Simple answer to a complex question.
Since most television signals are horizontally polarized, when you tilt the antenna, it is not to receive the true signal - with LOS would provide. But to try to receive a signal which is refracted over the horizon and two edge.
If you stop and think about it, it will only work for a UHF signal and not for a VHF signal. The theory for the UHF Yagi antenna is that each director receives the signal, which is then reflected back to the next director which also receives the signal, but also add's that portion of the signal which it receives and the total of all the directors in the array is the total amount of gain over dipole.
That is the reason why the XG 91 Antenna's Direct aerial works so well.
The reflector behind the array and behind the dipole is what reflects the sum of all the parts of the signal back down against the dipole.
At the same time, when you point the rabbit ear antenna up in the air, you are skewing the signals - which when everything was VHF and analog, might have actually improved the signal. But with UHF and digital, the length of the aerials is very critical so as to be the same length - either full wave or 5/8 or half wave so that you can receive the signal. That type of antenna needs to be horizontally opposed 180* from each other.
Several examples for my area is channel 13 - which is 28 7/8ths inches long for a 1/2 wave antenna. On the other end of the spectrum, channel 51 - only requires a antenna 17 inches long for a full wave.
By using a frequency chart, a tape rule and a frequency conversion calculator, I can adjust the length of my rabbit ears antenna to tune in most any frequency above channel 13 and get the best possible signal.
Just as a example - channel 3 has a wavelength of about 46 1/8 inches for a quarter wave antenna. Could you imagine someone having a rabbit ears antenna inside of their house that was 184 inches long on each side.
They would have to live in a room the size of a basketball court just to be able to properly aim the antenna.
With a dipole antenna, aim is more critical as is placement. But if you keep the length of the wire going from the balun to the television as short as possible, you can really get some good signals out of it. Even a home built antenna with nothing more then two properly cut pieces of wire.
Since most television signals are horizontally polarized, when you tilt the antenna, it is not to receive the true signal - with LOS would provide. But to try to receive a signal which is refracted over the horizon and two edge.
If you stop and think about it, it will only work for a UHF signal and not for a VHF signal. The theory for the UHF Yagi antenna is that each director receives the signal, which is then reflected back to the next director which also receives the signal, but also add's that portion of the signal which it receives and the total of all the directors in the array is the total amount of gain over dipole.
That is the reason why the XG 91 Antenna's Direct aerial works so well.
The reflector behind the array and behind the dipole is what reflects the sum of all the parts of the signal back down against the dipole.
At the same time, when you point the rabbit ear antenna up in the air, you are skewing the signals - which when everything was VHF and analog, might have actually improved the signal. But with UHF and digital, the length of the aerials is very critical so as to be the same length - either full wave or 5/8 or half wave so that you can receive the signal. That type of antenna needs to be horizontally opposed 180* from each other.
Several examples for my area is channel 13 - which is 28 7/8ths inches long for a 1/2 wave antenna. On the other end of the spectrum, channel 51 - only requires a antenna 17 inches long for a full wave.
By using a frequency chart, a tape rule and a frequency conversion calculator, I can adjust the length of my rabbit ears antenna to tune in most any frequency above channel 13 and get the best possible signal.
Just as a example - channel 3 has a wavelength of about 46 1/8 inches for a quarter wave antenna. Could you imagine someone having a rabbit ears antenna inside of their house that was 184 inches long on each side.
They would have to live in a room the size of a basketball court just to be able to properly aim the antenna.
With a dipole antenna, aim is more critical as is placement. But if you keep the length of the wire going from the balun to the television as short as possible, you can really get some good signals out of it. Even a home built antenna with nothing more then two properly cut pieces of wire.
