This past Friday I tracked down some RFI that has plagued Justin (N9TTK)
for a long time. The RFI was the typical every 1 second (approximately)
tick tick tick sound of an electric fence and it's present on all the MF &
HF bands. When close in I could also hear it up on 6 and 2 meters. Sure
enough I tracked the RFI down to an electric fence 0.33 miles from Justin's
QTH.
When I had isolated the problem to one of two nextdoor properties using my
portable flag I then switched to my VHF handheld in AM mode with a rubber
duck antenna and attenuators to narrow in on the signal just based on
signal intensity as my VHF AM radio with portable 4 element yagi and
attenuators still had difficulties pointing toward a peak or null when in
close which was probably due to the fence being so large in size (large
area) causing it to not look like a point source noise.
I just uploaded a brief youtube video that documents this case and here is
a link to the video for those interested. Youtube Link:
https://youtu.be/eqwN26YJzc8
Justin will now attempt to work with the property owner to clean up the RFI.
Notes: Justin lives in an area where there are many different sources of
RFI and in this case my portable flag was invaluable compared with my tuned
loops. The bidirectional properties of my tuned loops made it very
difficult to even validate my portable flag results using my tuned loops as
the electric fence RFI was often getting masked by noise arriving from the
rear direction when using my tuned loops. My portable flag continues to be
a life saver in my RFI DFing activities and it saves me an
unbelievable amount of time.
I should also note that the portable flag still provides about 10 dB of
front to back ratio up on 6 meters even though I advertised that it works
from 1.8 to 30 MHz as well as down in the AM broadcast band and in this
recent case I did briefly use it on 6 meters but I had to remove the DX
Engineering preamp as its gain really rolls off above 30 MHz.
73,
Don (wd8dsb)
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