Cathodic ray Emmisions. i need a plain expanation to a plain question.

[baroutologos]

Hello,


Ok without having experimenting with this concept, i believe with certainty 99% that Arthur's Salady concept cannot work.


Connecting a Vaccum Tube aplifier's the hot filament to the cathode (maybe grounded), and the grid to an High voltage Anode, thus having acceleration of the electrons through vaccum and the "collecting plate" to a load and then to the cathode, we have:


potential from Cathode to Anode = HV and
from Anode to Plate = - HV - voltage drop accross load.


Can work such thing? I mean electrons are attracted from the cathode to the ANode with the SAME magnitude and maybe less than repelled from the non-thermionic emmisive plate to the ANODE.
Does thermionic emmision would play any role?


Nevetheless it would be a cool experiment.
***

@void,

I envy you that you had the chance to have hands on experience. Still you noticed a tiny.. plate current to cathode? Interesting..
If i was about to replicate the experiment, i would have divised full current control in the HV circuitry, allowing adjustable say 0,5 - 5ma current to flow from filament to Grid. (adjustable. Controller will regulate HV potential donw to 0v say)

Grid is quite fragile and of low power dessipation. Is nothing hard actually to make, just an oscillator to a HV tranformer (rectified) and a small circuitry with sense resistor controlling duty cycle of oscillator.

Even someone can play with cathode's filament power and make observations of any current coming from plate.
***

Generaly the Tetrode 4-400A is a medium to High power valve with the technology of the space screen to anhance and extend the electrons cloud from thermionic emmision.
If the simple core of the effect works, it should be found (even feebler) in Triodes too,i.e. plain filament cathode, grid, anode.

It is not necessary to spend a fortunate to have some on hands experience. just you need the right controlling input circuitry to investigate if there is any effect at all.

***

cheers,
Barou


ps: cool experimenting but does not answer the fundamental question. where the energy should come from?

[Void]

Hi baroutologos. I was able to regulate the HV DC supply from a few hundred volts
up to several thousand volts DC by varying its supply voltage, but only saw a
small voltage on the plate across the load resistors even with the HV set to produce
close to 5 mA grid current.
All the best...

[baroutologos]

Hi baroutologos. I was able to regulate the HV DC supply from a few hundred volts
up to several thousand volts DC by varying its supply voltage, but only saw a
small voltage on the plate across the load resistors even with the HV set to produce
close to 5 mA grid current.
All the best...

Thank you Void for the reply.


Why that small voltage happened? Maybe from plate to grid direct electron cold cathode emission rather than "traveling electrons from anode hiting the plate" ?
What magnitude the current had about? mA? uA? nA? ANy idea about the potential? logically the same or less as th HV applied.


Any idea about the polarity in respect to heated cathode?


Sorry for my wording diarrea, but cant help it.


cheers,
Barou

[Void]

Hi baroutologos. I think when I first hooked things up, the plate voltage
went up to around +200VDC with the 6,600 ohms (nominal) connected to the plate, but there
were arcing sounds coming from inside the tube, and I think after that the plate
voltage would not go above about +40VDC or so, no matter how I adjusted the grid voltage.

Maybe my tube was damaged from the arcing. At around 200VDC, that would be a plate/load current
of about 30mA, and at around 40VDC that would be a plate/load current of about 6mA. So maybe it
did work as Arthur described to a small extent, but I think the internal arcing or another leakage issue
with the grid was  not allowing the grid voltage to climb above 400V or so, at least in my tests. It may
have been an issue with the tube I have, although the tube was brand new and I think Eimac is a decent
quality tube brand. 

[baroutologos]

Thank you Void, again, for your practical insights.


***
Actually, in my way of understanding, since the plate had always positive voltage (even in small currents) means that the Principle of Arthur is not existant.
I would be far more intrigued if the plate had a negative voltage (in repsect to cathode)


Positive voltage means lack of electrons than migrated from the cold cathodic plate to the HV anodic grid. So, the circuits closes as


majority of electron current rushes from hot filament Cathode --> HV Positive Grid
minor electron current goes from cold Plate -> HV Positive Grid


if it were to accelarate the electrons of thermionic emmission from Hot cathodic filament to anodic grid and by gaining velocity missing the grid and hitting the plate, by default the plate would have been more NEGATIVE in respect to cathode and circuit's ground. The experimental opposite find (i.e. a more positive plate) means everything goes as expected to go.


Thanks,
Barou