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| Author |
Message |
mark
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DXing physics
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Jul 12 04:06 UTC 2007 |
I don't really understand the physics involved in dxing. The atmospherics
the ionisphere, and all that. could someone explain?
--mark KI6DJZ
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| 9 responses total. |
krokus
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response 1 of 9:
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Jul 16 05:18 UTC 2007 |
This isn't a simple and quick subject, as propagation has a lot of
variables that need to be taken into account.
Start with this page:
http://en.wikipedia.org/wiki/Radio_propagation
Then follow the links of interest there.
You didn't specify if you wanted more information on AM Broadcast,
Shortwave, or specifically ham HF DXing.
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ball
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response 2 of 9:
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Jul 19 17:48 UTC 2007 |
I often listen to the radio in my car and noticed recently that at
night I can hear many more (and more distant) AM (medium wave)
stations than I can during the day. During the day, is the D layer
absorbing signals from the other stations, or merely reflecting
signals from stations less far away because it's lower than the E and
F layers?
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krokus
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response 3 of 9:
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Jul 19 18:27 UTC 2007 |
The D layer absorbs the signals, which is why the lower HF
frequencies, and MF frequencies, don't propagate well during
the daylight hours. When you can hear an AM Broadcast station
during the day, it is from the groundwave.
This is also why those stations must reduce their broadcasted
power, and HD Radio isn't allowed, during local nighttime.
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ball
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response 4 of 9:
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Jul 19 21:03 UTC 2007 |
That makes sense then. Interesting point about medium wave
HD Radio btw!
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krokus
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response 5 of 9:
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Jul 25 19:54 UTC 2007 |
I just read, in Popular Communications, that the FCC is
possibly going to allow HD broadcasts at night. There are
people not happy with that possibility.
This really makes me wonder about the decision making processes
the FCC has been using, between this and the whole BPL issue.
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ball
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response 6 of 9:
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Jul 25 23:22 UTC 2007 |
Decision making process: "Right, who's going to give us the
most cash?" ;-)
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krokus
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response 7 of 9:
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Aug 1 15:14 UTC 2007 |
Surely you're not suggesting our all-knowing Federal regulatory
agencies would be seduced by the all-mighty dollar? How dare
you, sir, how dare you.
</sarcasm>
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tod
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response 8 of 9:
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Aug 2 06:24 UTC 2007 |
*snort*
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ball
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response 9 of 9:
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Aug 7 04:07 UTC 2007 |
<grin>
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