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I recently asked some questions about MUF, and I guess the summary is that
MUF-3000 is a point property of the ionosphere at a particular point and the
path MUF is the maximum, usable frequency from your location to a location
at which you want to be heard. For simple one-hop paths, the path muf is
related to (but not necessarily identical to) the MUF-3000 at a point
halfway to the destination.
Relevant to the above, I have a particular question about the DX Atlas
suite, which consists of DX Atlas, HAMCap and Ionoprobe. You can open Ham
Cap and in it select Ionoprobe and DXAtlas, and all three are coupled
together, Or you can open all three independently, and on HamCap press only
Ionoprobe. Now DX Atlas is connected directly to IonoProbe (it would be
even if HamCap were not open) and HamCap is connected to Ionoprobe but not
to DX Atlas. So under these conditions Ham Cap and DX Atlas are running
independently but are both using the live Indices from IonoProbe. You can
size the windows so that HamCap and DXAtlas are both simultaneously visible.
Now set DXAtlas to display MUF with live indices (from Ionoprobe). As you
move the mouse cursor, you will see that the readout gives MUF-3000 data,
which in "bright" areas was just over 30MHz this AM. Now go to HamCap and
do the same. You will see that MUF is shown, but it is not identified as
MUF 3000, just MUF. And as you run the cursor around you will see the
numbers are a lot lower than those shown on DX Atlas. The numbers also look
more like what I would expect to be the path MUF to the point under the
mouse cursor. As you move the cursor in HamCap you will see notation such
as 1F2, 2F2, F2F2 (any idea what that means) and other configurations that
describe what the program is assuming for the path from your station to the
receive path under the cursor.
But one thing is for sure: if you move the cursor to a particular point in
HamCap you will see a significantly different MUF number than that you will
see with the cursor at the same point in DX Atlas.
The documentation in DX Atlas and particularly HamCap is very limited. I
think Alex is so bright that he assumes things are so obvious that he
doesn't need to give detailed explanations. But my conclusion is that the
MUF displayed in the HamCap-Ionoprobe combo is the path MUF (along with an
indication of the path configuration) and that the MUF in the DX
Atlas-IonoProbe combination is MUF-3000 (as it is marked) and that for
one-hop F2 paths the point where the mouse should be placed is not on the
destination but on a point halfway there on a great circle path-which DX
Atlas will plot.
Is there someone on this reflector who has looked at these programs in
enough detail to comment on this?
By the way if you select both the IonoProbe and DXAtlas buttons in HAMCAP
all three programs are coupled, and if you open the Ionospheric panel in
DXAtlas you will see that user data is selected-which in this case does not
mean that you need to enter data manually but that DXAtlas is getting it
from the HAMCAP interface. In this case DXAtlas reports SNR information for
the path in question and generates an SNR contour or shadow map. This is a
very useful display. Under these conditions, as soon as you select another
ionospheric map in DXAtlas like MUF, critical frequency etc, the connection
through HAMCAP is broken, the User Data item is grayed out and cannot be
re-selected, and DXAtlas is directly connected to IonoProbe, just as if
HAMCAP were not open (to use the Ionoprobe data, live indices must be
selected).
Bob W2WG
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