Archived - Farnsworth inner grid assembly

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Richard Hull
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Archived - Farnsworth inner grid assembly

Post by Richard Hull »

I have achived these two images as historical items. I have left them fairly large for those looking to see detail.

You are looking at the the most complicated inner grid assembly made by the Farnsworth team. There is a ruler for size comparison.

This insert includes tungsten screens and was originally hung or mounted using the new processed Linde Sapphire Technology of the mid-1960s. These "standoff" rods, according to Gene Meeks, cost about $1000.00 each 1964 bucks. (half the price of a brand, new full sized, Ford Galaxie 500.

These images were taken and sent to me by Bert Pool. He found this item and other Farnsworth memorabilia at the Jeffereson County Idaho, "Pioneer" museum that he visited a couple of weeks ago.

Bert was the very first person to ever log in and post on the now ancient "Songs" bulletin board and notified me of its existence only a few days after the Perfesser hooked it up to his Farnsworth site there. This was Bert's only posting to the fusor site, to my knowledge. Bert is an old Texas Tesla coiling buddy of mine.

Richard Hull
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Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Re: Archived - Farnsworth inner grid assembly

Post by Paul_Schatzkin »

Now.. why didn't I think to post a picture of this cathode when I saw it in Rigby two summers ago? Damn...

I was in Rigby in the summer of 2003 to help the BBC produce a segment about "Inventions That Changed the World," one of which was, obviously, television. We filmed some footage at the museum that Richard mentions here, and I was absolutely astonished to see this cathode from a Farnsworth fusor sitting on a table there.

See, this cathode (inner grid) is central to PTF's approach to fusion. I talked about it at some length a couple of years ago with Kent Farnsworth, who, believe it or not, has a "Hirsch" version of Pontiac Street vintage fusor in his garage.

I am attaching a photo of the cross section of the Hirsch fusor from when we opened it up in the spring of 2001. It is important to note the difference between the inner grid in this fusor and the inner grid in the Bert Pool photo:

Hirsch's grid is a solid stainless steel ball, with small openings only to accomodate the beams from the ion guns. The shell is otherwise impervious. Once the ions etc are inside this grid, nothing is going to get out.

The Farnsworth cathode/grid, on the other hand, is deliberately designed and fabrciated to be as penetrable as possible. There are discrete openings for the ion beams, as with the Hirsch cathode, but there are also large, screen-meshed openings all over the sphere.

These openings are important... critical, really, for the way Farnsworth envisioned the fusor would work. These openings are for the protons that fusion produces, so that they can be propelled against the anode shell, the outer shell of the fusor.

These positively charged particles are important because, as I understand it, they "work" against the positively charged anode, and this is how electricity is produced directly from the reaction. These protons represent half of the output of every fusion reaction, and if those particles are not allowed to do their job (as would be the case with the fully enclosed Hirsch version), then you are in effect losing half of the output of your process.

As I understand it, that half of the output is critical because it represents the energy that is "recycled" to keep the reaction going.

I'm very sorry I did not think to upload the picture of that cathode when I first saw it the summer of 2003. Anyway, here also attached is one of the pictures I took of it then, where you can clearly see the stainless steel screen mesh what covers the large openings. Also attached is a picture of the cathode in its setting in Rigby. Obviously, they had no idea this item has nothing to do with television. They have no idea what it is....

I might be off in some of my grasp of the principals at work here, but I do think that this cathode/grid is an important part of the discussion.

--PS
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Paul Schatzkin, aka "The Perfesser" – Founder and Host of Fusor.net
Author of The Boy Who Invented Television: 2023 Edition – https://amz.run/6ag1
"Fusion is not 20 years in the future; it is 60 years in the past and we missed it."
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Richard Hull
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Re: Archived - Farnsworth inner grid assembly

Post by Richard Hull »

Good stuff here Paul! Thanks for your contribution to this image archive of Farnsworth material. Both Paul and I have a lot of Farnsworth images that we will dole out over time. Some are property of the University of Utah archieves and can't be posted. Other's that we have are from private, personal image collections of Gene Meeks, George Bain and Steve Blaising from personal polaoids, slides and the like. On these, we have permission to use as we see fit.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Re: Archived - Farnsworth inner grid assembly

Post by DaveC »

Great pictures, Richard and Paul -.... Thanks very much.

It was a posting of Bert Poole's on a Tesla Coil site that led me to find the Songs Fusor site.


I am rather intrigued with these electrodes, that they have almost no attention to details of stress control and etc.. lots of sharp edges... right by the screens.

One thing I have seen is the lens openings cause severe aberrations to focus... when edges are thick and sharp cornered.

I am still planning to build up a lensed electrode that will not intercept the ion beams... at least the incoming ones.

Dave Cooper
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Re: Archived - Farnsworth inner grid assembly

Post by Richard Hull »

Yes, there are sharp edges which would distort the field real close to them, but these things operated at about 10e-6 torr and the ion gunned versions were differentially pumped as are most gunned devices. So corona or energy loss was not an issue. There is an old fractional disturbance rule of thumb about field distortion in and about a sphere. I can't remember it off hand, but there is a distance off a sphere that you can produce a lobe or projection that, if small enough, will not ostensibly alter the field from a near perfect sphere.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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