Why is it during the day I will get a different strength than at night? What about windy weather or a front moving through or rain? Curious.
Different signal strenghts
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It's not so much the weather, but the ionosphere. It varies with weather conditions and inversions take place up there causing the TV signal reflections to vary in distance and strength. I'm not up on exactly how it happens, but I've seen signals from stations that are 65 miles away double in strength at times. From what I've observed, low VHF, high VHF and UHF are all affected differently. While signals on channels 7 to 12 might be extra strong, nothing will be happening to the UHF signals, or the reverse could be true where you get increases from the UHF stations, but the VHF stations remain at normal levels. At times all of the channels can be affected.
There's also the affect of the Troposphere, especially in the Central US and on the east coast where stations from 200 to 400 miles away come in like they're right near by. We don't see that much out here on the west coast, but you probably have seen distant stations coming in at times there in Georgia.
Maybe someone else can chime in with more details and information.
There's also the affect of the Troposphere, especially in the Central US and on the east coast where stations from 200 to 400 miles away come in like they're right near by. We don't see that much out here on the west coast, but you probably have seen distant stations coming in at times there in Georgia.
Maybe someone else can chime in with more details and information.
Might want to take a look at this site: http://www.dxinfocentre.com/tropo_eur.html
which 'covers Europe. And this one that is US based monitoring the HAM 2 meter band. http://aprs.mountainlake.k12.mn.us/ & http://www.dxmaps.com/spots/map.php?Lan=E&Frec=430&ML=M&Map=NA&DXC=N&HF=N&GL=N
which 'covers Europe. And this one that is US based monitoring the HAM 2 meter band. http://aprs.mountainlake.k12.mn.us/ & http://www.dxmaps.com/spots/map.php?Lan=E&Frec=430&ML=M&Map=NA&DXC=N&HF=N&GL=N
Tropospheric ducting can increase signal at night, the first link that Fat Air posted above has the maps for it.
my distant VHF (KEYC 12) when I lived in Minneapolis always showed better signal during the night than the day. It was 72 miles away
thunderstorms between you and the tv towers can cause issues too
thunderstorms between you and the tv towers can cause issues too
The sun is a tremendous generator of RF energy on all frequencies and thus it does generate some background noise.
That background noise from the sun is partially blocked at night by the mass of the earth, so weaker TV signals are often more easily received at night.
The wind can effect signal strength if it moves the antenna off axis to the station or moves the antenna into and out of a null point (spot where signal is weak).
Weather fronts can act as lenses for radio waves (sometimes reflective, sometimes refractive), and the effect can be positive or negative depending on your relative location to the lens effect.
All of these phenomena are most observed on weak signals, strong signals would usually push their way through regardless.
That background noise from the sun is partially blocked at night by the mass of the earth, so weaker TV signals are often more easily received at night.
The wind can effect signal strength if it moves the antenna off axis to the station or moves the antenna into and out of a null point (spot where signal is weak).
Weather fronts can act as lenses for radio waves (sometimes reflective, sometimes refractive), and the effect can be positive or negative depending on your relative location to the lens effect.
All of these phenomena are most observed on weak signals, strong signals would usually push their way through regardless.
