As my good friend George AA7JV used to say Noise I UP!
I live is a city lot, 20 years ago it was in a rural area, now it is in the
city, The man made noise is exponentially going up. In 2006 I bult a
vertical WF with great directivity, FPL , our local power and light company
did and does a great job fixing power light noise. I had a good time
enjoying it, big problem was Plasma TV, but it is gone now replaced with new
OLED or equivalent screens.
2010 I built a horizontal HWF, the idea was to use polarization as a filter,
manmade noise propagates only vertically polarized. I can check my notes
comparing both antennas and at the beguine their were even, after 5 more
years the vertical WF become useless due the amount of manmade noise.
Now, the main problem here are solar panels and EV. Electrical vehicles are
very noise but not a problem on the, when the get home and the owner plug
the charger into a big power supply the noise become an issue form 500kHz to
30 MHz, every 100 kHz there is a cluster of noise. 1800, 1900, 2000 etc.;.
Two EV generate two clusters but close together, not exactly on topo of each
other. Solar panel noise goes always after Sun Set.
Another "thing" growing up is noise from indoor LED growing plants lamp.
These are really a big problem here on 14 MHz and 3.5MHz.
My point is the we need new solutions to fight noise. My horizontal HWF is
at its limit here. Just polarization filter is not enough anymore , It was
necessary to detune the tower holding the HWF. The HWF at 60 FT with a 43db
gain preamp was generation s6 to s7 on the S-meter with 600 Hz BW CW. After
detuning the tower the noise is now s0, with some switching noise that the
NB can remove it.
The keep with noise going up, we need to take some difficult actions to
avoid common mode noise. Doing the same is not working anymore.
This video was made for a friend to see the test of the HWF at 60FT , not a
good production, but give the idea how it works.
https://youtu.be/IyXXFkuPZZQ
73's
JC
N4IS
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