[TowerTalk] Arrival angles and sunspot number

[k6ll@juno.com]

On Tue, 25 Apr 2000 10:32:15 -0400 "Tom Rauch" <w8ji@contesting.com>
writes:
> 
> > >But Pete, you have me confused. What is an isotropic source with 
> > >gain, and how can you have one near earth?
> > 
> > It's like an uggerumph, I suspect.  In VOACAP, it is called a 
> "constant
> > gain isotrope."  If you could see it, it would look like a perfect
> > hemisphere with equal gain in every direction.
> > 
> > The beauty, of course, is that it adds no biases to the 
> propagation
> > prediction at all, other than whatever amount of path gain you add 
> at
> > either end.  No nulls at very low angles, or above the first lobe, 
> to cut
> > into the received signal strength at those angles.  
> 
> Great! Now I see.
> 
> What did that do to the wave angle predictions?
> 
> My ARRL Antenna Book uses the "inverted V dipoles at 100 ft" 
> antennas (which are really like a regular dipole at maybe 70 foot) 
> for predictions for 80-30 meters.  
> 
> Is the newer info available somewhere without buying a new book?

The new files are on the ARRL web site somewhere, which happens
to be trashed by hackers this morning. I think they are located
under support for the YT program, if I remember correctly. Search
on YT?

If you tend to operate on the highest frequency band that is open,
as single-op contesters frequently do, then it may be better to
use the older files, except for ten meters. I think the new ones
include some high angle statistics that occur only when you are
operating far below the MUF.

Dave Hachadorian, K6LL
Yuma, AZ
K6LL@juno.com























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