Reply to thread

Message: [QUOTE="Mr. Know it all, post: 19405, member: 3410"]Can I say something - without sounding to crass?Almost none of your suggestions for a outdoor antenna are a good choice.Most all of those antenna's has some sort of limitation which keeps them from being good choices.Without going too deeply into this subject, the first point to ponder is that UHF television signals are line of sight.  That means that unless you can see the tower or unless some sort of refraction, diffraction or reflection momentarily sends the signal your way.  There is no way that you are going to receive it much past 65 miles.Two way that I explain line of sight is if you put up a transmitter tower 1000 feet above average terrain and you put up a receive tower and antenna 1000 feet above average terrain, you would get a good signal.The other way I can explain line of sight is if you put a transmitter 1000 meters tall ( 3280 feet tall) out in lake Erie and you stood on the shore 46 km away ( 28 miles ), you could still see the light on top of the tower.In telecommunication, radio horizon is the locus of points at which direct rays from an antenna are tangential to the surface of the Earth. If the Earth were a perfect sphere and there were no atmospheric anomalies, the radio horizon would be a circle. The radio horizon of the transmitting and receiving antennas can be added together to increase the effective communication range.Antenna heights above 1 million feet (1966 miles, or 3157 kilometres) will cover the entire hemisphere and not increase the radio horizon.VHF and UHF radio signals will bend slightly toward the Earth's surface. This bending effectively increases the radio horizon and therefore slightly increases the formula constant. Line-of-sight propagation refers to electro-magnetic radiation including light emissions traveling in a straight line. The rays or waves are diffracted, refracted, reflected, or absorbed by atmosphere and obstructions with material and generally cannot travel over the horizon or behind obstacles.Radio signals, like all electromagnetic radiation including light emissions, travel in straight lines. At low frequencies (below approximately 2 MHz or so) these signals travel as ground waves, which follow the Earth's curvature due to diffraction with the layers of atmosphere. This enables AM radio signals in low-noise environments to be received well after the transmitting antenna has dropped below the horizon. Additionally, frequencies between approximately 1 and 30 MHz, can be reflected by the F1/F2 Layer, thus giving radio transmissions in this range a potentially global reach along multiply deflected straight lines. The effects of multiple diffraction or reflection lead to macroscopically "quasi-curved paths".However, at higher frequencies and in lower levels of the atmosphere, neither of these effects apply. Thus any obstruction between the transmitting antenna and the receiving antenna will block the signal, just like the light that the eye may sense. Therefore, as the ability to visual sight a transmitting antenna (with regards to the limitations of the eye's resolution) roughly corresponds with the ability to receive a signal from it, the propagation characteristic of high-frequency radio is called "line-of-sight". The farthest possible point of propagation is referred to as the "radio horizon".In practice, the propagation characteristics of these radio waves vary substantially depending on the exact frequency and the strength of the transmitted signal (a function of both the transmitter and the antenna characteristics)[/QUOTE]

Name

Verification