In a message dated 2/6/2005 11:12:46 AM Eastern Standard Time,
david.kirkby@onetel.net writes:
>>Yet refraction of radio waves was understood well before 1980 when you
wrote that. A Quick look at 'Cornell University's School of Electrical
Engineering Publications'<<
I do not claim to "inventing" refraction. What I was trying to convey (with
my rough English) that there is perhaps more refracting - ducting going on than
just reflecting. Most if not all books at that time were showing way out of
proportion drawings of globe and ionospheric layers (too high) and "nice"
bouncy signals. Hardly any mention of ducting on HF.
After the article was published I got bombarded by mails, some saying that I
am nuts (it ain't so) and some that this is nothing new. I guess depends who
and how they look and interpret it.
Using my Razor antennas I was able to "see" some things that were not
generally known and I tried to describe them as best as I could. There is more
and
more stuff being confirmed about possible, lets call it "refraducting". See
Topband reflector about spotlight, skewed path and high angle propagation,
about
which I was ridiculed way back.
>>Non-linear effects can be seen in many materials, but generally need
high field strengths - not the sort of E or H field you could produce on
the iosphere with a transmitter on earth. At least that is my
"gut-feeling" - I may be wrong.<<
Call me old wife, but we have noticed that after the major contest, bands
seem to be "conditioned" to propagate better for a while, about half an hour
after the bedlam stops. I had numerous skeds with OK2RZ on 40m right after the
contest and our signals would take a dive after about 1/2 hour. While at other,
non-contest times, at the same time we did not see that effect.
If you consider really thousands of kWs and high gain antennas during the
contests, in view of now knowing about ionospheric heating (HAARP), I would not
completely dismiss the effect. There might be even selective "heat your own
frequency" effect.
Another interesting thing I experienced when trying to see if the same angle
on receive and transmit applies. By switching stacked Razors and doing RX/TX
tests my finding was that about 60% of the time it was not the same. Bite me
for that one :-)
When we are talking about "non-linear" ionosphere, we are implying properties
not exactly reciprocal, biderectional or behaving like a coax. Rather than it
is not simple mechanism and things could seem to be one way, weird signal
levels and the rest of it.
I haven't been "up there" and measured how the atmo/ionosphere works, only
able to observe some effects, results and trying to make some sense of it.
Again, I am pleased to see Rich's notes about 23 dB, however "inacurate" it
is, it supports rather than denies something that we observed.
That's why I still fool around with radios, we don't know everything yet :-)
73 Yuri, www.K3BU.us
www.computeradio.us home of Dream Radio One
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