Off topic - the birth of Television

[Graham Meredith]

If anyone is interested, here is a website dedicated to the inventor of Television, Philo T. Farnsworth:

http://www.farnovision.com

Fascinating reading, tells of his idea as a 14 y.o. boy, to project and transmit motion pictures by radio waves, its development, his struggles to patent it and perfect it, and his legal battle against RCA to protect his patents.


Graham

[Jerry Jones]

Jerrold Jones

Yes - he grew up in Rigby, Idaho... not far from where I attended high school (St. Anthony, Idaho):

http://www.farnovision.com/chronicles/tfc-part01.html

As a high school student, I remember driving through Rigby, a small town, and feeling both proud and amazed that the father of television had grown up there.

[Brian Ellis]

Gawd Almighty! How to rewrite history! Please note that in the pre-history section there is no mention of the real pioneers like Nipkow and Baird, nor of electronic flying spot scanning of photographs that pre-dated Zworykin (this was working about 1920 with c 200 lines non-interlaced). This technique was eventually developed into the Telecine machine which the BBC had in service in 1936 when they started their electronic TV service from Alexandra Palace on 45 MHz. It translated 35 mm 24 x 18 mm image size cine film into a 405 line interlaced image, 25 fps. The main problem that bugged Zworykin in the early days was keystone correction due to the angular attack of the photosensitive surface by the electron beam, and maintaining the focus of the latter over the range of distances.

[Dave Lawton]

For a good potted history of the beginnings of Television have a look at an article from the EBU at

http://www.dvb.org/news/framesets/docs_present_fr.html

then select the History of Television (pdf file)

Dave

[Brian Ellis]

Dave

I quickly ran through the first part of the doc you mentioned and it certainly fits in well with what I learnt when I was at college in the late 1940s (I did a course in TV technology). In fact, it reminded me of some things I had forgotten.

I made a semi-mistake in my earlier post. The original Telecine scanned by mirrors on the periphery of a drum, from a mercury lamp. This scanned a frame twice, but the pull-down in the short frame-synch time was so brutal to the medium that a film was torn to pieces after a couple of passages. This was then replaced by just a few mirrors which simply did a line scan, the vertical movement being supplied by a constant motion of the film at 25 fps: I'm not sure how they did interlacing with this: possibly by scanning two successive frames. It was only later that a CRT was used as the light source. This was done by having a double-height interlaced raster on the screen and pulling the film past the focussed image at constant velocity, so that it was scanned correctly. This was done in the 1930s when the first photomultiplier tubes were marketed. I believe the specially developed CRT used was a 5" diameter, electrostatically deflected, one, operating at 5 kV, using a phosphor which was matched to the spectral sensitivity of the caesium photomultipler. The lifetime of these tubes was short, I believe about 10 hours, because the phosphor got itself "burnt" at the high electron velocity needed to provide sufficient light. Sorry for the misunderstanding!

[Dr Mordrid]

Farnsworth may still have his place in history, although too late for him to enjoy it.

One of his last ideas was a fusion reactor design.

Most fusion research has been using either the Russian tokamak (toroidal) magnetic confinement design or laser implosion. This situation has been static for decades.

Way back in the 1950's Farnsworth proposed that the best way to do fusion was using a spherical electrostatic containment. His concept was called the FUSOR.

With the help of a physicist named Robert Hirsch, hired in 1964 to refine the design, a small FUSOR achieved an output of 10 to the 10th neurons/second in 1967. The entire device fit on a dessert cart and pugged into a normal 20 amp outlet.

Unfortunately the old Atomic Energy Commission ignored his work and eventually the FUSOR was relegated to private experientation.

Hirsch went on to become director of federal fusion research for four years and served as Vice President of the Electric Power Research Institute. To this day he cannot understand why the FUSOR, and other simple and easy to test confinement designs, were and still are ignored. Special interests that may not really want fusion to come online, perhaps?

Still, the FUSOR is again being tested, this time by multiple teams using deuterium-deuterium reactions.

Daimler/Chrysler Aerospace, working with the U. of Illinois, are working on a portable neutron source based on the FUSOR design.

A team at Los Alamos is actively working on a fusion reactor design based on the FUSOR.

Another team is being funded by the US Navy. The operational statement from the Navy is "you can't put a tokamak on a ship"

Image of a working FUSOR built by an amature scientist using readily available materials;



Yes, it produces a neutron flux.

One can only imagine what could of come from a Farnsworth/Tesla collaboration.

Dr. Mordrid