how and why.
i know that if an air particle becomes an ion and then accelerates towards the cathode it will damage it. does the negative bias give the particle an electron stopping bombardment of the cathode?
or is it something else???
Hi the cracken,
I 'm afraid you don't know anything about electronic tubes.
These are the principles of electronic tubes:
The (heated) cathode emits a cloud of electrons searching their way to neutralize. The anode is (normally) positively charged attracting the electrons.
So far so good. Hope you understand this.
An electronic tube does not contain air particles, but is a vacuum tube with almost not containing air, but argon, a gas isolating electrons as also used to weld stainless steel.
If there is no grid (charged with a fixed or variable negative voltage) the electrons will flow directly toward the anode (charged positive) and take care of an unlimited current flow between cathode and anode, depending on the cathode to produce free electrons.
This is good for a rectifier tube, but not for a controlled AF-amplifier.
To control the electron flow between cathode and anode the grid must be charged with a negative voltage to slow down the flow of electrons, hence controlling amplification, like working as a brake.
The grid is also commonly known as "control grid" or "steering grid".
Each electronic tube has its own characteristics and the best bias voltage for its application should be selected carefully for best performance according to data sheets, may it be for a class-A class-B or class-C amplifier.
This is the best information I can provide for you. If you're not satisfied you better google for principles of electronic vacuum valves.
Regards
Boncuk
P.S. Are you Norwegian?