One of the noise sources was when an electrician had installed a set of LED LIGHTS in a display case window. The noise was so bad 2 summers ago that 160,80,40,30 were virtually useless. 40 meter noise was 60 over s 9. Then found out what the problem was....the LED power supply. the power supply is a linear power supply when turned on as it warms up,the qrn increases. Then at night, the front desk lady would shut them off about 11:30 pm and about 5:45 am I would hear a pop and BUZZZZZZZZZZZZZZZZZZZZZZZZZZZ @ 60 OVER! So I removed that linear power supply and went to a switching and there is still a little noise, but it is now only s 3 to 5 s units. When I park my car right next to the hotel,near the computer station,( mobile antenna is a LITTLE TARHEEL ) the noise level is 0 to s 2.
Man-made noise isn't vertical, but men and their noise making apparatus are at ground level and vertical antennas have low take off angle and "see" these apparatus at close distance. Higher angle antennas see further away man-made noise at first skip, but the inverse square law reduces these in intensity considerably.
GOOD SITE AND ARTICLE FOR VERT INFO. VERTICALS ARE TO SOME DEGREE, BETTER FOR DX DUE TO HIGHER TOA. BUT THERE IS MORE NOISE TO BE HAD AT HIGHER TAKE OFF ANGLES. CHECK OUT THIS SITE FOR A GOOD READ. https://forums.qrz.com/index.php?threads/is-man-made-noise-really-vertical.629348/ HERE ARE A COUPLE EXCERPTS. One suggestion is that the difference lies in the antenna itself. What if both noise sources, horizontal and vertically polarised were the same, but the antenna heard them differently, how would that look? For starters, a horizontal dipole has a higher sensitivity at a higher angle than a vertical antenna does. So anything arriving at a low angle is picked up by the vertical, but not by the horizontal dipole. The noise that we're talking about is local, we'll get to why in just a moment. Being local, it gets to the antenna via ground wave propagation rather than via the ionosphere. I claimed that the man-made noise we're discussing is local. It's not all local, but if it's remote, it's coming via the ionosphere and we know that it arrives at whatever angle it pleases, so there is little or no difference between a vertical and a horizontal dipole from a noise perspective for signals arriving via the ionosphere. One more thing. The isolation between vertical and horizontal polarisation can be as much as 40 dB, so a horizontal dipole won't hear vertically polarised signals well if at all and vice versa.
40m is a bag of mixed plagues here too... 2 automatic garage doors, a power sub-station, cars on the street, electric fences, a few solar panels inverters... hopeless, can't fight all that not to mention Christmas season hash. Probably new buildings gonna hinder the power station, one day (in 3 to 4 years?) and when there's no single house left, solar panels are all gone too... To AnateLabre aka regulatory agency / ham lobbyist On HF and considering my B-A station, I'm only allowed/able 7.000 to 7.040MHz A1A, that's exactly the MOST ruined part of Radio here! Come on, you can do worse, get back to work, a little effort and you've totally killed all R-A for me! Oliver
