[SOC] In True SOC Style

[Fred Jensen]

daz at ft-817.co.uk wrote:
> 
> I've heard hams talking about the grey line before.
> I thought it was the mark you get on your neck when you haven't washed 
> properly.

That too, however it usually means the mark on your collar.  By the time 
the gray line appears there, your neck should be clean.

> You mean it has something to do with radio????

Yes.  The ionosphere is divided into layers which are very creatively 
name with letters.  I don't know if there are A, B, and C layers, but 
there are D, E, and F layers.  So far, news of a G layer has not made it 
out here to the American frontier that I know of.  The earlier in the 
alphabet, the lower the layer.  The F-layer bends signals back down to 
the Earth and accounts for all the distant babble we hear on 20m [and 15 
and 10 if there were any spots on the sun].  It is on top and we like 
it.  Unfortunately, it only appears when the sun is shining on it and so 
it disappears at night, accompanied by all the signals on 20.

The E-layer is similar to intelligence on TV, it comes and goes and only 
appears in small places at any time, and not terribly often.  When it 
has come, it accounts for longer distance signals on 6m and sometimes 
2m, and those ops like it a lot.  The D-layer is similar to a sponge, 
and it absorbs signals.  The lower the frequency, the higher the 
absorption.  It too comes with the dawn and disappears with sunset.  So, 
during the day, a 160m signal gets eaten up in the D-layer, and at 
night, it gets through but there is little left of the F-layer to bend 
it back down.  This is one reason why 160 and 80 sound fairly dead in 
the daytime [the other is because I left the dummy load connected to the 
radio].

At your dawn, the F-layer starts to build, and so does the D-layer, but 
more slowly.  I don't know why however my theory is that it is because D 
is earlier in the alphabet than F and the sun starts at Z just to keep 
us on our toes.  Now, if it is dawn for you, it is sunset on the other 
side of the planet [on most days].  There, the D-layer starts to 
disappear, but for some unknown reason [OK, unknown to me] the F-layer 
hangs around for a few minutes.  During this time [maybe 15 - 30 min], 
low frequency signals can get to the F-layer and bend down and extreme 
DX is possible.  Extreme antennas and extreme power help too.

I have heard this effect only once in 53 years of ham radio although I 
have listened for it at least 3 or 4 times, but I am assured that it 
occurs often.  If you're interested, I'll be glad to make up an 
explanation for tropospheric ducting too.  I know it has something to do 
with sticky tape.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2007 CQP Oct 6-7
- www.cqp.org