This may be a case where the marine DF receiver succeeds, and a
simple DF loop fails.
With the simple DF loop one is unable, repeat, *unable* to resolve
the __180 degree ambiguity__ that the 'null' of a simple loop gives.
The BIG, and this is NO slight advantage offered by the marine DF
receiver is the utilization of a "sense" antenna that works in combination
with the built-in loop antenna to 'synthesize' a cardioid or unidirectional
antenna pattern.
WITH THIS feature one can actually 'sweep' around the compass rose
and get a feel for where the strongest noise is coming from, like pointing
a Yagi antenna around, but on 160 or 80 meters! On the other hand, the
simple loop can ONLY give a one a NULL, and there remains the choice
of which direction, which bearing the 'source' lines in, because of that
180 degree ambiguity.
Also with the simple loop one cannot 'scan around' for the strongest
signal, whether that signal is a 'broad band' white noise (LIKE I get
from a car wash in my area) OR impulse 'buzz' noise from power
line arcing sources.
IT REALLY IS pretty cool to 'twirl' the direction knob on one of these
Coastal Navigator Marine DF receivers and HEAR the different 'arc'
signatures or sounds coming from different directions.
Maybe this is where we're getting hung up up? All my DFing for
any noise nowadays makes use of the marine DF receiver with the
sense antenna and that directional Cardioid pattern.
If IT emits, its a simple matter of taking two bearings sufficiently
spatially spaced apart and "x" marks the spot of the source. I now
use Google maps and 'null' bearings taken from my DF receivers
to pinpoint distant sources.
One technique I've used too is to 'set out' after one of these sources on
my trail bicycle, and through the use of null DFing and the Sense/Cardioid
function eventually locate OR determine the source is further way than
first thought. If I get down the road a mile or so AND the DF receiver is
still indicating the SAME direction, I'm looking at a source that is now
on the order of 4 to maybe 5 miles way, and as I've written, I've had a
couple just like that!
de AA5CT
.
.
On Saturday, January 11, 2020, 9:03:04 PM CST, Kenny Silverman
<kenny.k2kw@gmail.com> wrote:
KC4D,N3AC and N3CW went hunting with a KX3 and a DX Engineering Amplified RX
loop and again didn’t find anything conclusive. Basically they said the loop
performed about the same as one of the AM radios we have that’s fairly
directional.
We’ve been looking so many times that we’re getting frustrated. There are a
few noisy clusters, but we can’t find a specific pole or house. Nor can we
assess if the noisy areas are actually the key offender(s)
Do we call in the clusters we found ? Or do we really need to pinpoint the
source(s) better before we ask for crews to come out? We’re concerned about
crying wolf and/or giving a list of more than a dozen poles for the power
company to look at.
Regards , Kenny K2KW
P.S. the only success so far is fixing my subject line typo 🤓
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