Topband: More 3W5FM, Reflector, etc.

[Bill Tippett]

Hi Tom!

        I'll save space and make comments on your original post:

W8JI wrote:

>I'm a little confused by the postings about longpath when the signal 
>is actually a skewed path.

        I've been working this path for over 40 years on 20, 40, 80,
and now even 160.  If you check Packetcluster postings any morning for
20 or 40 you will see it commonly called "long path".  You are welcome
to call it what you want but everyone I know calls it long path
even though it may not be the exact reciprocal 180 degree path you
are thinking of.  It's probably a difference in semantics that is
hanging you up but the common meaning of "long path" has is well-
established even if it might not fit a technically correct definiton.

>I think that is skewed path, not long path. I'm open to correction on 
>my thinking if someone can explain why a general southwest 
>direction would be longpath. Maybe I misunderstand what it 
>means, but I think longpath refers to the furthest possible straight 
>line path. 

        I prefer to use the term "skewed path" when severe ionospheric
disturbances skew the signals slightly (usually <90 degrees) from 
their true headings.  The two propagation modes are completely
different IMHO and that's why I would not use "skew" to describe long
paths (sunrise or sunset) that appear to skirt the full daylight circle 
over the South Pole during our winter months.
 
>Sunset at this end might be longpath, but it would not be possible 
>with or near full daylight at the south pole. More likely it would be a 
>skewed path, as commonly occurs with JA's in the evening during 
>our winters.

        It IS possible if the signal skirts the daylight area
over the South Pole.  If you look at a Great Circle map and look at
where full daylight is at this time of year, you will notice that it
fully covers the polar zone from approximately 155 to 205 degrees.
IMHO, the consistency of LP signals near these two bearings must mean
there is some sort of greyline launching mechanism that allows signals
to refract around the area of full daylight.  Just to illustrate this,
I worked more than 50 countries from Colorado on sunrise 80M long path,
geographically ranging from XW8 to OZ and they were consistently
coming from the same direction (~210 degrees).  Most stations from
the West Coast are very familiar with this path because that is how
they work most of the Middle East, Central Asia, and Europe on 80.    

        Furthermore, long path signals have a characteristically very
different sound than signals skewed by geomagnetic disturbances.  They
have a more fluttery, echoey sound to my ear.  The strange thing to
me is that I have seen instances where stations will come through 
long path one day and skew the next.  XZ1N even did it in the same
day at two different times (150 degrees around my sunset and 40
degrees around his sunrise...his true heading was 4 degrees).

>Wouldn't it be better if we saved the term longpath for real longpath, 
>and not bent paths?

        Maybe, but the path is most commonly called long path by the
guys who work it day after day on 20, 40 and 80 in the Western USA. 
When I use the term, I mean a path that is very consistent in bearing
at 210 degrees (my sunrise) or 150 degrees (my sunset) and which is
different from the skew paths caused by geomagnetic disturbances.  I
classify JA's coming from W or WSW during disturbances at our sunrise
or EU skewed E during our evenings in the latter category.  Maybe my
common usage of "long path" is arbitrary but I belive there are two
VERY different mechanisms at work and they deserve two different names.

                                                73,  Bill  W4ZV

P.S.  More boring details on the above are in a 1991 article republished
by the WWDXC in 1998 and available from K7LXC (proceeds to WWDXC and
not me, hi)

P.P.S.  My incoming E-mail seems to be working now but I know there is 
missing mail...please resend if you haven't seen your post or my response
to a direct message.


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