by KNP 2516 » Mon Jul 13, 2009 9:23 am
Sometimes performance cannot be listed as simple as how much do I need to spend.
There are limitations to UHF, no matter what the range.
You have to understand that UHF is line of sight.
Sight vs. sound
UHF is like a pin point of light. If you shine it in the air, it does not go down holes - valleys. If you shine it at the side of a hill, it does not go up one side and down the next. If you are standing on one side of a building it does not shine around the corner and to the other side.
VHF is like sound, if you yell, the sound goes up one hill and down the next. It goes through buildings and around corners.
What you had before was VHF and what you have now is UHF.
If you went to Chicago and stood on the shore of Lake Michigan, and looked out over the water - if someone built a 3,000 foot tall tower 40 miles from Chicago - you might still be able to see the red light at the top of the tower. That is line of sight.
Yes the horizon is only about 26 miles, but due to refraction of the light waves, the light bends over the horizon and lets you see the light at the top of the tower.
Radio waves are affected the same as light waves. Refraction, reflection and diffraction are the three main points to ponder.
So basically the first 40 miles, you have a line of sight transmission, great.
The next 15 miles you have the first reflection of the waves - hence 1 edge of the signal.
About 10 miles after that you have the second reflection of the signal - hence 2 edge of the signal.
About 10 miles after that - you have a third reflection - hence Tropo.
The first signal is the true signal, it is watchable and is very easy to receive with a good antenna, proper height and maybe even a small pre amplifier to overcome loss in the wire and splitters in the house.
The second signal is a reflection of the first signal, it is harder to receive, more prone to drop outs, pixelation, and static interference from local sources, motors, electric fences, automobile ignitions etc.
It can be improved by the use of a very good antenna and a pre amplifier. At that point, you have to remember that the best signal possible is going to be at the antenna and everything after that is going to be loss. Line loss, splitter loss, etc. At that point, the use of RG 6 Quad Shield is a must, along with a good amplifier - but at that point - you also have to remember that one local station can over power the amplifier and you could end up with a blue screen, even though you have a good signal on the roof for one station and so so signals for the rest. The second signal a antenna rotor is a must.
The third signal - the reception is going to depend on the weather and the time of day. The best pre amplifier is a must, along with the very best long range antenna. Even then reliable reception is iffy at best.
By the time you get to 65+ miles, about the only signal you are going to get is tropo. Sometimes on some days - if at all. You will get a signal. Any station that is less than 1000 KW in the upper ranges of UHF, or is close to another station in a near frequency - you are going to have problems receiving it. When the sun comes out early in the morning and the ground begins to heat up - you will get a signal from the inversion layer in the atmosphere. In the late evening when the ground begins to cool, and the sky is cold, you will get a second inversion layer reception for a couple of hours.
It is not a reliable signal to receive.
You also have to remember that Fog, rain, snow, flocks of migrating birds,trees, and leaves on trees, swarms of bugs, airplanes, buildings more than 4 stories high and anything else that can get between you and the signal is going to block the signal.
To get that signal, you have to look at what is in your first and second fresnel zones. If everything is good, which usually it is not, then you can make plans for a antenna.
My advice is to get the antenna as high as possible. 100 feet or more ( Height = Gain) and use a Winegard 8200U antenna and a Winegard 8275 pre amplifier. A good digital antenna rotor like the RCA model sold in the Lowes stores. Belden 1829 AC wire. Keep your antenna wire runs as short as possible - do not keep a couple of extra feet of wire looped in your basement - in case you need it. Keep splitters to a minimum - and no more than a two way splitter anywhere in the system. Splitters are not unilateral.
What that means is that if a splitter was unilateral - if I was to walk into a splitter, two identical me's would walk out the other side. We would both have eyes and ears and noses and arms and legs and torso's that were the same size.
Unfortunately all splitters has loss. A 2 way splitter has at least 3.7 db of loss, some have even more.
3 db of loss equals the loss of half the original signal.
When you go to a 3 way splitter you might have as much as 7 db of loss on any one port /More than twice the loss of the original signal.
Use crimp on connectors only and put the pre amp power injector as close to the television as possible.
Put the pre amp box as close to the antenna as possible.
Keep antenna away from all power lines and trees.
There is no one single antenna that does everything and there is no one real answer to your question.
The 8200U in my opinion is one of the best antenna's on the market for the reception of both UHF and VHF television signals for long range reception.