OK, while we are on the topic another very big factor to think about is
magnetic north vs. true north (I have tried to not bring this up in the
past). I don't expect any response to this, but this has always been in
the back of my mind and wonder what headings are really being reported
(what is the reference, magnetic north or true north that each station is
using when he reports a heading).
The best procedure is to use multiple stations with known locations to
calibrate, and use a movable null.
For example, if I use a DXE NCC-1 as a combiner for interferometer use, I
can calibrate from W1AW and other ham stations in that general area. I can
then easily resolve directions that are just 2 degrees apart in heading at
that distance.
Without that, just using the eight circle, I cannot really resolve middle NY
from eastern Mass.
I think as the FCC becomes less and less involved, and as their DF sites
continue to deteriorate, hams may have to pick up their own system.
The important point of this is that bearings have tolerances, sometimes very
wide tolerances, so any plots should look like V's with ranges rather than
lines.
The best thing is always to get data from people with right angle lines,
especially those close to the problem, and to look at the plots based on the
real resolution of each plot. Some might be 120 degrees wide, and very few
will be narrower than 20-30 degrees.
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Topband Reflector
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