ward
> > 1.83"/Joule		Mike Gilchrist
> >
> > I only get 0.9"/Joule. Again: Why?
> >
> > Q3:
> > During and after completion of the bank loading there is no sizzling
> > noise. Therefor I assume, that there is little or no corona at 20 kV.
> > Is it possible, that at ignition of the bank there is too much corona
> > at 500 kV?
> >
> > What are the secrets of Marx tuning? Any help would be appreciated
> > very much.
>
>Gap settings are rather critical. Ideally the it should erect from
>bottom to top. I didn't bother with triggered gaps.
>
>Malcolm
>
>
>