Re: Meissner oscillator and Other VTTC circuits

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "David Trimmell by way of Terry Fritz <twftesla-at-uswest-dot-net>" <davidt-at-pond-dot-net>

Herwig, all,

I am in the thought stage of writing a introductory article on VTTC's,
primarily because there really is not much info available on this
subject. Much information is available on old valve based radio
engineering principles, but for the novice just wanting to construct a
VTTC, many of these principles can lead to confusion and feeling
overwhelmed. Vacuum Tube Tesla Coils appear to be a novelty of radio
engineering, I am interested in their history and any applicable uses
(aside from *just* making sparks). Some people on this list must know the
history of the various circuits used as VTTC's? I am also interested in
schematics of the various circuits that have been used, as the Hartley
(sp?), Armstrong, etc. If anyone can help me out here, I would be very
appreciative. 

This is a project that I do not see completion before this Summer, as time
is short for myself. Any help would be most usefull. If amyone wants to
help, let me know by personal e-mail. I am just starting on a outline of
the document, and will start with a introduction to Vacuum tubes and brief
history of their uses, especially as circuits close to modern VTTC's. I
will post the outline when completed. Any comments/sugestions welcome.

Regards,

David Trimmell
www.ChaoticUniverse-dot-com

On Fri, 9 Feb 2001, Tesla list wrote:

> Original poster: "Herwig Roscher by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <herwig.roscher-at-gmx.de>
> 
> 
> Dave Sharpe wrote:
> 
> This type of oscillator is known as a Meisner Oscillator in that the 
> LOAD is resonant.
> 
> Dave,
> 
> Some background information:
> 
> Alexander Meissner, born 1883, was the first to publish feedback 
> circuits, which produced undampened electromagnetic oscillations:
> 
> 1. Series connection. Plate current flows through tank paralel 
> circuit.
> b. Paralel connection. Plate current flows through choke and tank 
> paralel circuit is coupled to plate via capacitor.
> 
> 3. Of course it is possible as well to wire the frequency determining 
> components into the control grid circuit e.g. by paralelling the grid 
> coil by a capacitor. In this case no tank capacitor is used. This 
> circuit is a modification of the standard Meissner oscillator circuit. 
> The drawback here is that the output power is smaller, because 
> there is no resonant rise in the plate coil. Therefore this 
> modification is used as local oscillator in receivers mostly.
> 
> Mark Rzeszotarski has built such a small VTTC which produced a 
> 1" brush.
> 
> Opposite to the common oscillator circuits like Colpitts and Hartley 
> (which are improved 3-point-circuits), the Meissner oscillator (AKA 
> Armstrong oscillator) is a 4-point-circuit.
> 
> Unfortunately I could not find any information mentioning that 
> Meissner oscillators presuppose untuned control grid and plate 
> circuits but a resonant load instead. I would assume that the very 
> interesting experiment (no frequency splitting!!) David Trimmell 
> performed could be done with other oscillator types as well.
> 
> Comments and critics are always welcome.
> 
> Regards,
> 
> Herwig
> 
> 
> 
>