Karl Ferdinand Braun's Nobel lecture

held on 11 December 1909


In 1909, both Ferdinand Braun and Guglielmo Marconi shared the Nobel Prize of Physics


Ferdinand Braun's lectured was called:

Electrical oscillations and wireless telegraphy


Keywords (briefly): In accepting today the great honour and privilege of addressing the members of an Academy ..... ; In the Autumn of the same year (1897, AOB), Slaby, using much the same arrangment, reached 21 km over land but only by means of balloons to which attached wires of 300 m  .... ; Why must one ask was it so difficult to increase the range? ... ; I set myself the task of obtaining stronger effects from the transmitter ... ; What facts were at our disposal and what conclusions could be drawn from them? ... ; in fact Feddersen had already directly photographed up to 20 half-cycles of oscillations in 1862. ..... ; Considering the greater amounts of energy which can be collected and stored in suitable experimental form in capacitors one could expect to deliver radiated energy for some time from them ... ; three circuits arose from this, which I described as inductive and direct transmitter excitation .... ; The set-up is now unsymmetrical due to the proximity of earth ... ; But as far as the spark resistance was concerned my fears as M. Wien has recently shown were without foundation ...; The difficulty was to so couple circuits of this kind together that they all start to discharge at the same moment .... ; By my arrangements so-called coupled systems were introduced throughout in the wireless telegraphy system  ..... ; Now Oberbeck in 1895 demonstrated the following by calculation. If a capacitor is allowed to operate inductively upon a second circuit of the same natural frequency there appear most strikingly two oscillations in both circuits .... ; This result also hold for mechanical systems ... ;  shall call them briefly beating (or pulsating) oscillations. Just such curves would arise if we allowed our pendulum to write upon a moving plate ... ; The thing is clear to the mind of the tuning fork example ... ; These electrical oscillations can be separated by means of a variable capacitor circuit the so-called resonance Leyden-jar circuit ... ; Through the combination of a Köpsel's calibrated variable rotating capacitor and a number of calculated self-inductances .... ; The theoretical investigation was most effective in clearing the problem basically .... ; I found in 1902 that an antenna inclined at somewhat less than 10° to the horizon formed a kind of directional receiver ... ; Pierce by means of the cathode-ray tube has demonstrated for slow oscillations an almost complete separation of positive and negative components ..... 

The rest is dealing with aspects on directional antennae even the  cardioid-antenna-diagram was discussed. Also something on his semi-conducting detector  



Regard also, or proceed with: Braun's whisker detector diode patent  of 1906

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