Archived - From the Wayback Machine - Farnsworth dynode grid

Current images of fusor efforts, components, etc. Try to continuously update from your name, a current photo using edit function. Title post with your name once only. Change image and text as needed. See first posting for details.
Post Reply
User avatar
Site Admin
Posts: 739
Joined: Thu Jun 14, 2001 4:49 pm
Real name: aka The Perfesser

Archived - From the Wayback Machine - Farnsworth dynode grid

Post by Paul_Schatzkin » Fri Aug 17, 2012 3:18 am

Several years ago, I went to Rigby, Idaho, where the BBC filmed a segment about Farnsworth's "hayfield" moment when he conceived electronic television.

While I was there I visited the small museum that houses some Farnsworth memorabilia, and was quite surprised to find this remarkable artifact among the collection.

This is the cathode/grid from a Farnsworth fusor ca. early 1960s. It's an important design, because its purpose is both to have some heft to it AND permit particles - especially PROTONs, to escape the inner core.

I have no idea how such a thing found its way to Rigby... I tried to spirit the thing away but... alas, it remains there (so far as I know nearly a decade later...).
Cathode-DSC_0163_HDR.jpg (506.77 KiB) Viewed 2868 times
Paul Schatzkin, aka "The Perfesser" – Founder and Host of
Author of The Boy Who Invented Television -
"Fusion is not 20 years in the future; it is 50 years in the past and we missed it."

John Futter
Posts: 1670
Joined: Thu Apr 22, 2004 2:29 am
Real name: John Futter

Re: From the Wayback Machine

Post by John Futter » Fri Aug 17, 2012 4:09 am

A stunning example of the Instrument Makers Art

well done Paul

David Geer
Posts: 136
Joined: Wed Nov 24, 2010 12:51 pm
Real name:
Location: Colorado Springs, CO

Re: From the Wayback Machine

Post by David Geer » Fri Aug 17, 2012 4:34 am

Looks much like the Polywell structure. Might be what he got the idea from... yet another Farnsworth design.
- David Geer

Joe Jarski
Posts: 21
Joined: Tue Jun 01, 2010 12:52 am
Real name: Joe Jarski
Location: SE Michigan

Re: From the Wayback Machine

Post by Joe Jarski » Fri Aug 17, 2012 4:54 am

Nice photo! Probably the most detailed I've seen. It'll be helpful in my project.

User avatar
Richard Hull
Posts: 12496
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: From the Wayback Machine

Post by Richard Hull » Fri Aug 17, 2012 5:23 pm

This was actually used in the Mark III fusor design 1962-1964 that never did anything much! I have published the image of the MKIII here before under the heading of "warp drive core" The famaous fabulous looking flop. Also known as the "pit fusor" Truly an impressive piece of failed hardware.


According to Gene Meeks this was originally damaged (Tungsten screening burned up) and this example shown was a repaired spare dynode that was never needed, but kept in reserve. Steve Blaising, (Farnsworth team member), has a photo of this same unit with the screening burned out taken back in 1964.

It took Hirsch and Meeks new designs in the "cave" along with the use of Tritium in 1963-64 time frame to start making decent neutron numbers. This "dynode" pictured here is seen mounted on a metal stalk for display. In the real MK II, Farnsworth got Linde to grow and machine two pure sapphire insulating 6" long, 1/2" diameter stalks for this item. (Linde had only recently perfected flawless artifical sapphire and ruby boule growing techniques.) One of these precious stalks broke in handling and mounting the MK III and the other broke later as the device was beening dismantled. (curiousity - some of the broken pieces were made into jewelry for Pem Farnsworth)

It is with sorrow that I must announce the passing of Fred Haak one of the last surviving members of the original Farnsworth team. To my current knowledge the remaining survivors are only Steven Blaising and Robert Hirsch. I am fortunate to have personally met with and extensively interviewed all 6 members of the original team except for Phil Farnsworth, himself. ( I have also met and talked with Pem Farnsworth - wife - now deceased also)

All are passed away now except Steve and Bob who were only part of the effort in the last 4 most productive years of the team effort.


The Hirsch meeks fusor shown in the URL here produced over 10,000 times the fusion of the MK III !!!

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
Retired now...Doing only what I want and not what I should...every day is a saturday.

Posts: 105
Joined: Tue Jul 27, 2010 12:40 am
Real name:

Re: From the Wayback Machine

Post by Dustin » Mon Aug 20, 2012 6:41 am

I remember posting this "way back"
Looks like the same one "new"


Post Reply