Topband: skew path

Tom Rauch W8JI@contesting.com
Thu, 27 Sep 2001 09:43:55 -0400


> >4.  JAs were coming in also, but on normal heading (270).  The area
> >that did the skewing was evidently farther away than the 2 hops to
> >JA.
> 
>         Same for me from Colorado.  I NEVER recall hearing JA's on 160
>         
> other than the direct 315 degree path to JA.  Only stations between
> 330 and 30 true could be worked on the 210 degree path.

JA's on many occasions arrive here from southwest paths early in 
the openings, and while they generally have more QSB than on the 
direct path they certainly do not have flutter. It is common to see 
an opening via both paths, with different fading rates.

VK6HD regularly shifts around on any direction between SW and 
NW, and even the eastern VK's move around a bit. VK3ZL between 
SW and W with occasional openings to the NW not only for Bob 
but also even for ZL3REX! Today during the high activity Mike and 
VK3ZL were both dead west.

Yesterday (when VK3ZL was reported NW in W5 land) Bob was 
due west to slightly south of west both just before his sunset, at 
my sunrise 1100Z, and after my sunrise he shifted slightly south of 
west.

I've watched the aurora levels and A and K indices, and have a 
difficult time finding any correlation between solar activity and 
signals...let alone propagation in general on 160.

A word of caution. It takes a fairly large array and a good signal to 
measure skews of 45 degrees or less with any reliability, unless 
you are using pattern nulls. With 350 feet of broadside antenna 
spacing, I can resolve about 20-30 degrees of shift without resorting 
to interferometer techniques. I really don't believe a single Beverage 
would be accurate at less than 45 degrees of skew when you 
consider the wide response angles. We have to be very careful, 
especially when signals are weak. We might be nulling the noise 
more than peaking the signal when we change directions!!!


73, Tom W8JI
W8JI@contesting.com