Possibilities include:
tuner chip degrading; audio amplifier failing; other discrete component failure; AM is more sensitive to local radio interference than FM; microwave oven nearby; another radio, tv or computer nearby; surveillance bugs in area; wireless alarm systems; feedback from piggy-back radio using household power lines (which serve as the antenna system); proximity to high voltage power lines or radio/tv towers; or a local amateur radio transmitter in area.
Terrestrial noise is noise that originates on the earth. Extra terrestrial noise comes from space.
If you mean FM/AM radio: Radio reception is based off the bouncing of radio waves off of the upper atmospohere and ionosphere. But in the daylight, the sun causes molecular turbulence in those layers like photodissociation and infrared absorption. Imagine trying to look in a liquid mirror that has a lot of turbulence vs one that is rather stagnant. Sunlight makes the "mirror" of the upper atmosphere and ionosphere turbulent while in comparison the night sky is a more stagnant "mirror" Particularly, radio stations switch to low power mode some point after dark because of the substantial increase in transmission-reception ability. ---- If you mean radio astronomy: Your question is better stated, "why does the signal-to-noise ratio improve after sunset" where "improve" means "increase". Though it is not as dramatic as the visible or infrared emissions, the sun is a strong radio source. As a result, if we are looking for radio signals that are not the sun, then the sun is considered to be part of the background noise. Then after sunset, this noise source is propagating through the earth and not directly into the radio telescopes. As a result, the amplitude or level of noise has decreased and the signal has remained mostly the same and thus the signal-to-noise has increased by dividing by a smaller noise. signal-to-noise is literally "signal divided by noise".
The spiral shape lessens wind noise created by typical cylindrical shaped antennas masts. It is there for passenger compartment noise reduction only, and has nothing to do with the noise or clarity of the radio signal it receives.
The bearings in your front wheel. I've just changed mine as it sounded like I'd run over a dog
humming noise is a bad ground to the radio. you may have a loose connection. connect a ground wire to frame of truck.
Fruit bats.
why does my starter make a loud screeching noise when i start it?
You probably have a bad bearing.
Compressor locked up.
radio lol
The screeching noise is most likely the blower motor. Either the motor itself is bad or the fan blades are striking the housing. Run the heat without defrost and see if the noise is the same. Also check at different fan speeds to see if the noise changes.
a screeching noise
The cause of a loud screeching noise when a person turns the wheels a little, could be due to the lack of power steering fluid. It could also be due to worn belts.
POTATOES and YOUR MOM
A pig grunts or squeals
Eagles make a screeching noise
good chance the fan belt is slipping when driving may need tightning up this wouold cause a screeching noise.