Electromagnetic waves and attenuation

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Discussion Overview

The discussion centers around the propagation and attenuation of electromagnetic waves, particularly in the context of radio and television signals. Participants explore the factors affecting the distance these waves can travel in the atmosphere and reference historical instances of long-distance transmission.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant inquires about the distance electromagnetic waves can travel and the attenuation they experience in the atmosphere, referencing historical transmissions by Marconi.
  • Another participant notes that the topic falls under classical electrodynamics and suggests searching for resources on radio and television signal propagation.
  • A different participant expresses difficulty in navigating the information available online regarding signal attenuation and requests alternative suggestions.
  • One participant shares a historical anecdote about a BBC TV broadcast in 1938 that was transmitted to New York under unusual atmospheric conditions.
  • Another participant mentions that short wave radio waves can bounce off the ionosphere, which enhances their range, particularly at night.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the specifics of electromagnetic wave propagation and attenuation, and multiple viewpoints and experiences are presented without resolution.

Contextual Notes

Some limitations include the lack of comprehensive resources identified by participants, the dependence on atmospheric conditions for signal propagation, and the unresolved complexities of signal attenuation in different contexts.

Who May Find This Useful

This discussion may be of interest to individuals studying classical electrodynamics, radio and television signal propagation, or those involved in improving digital TV reception.

dervast
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Hi i am trying to understand how long a electromagnetic wave can travel... What is the attenuation that the electromagnetic wave face in the atmosphere... This question arised when i have read that marconni at the beginning of 20th century has sent electromagnetic waves from england to canadA! How long the electromagnetic wave can travel in a free space model?
 
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This is really in the domain of classical electrodynamics, not quantum physics, by the way.

Propagation of radio and television signals is a very practical subject and has been extensively studied. Try a Google search on "radio signal propagation" and "television signal propagation" and you'll get many useful links.

I've gotten interested in this subject myself recently, because I'm one of those old-fashioned people who gets TV "over the air" from terrestrial broadcasters, rather from cable or satellite, and I've recently switched from analog TV to digital TV. I'm in a "deep fringe" area where most TV transmitters are over 50 miles (80 km) away. I want to improve my digital TV reception, so I'm starting to study signal propagation, antenna design, etc.
 
Thx a lot but i think if i search in google about signal atenuation i will get a headache with all these info ... Can u please suggest me sth else?
 
Well, I'm just starting to look so I haven't found anything comprehensive yet. I did find this just now, though: a BBC TV broadcast from London in 1938 that was carried to New York by freak atmospheric conditions and filmed off a TV screen by engineers at RCA laboratories!

http://www.apts.org.uk/recording.htm
 
Short wave radio waves bounce off the ionosphere, which greatly increases their range. This is more effective at night, which is noticeable even for long radio waves.
 

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