O'Neill's Electronic Museum

Penn Valley California

Ferdinand Braun Cathode Ray Tube


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Braun CRT

Thought to be the Second of Five Made

Time line of Braun´s Work and Life

Eulogy for Braun.
Natural Sciences Magazine August 1928
Translation in Process

Forward (by Bern Dibner) from Friedrich Kurylo's
Biography of Ferdinand Braun.

(A very good biography of Braun, reprinted with permission)

Ferdinand Braun shared the 1909 Nobel prize with Marconi "in recognition of their contributions to the development of wireless telegraphy". While Marconi was tenacious and ingenious in the development of wireless telegraphy, it was Braun who hammered out the theory on the anvil of science. Some of the discoveries made by Braun and utilized by Marconi are:
  • Combining a Leyden Jar with an enlarged coil. Thus lowering the frequency of oscillation to a more manageable range.

  • Separation of the oscillator circuit from the antenna circuit to eliminated damping (of the oscillation).
    An example of this coil made by the Marconi company can be viewed here.

  • Adjusting the windings in the primary and secondary circuits to bring them in to resonance. One of the absolute necessities of modern radio!

While this is a very simplistic treatment of a complex subject I feel that F. Braun has received very little recognition (especially outside of Europe) of his contributions to wireless telegraphy. (As compared to Marconi) For more information I highly recommend Friedrich Kurylo's Biography of Ferdinand Braun. The forward can be viewed here.
Also it is Ferdinand Braun not Karl Ferdinand Braun or Karl Braun

Below is an actual Braun Cathode Ray Tube. Braun developed this tube at the University of Strassbourg starting in 1897. This is a cold cathode tube with only about one third of the electrons passing through a hole in the aluminum plate (between the anode and phosphor screen) and striking the phosphor screen. It requires 10,000 to 20,000 volts between the cathode and anode to operate.
It is interesting to note that Braun did not file a patent for this remarkable invention. He felt that it should be available to all scientists for research.

This certainly must have been an exciting time in the development of electricity and electronics. When Braun received a tube like this (or this tube!) at the University of Strassbourg it was received with great anticipation. Initially the tube only had a magnetic field applied on one axis rendering a vertical line on the screen. In order to get the full display the screen was viewed in a rotating mirror.

It is one of my personal dreams, if our museum becomes real as opposed to virtual, is to have a replica tube made. I would then absolutely love to set it up as it was around 1900 for public viewing.

Cathode (Cold) Braun CRT Braun CRT Anode

Plate with the hole for channeling electrons into a beam. Braun CRT

Phosphor Screen
Braun CRT

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