Braun Cathode Ray Tube
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Thought to be the Second of Five Made
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:
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
- Combining a Leyden Jar with an enlarged coil. Thus
lowering the frequency of oscillation to a more
- Separation of the oscillator circuit from the
antenna circuit to eliminated damping (of the
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!
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
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) Anode
Plate with the hole for channeling electrons into