Meissner oscillator

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

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