Vacuum tube Definition and 28 Threads

I am a freshman in highschool and I plan on building a linear particle accelerator (DTL) I need help finding out how to find the drift tube length. I use the equation V=√(2eV/m) (where V is equal to the velocity. E is the elementary charge of the electron 1.602 x 10^-19. V is the applied...

i.e a vacuum tube. using the gate in a triode to adjust the amplification of the electrons. i guess you would have to have a photographic plate attached to the anode but this shouldnt effect the operation of the valve. just a thought... not sure where you would put the detector, maybe it would...

Hey all, So if a gas is combusted, would it travel faster through a vacuum tube or a regular ole' tube? I would assume the vacuum tube, as there are less particulates collisions in the way of the fast-moving gas molecules. Yet this also implies pressure on the outside of the thin barrier _ 2...

Dear Sirs, After my theoretical post on vacuum diode electron flow, I decided to try and measure it physically. I didn't have a vacuum tube, so I improvised with some tungsten wire, aluminum sheets and some screws and the result was usable. Obviously the tungsten wire fails after some time due...

Dear Sirs I have been going through the "radiotron designers handbook", but I can't seem to find the answer to the doubt I have about the electron flow of the source Vp. Kindly consider the below two circuits, the difference is the polarity of Vf. Question: In both circuits, the electrons...

Homework Statement This problem is belonging to a book, which is material for Vietnamese students who will take part in IPhO (International Physics Olympiad). Since this problem is written in Vietnamese, I will try my best to translate it to English: A vacuum diode consists of two parallel...

Hello For the purpose of the experiment, I wonder what the maximum dimensions can have a transparent tube, I thought over a diameter of 30cm and a length of 1-1,5m and from what material should such a pipe be made. I would like to get a high vacuum (about 0,2-2Pa)

This is my first try at building everything myself. Programming the G Code to cut the chassis on my old Linux computer took a bit of thinking...lol Here is a short video. A few photos so far. I will post the schematic when I finish it. Cheers, Billy

Hi, Here is the schematic link: http://www.classictubeamps.com/schematics/Mesa/Mesa%20Boogie%20Solo%2050%20Rectoverb%20schematic.pdf The 12AX7 inverter tube has a measured plate voltage of 416 VDC just like the schematic indicates. V1a rail voltage is 394VDC with a 200K plate resistor and a...

Hi, Here is a typical data sheet for a commonly used 6l6GC tube. http://www.drtube.com/datasheets/6l6gc-jj2003.pdf Under typical characteristics (in this data sheet) a value of Ra and Ra-a are given. I assume Ra-a means Za-a and it could also be written as Zout. Is this a correct assumption...

I recently got an older tube amplifier , since ti was dirty from being left for a long time in an old shed i took the covers off and cleaned it , now I am listening it also with the covers off , everything works etc. Now I wonder do tubes at lower voltages and lower frequencies such as in the...

Hi Guys, I am having issues trying to repair this amp. http://www.tangible-technology.com/schematics/fender/HR-Deville/Hot%20Rod%20DeVille.pdf A little history is in order I guess. I have not been working on guitar amps for too long, several months now. I have repaired perhaps fifty or so...

I've been reading up about vacuum tubes and (more specifically) the Audion, and how they were used for instruments/amplifiers. This isn't anything I'm learning about on my degree, just things I'm reading up on myself so forgive me if I'm a little slow to grasp some parts. I understand how the...

What factors determine the anode plate-to-grid capacitance? I know that the capacitance of a regular capacitor is determined by the surface area of the plates and is inversely proportional to the distance between them. Does this hold for vacuum tube grids and anode plates? The reason I'm asking...

Here is my single triode vacuum tube amplifier circuit I understand there needs to be a bias on the grid otherwise the signal will be rectified -not amplified. Is biasing the grid as simple as running a resistor in-between the grid and the cathode on the power supply like this (in red)...

Someone on another forum shared with me that a 6L6 vacuum tube exhibits a blue dot when in operation that is supposed to be Cherenkov radiation. I say nay, as I have worked out the relativistic velocity using $$KE={ m }_{ 0 }{ c }^{ 2 }\left[ \frac { 1 }{ \sqrt { 1-\frac { { v }^{ 2 } }{ { c...

I would like to find an easier way to build spice models from old data sheets. Normally one would have to tediously build spread sheet tables from curve traces of these old tubes. However, I was wondering if there is some sort of program that allows one to trace lines over the images, set...

Hello. Here joined is the schematic of a small deflection amplifier. Outputs H0 & H1 are connected to electrodes placed in a vacuum volume. These outputs are protected by varistors. High voltage to collectors is 200 V DC. Sometimes, not very often, the head Op-Amp (LM324) is burnt. The only...

I know the default library of LTspice don't have vacuum tube model. Does anyone know where I can get one. If not, any other free spice program have vacuum tube models? The only one I find so far is: http://www.duncanamps.com/technical/ltspice.html I tried to follow the instruction and...

Old CRT tv's use vacuum tubes and they get hot, but how does the glass get hot when the inside is under a vacuum and therefore shouldn't transfer any heat?

How would a curious young gentleman like myself go about supplying power to a Mullard vacuum tube? I have several different types of Mullard tubes, but no idea as to how I can generate the electron beam. P.S. If side-effects of solution include death, injury or Hannah Montana please do not post.

If you have a tube with no air in it, making the the tube a vacuum. And stuck one end in space and the other end in the Earth's ocean. Then Opened both ends. Would it suck all the water out into space? If not what would happen?

So... let's say I wanted to drop a pipe on the ocean floor with a 6" inner diameter... which has a pretty strong vacuum in it... what general size/material do you suppose that would require... assume it is miles long. I guess you could keep the vacuum pipe inside of another pipe that does not...

Hey I was just wanting to know, for something like a guitar amplifyer what is the inputted signal connected to on the valve (cathode, anode, filament or grid) and also what the outputed signal is connected to. thanx

Hi all! OK, hopefully this will be a very quick question. Basically, I want to know how to model a vacuum tube (both triode and pentode) in terms of creating a dynamic system model. For example, if were to look at the voltage in an inductor as a function of time, I would employ the relation...

It seems that amps using vacuum tubes are becoming more and more popular with musicians these days. They're a bit expensive, at least the models I've seen, and the claim is that these vacuum tube amps produce a better sound or a richer sound. I was wondering if there was a physics-based...

Hey all; None of my EE classes cover vac tubes since they're largely obsolete. The thing is, for my senior design project (I have a year or so, no rush.) I'd like to build an audio amplifier. From experience I know the advantages of vac tubes and am willing to put up with the drawbacks...

in which I could fit about a 3" diameter object in. I have searched and searched all over the net and I can't find any. I would like to purchase a vacuum tube so that I could do several experiments on what happens to household objects in a vaccum. I would like to see how ice changes in it among...