What Causes Loss of Signal?

[Jellyby]

What causes a loss of hdtv signal? I found a location on our roof where our HD7696P antenna gets a very strong signal - Most of the time. For some reason on some days we can lose as many as two thirds of our stations. It might be for a few hours or a couple days. There isn't any discernible pattern weather wise. I have noticed that on some of these days we also have bad radio reception.

Because the signal is so strong (when it works) I haven't installed a preamp.

[winegard]

Good morning Jellyby -


First, I would suggest that you check your connections at the antenna and all the way through-out your system. Take the connections apart and look for corrosion, etc. and make sure they are tight. Movement in the connections can affect the signal strength going to the tuner which will affect picture quality.

Also, take a good luck at the direction the antenna is pointing and what obstacles it may have between it and the signal. Are there possible blowing tree limbs and leaves? Any other obstacles that could be moving in/out of obstruction? Is your antenna mounted near power lines? What other factors come into play where your antenna is mounted?

Finally, there are some atmospheric issues that can sometimes affect signal, but typically this is not the case.

[jacksonp]

Participating in the discussion given in the above post I wish to put light upon few points responsible for the loss of signals....they are as follows.
1. Loss due to free space - energy of the signal reduces depending upon the larger area that it need to travel .
2. Diffraction - diffraction is observed when the objects appear in the path of a traveling signal .
3. Atmosphere - the different layers of the atmosphere plays an important role in transportation of signal with different frequency.
4. Multipath - the path through which the signal travels also participate in the loss of signal.
5. Buildings and Vegetation - Even the buildings and vegetation plays a role in signal loss(by the means of reflection and absorption).