- #1
- 243
- 15
I am looking for a very simple and specific vacuum tube. It doesnt have to be high power. I only need a plate that completely surrounds the cathode. No grids would be ideal. Anyone have a parts number or link for something similar to this?
Any diode such as 6AL5. Or maybe use a triode and connect the grid to anode. Then 6C4 or 6J5 would be suitable.I am looking for a very simple and specific vacuum tube. It doesnt have to be high power. I only need a plate that completely surrounds the cathode. No grids would be ideal. Anyone have a parts number or link for something similar to this?
why this requirement ... considering most are such ?I only need a plate that completely surrounds the cathode.
well if it has a grid, it isn't a diode !No grids would be ideal
a slightly rough way to do it, specially when there are many purpose built rectifiers out thereAny diode such as 6AL5. Or maybe use a triode and connect the grid to anode. Then 6C4 or 6J5 would be suitable.
Now I have a question. How do anode voltages accelerate the emitted electrons if the plate surrounds the cathode? From my understanding, anything inside a conductor is uninfluenced by electric fields produced by the conductor. Do the plates truly surround the cathode?why this requirement ... considering most are such ?
well if it has a grid, it isn't a diode !at minimum it's a triode
Dave
I am looking for a very simple and specific vacuum tube. It doesnt have to be high power. I only need a plate that completely surrounds the cathode. No grids would be ideal. Anyone have a parts number or link for something similar to this?
Am I the only one who finds the above quotes by the same person a bit odd?Now I have a question. How do anode voltages accelerate the emitted electrons if the plate surrounds the cathode? From my understanding, anything inside a conductor is uninfluenced by electric fields produced by the conductor. Do the plates truly surround the cathode?
What is odd about them?Am I the only one who finds the above quotes by the same person a bit odd?
because of the big potential difference between the plate ( anode) and the filament (cathode)Now I have a question. How do anode voltages accelerate the emitted electrons if the plate surrounds the cathode?
totally different situation, doesn't relate to what is happening in a tubeFrom my understanding, anything inside a conductor is uninfluenced by electric fields produced by the conductor.
Probably. It is an external electrostatic screen or metal envelope. The plate or anode is, a.In this pin layout, is M connected to ground?
The cylindrical plate structure is connected to a small top cap, well away and isolated from the pins, marked as p on the diagram. The black bump at the bottom of the diagram is a locating index on the base socket.This is from the 1b3gt tube dlgoff posted. Which pin; if any, is that metal cylinder wired to?
Thank you very much. This is exactly what I was looking for. Back to pin M in the layout. Does it stand to reason that I could turn on such a tube with a negative anode so that the electrons are attracted to the electrostatic screen? Then they would charge up the outer surface of the screen. Is this all reasonable?Probably. It is an external electrostatic screen or metal envelope. The plate or anode is, a.
The cylindrical plate structure is connected to a small top cap, well away and isolated from the pins, marked as p on the diagram. The black bump at the bottom of the diagram is a locating index on the base socket.
The slender filament heated cathode is mounted on a central axis. The tubular anode plate surrounds the cathode, so the heat due to the accelerated electrons impacting the inside of the anode, can be radiated from the larger area of the tubular anode, outwards through the glass envelope.
Electric fields close to the cathode are critical to electron emission. For a triode, the control grid is placed very close to the cathode. The fields inside a capacitor or coaxial cable are all internal, similarly, the electric fields between the cathode and the inside of the tubular anode of a vacuum tube are self-screened which reduces the effects of external electric noise and so reduces interference with other nearby components and signals.
It was Lee DeForest who first investigated the triode amplifier. He discovered the effect when placing an antenna wire against the outside of the glass envelope of a thermionic diode that was being used as a wireless signal detector. It became his “Audion” in 1905.
It is lucky he was not using a tubular anode electrode, but something more resembling the separated anode “plate” still used in tube diagrams.
if the plate is negative, then the electrons from the filament (cathode) will be repelled and the tube wont workDoes it stand to reason that I could turn on such a tube with a negative anode so that the electrons are attracted to the electrostatic screen? Then they would charge up the outer surface of the screen. Is this all reasonable?
But this tube has an indirectly heated cathode. If I connect the cathode and the anode to the same negative potential, wouldn't all field lines will end on the screen connected to M?if the plate is negative, then the electrons from the filament (cathode) will be repelled and the tube wont work
not sureBut this tube has an indirectly heated cathode. If I connect the cathode and the anode to the same negative potential, wouldn't all field lines will end on the screen connected to M?
Quiet source of high voltage dc current with very simply circuitry. My electrostatic generator is very loud and flybacks need smoothing caps etc.not sure
I see absolutely no point in doing that ??
Quiet electrically or acoustically? Audio noise is usually generated by physical movement in magnetic components. Magnetostriction in a magnetic core or movement of windings on the core can often be a problem.Quiet source of high voltage dc current with very simply circuitry. My electrostatic generator is very loud and flybacks need smoothing caps etc.
Avoid the word “screen” as that refers to an internal grid close to the plate. The black circle, M, in the diagram is not strictly an electrode. It may be a metal sleeve inside and/or outside the vacuum envelope.Back to pin M in the layout. Does it stand to reason that I could turn on such a tube with a negative anode so that the electrons are attracted to the electrostatic screen? Then they would charge up the outer surface of the screen. Is this all reasonable?
I agree, I'm only hoping for 100 volts. But, do you agree this could work? It will be fun to test anyway.Surface leakage across the glass base, or voltage breakdown between the pins will severely limit the voltages possible.