LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #11   Report Post  
Old May 9th 10, 08:13 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Oct 2009
Posts: 707
Default What exactly is radio


"K1TTT" wrote
...
On May 9, 10:30 am, "Szczepan Bialek" wrote:
"tom"
se.net...



On 5/8/2010 2:04 PM, Szczepan Bialek wrote:


Yes. But one end of the dipole may have the better conditions to
propagate.


if it only moves in one direction as it would have
to in a monopole there is no wave only a simple field.


I am writing about a dipole with one end visible and the second
shielded.


In nature is always as you wrote. The both ands are always "visible".


Light is always directional. Radio waves can be omnidirectional.
Of course light is emitted by many dipoles. Radio waves by halve, one,
two
(circular polarity) or many (phase radar).
S*


Astonishing understanding of the subject.


Light is not coherent. So dipole radiate for very short time.

Radio waves are coherent and can be from one source. It is easy to analyse
them.
Are they transversal?
S*


light can be coherent, what do you think lasers are?


"The most monochromatic sources are usually lasers; such high
monochromaticity implies long coherence lengths (up to hundreds of meters).
For example, a stabilized helium-neon laser can produce light with coherence
lengths in excess of 5 m. Not all lasers are monochromatic, however (e.g.
for a mode-locked Ti-sapphire laser, ?? ? 2 nm - 70 nm). LEDs are
characterized by ?? ? 50 nm, and tungsten filament lights exhibit ?? ? 600
nm, so these sources have shorter coherence times than the most
monochromatic lasers". From:
http://en.wikipedia.org/wiki/Coherence_(physics)

Up to now light is not coherent. But in future who knows.
S*


 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT +1. The time now is 11:09 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017