“I think most modern tuners are far more tolerant of “too much signal” than they were a decade or 2 ago. You’d have to really bash the new ones to get them to the point of being overwhelmed. The AGC is pretty capable of squashing a hot signal.”
This is true for Television sets. I have inserted attenuators in my TV’s RF input coax line and seen very little change in the signal strength meter for the strongest signals. (That is what the automatic gain control circuitry is designed to do.)
But it is not true for a Tablo. The graph below comes from the Tablo webpage here:
Notice that they show the Tablo’s normal input range as -50dbm to -80dbm. (The -50 dbm is the strongest signal end.)
The ATSC guidelines for receivers give a range of -5 dbm to -83 dbm. That is a much larger range than the Tablo.
BlueCalcite is in a very unusual situation where he was getting still video (freeze ups) from time to time after the foliage fell off of the trees in his line-of-sight to the Cleveland transmitters. Tvfool was indicating reception problems by showing RED to Orange in Medina. The Green area was very small and behind a hill or ridge in his line of sight.
See my comment numbers 14 and 16 above.
Please do not advocate on his signal strength issues. His reception problem was real and it was unique. I have certainly never seen one like it. When he bypassed the 15db amplifier and installed attenuators, his Tablo operation improved.
But he does seem to have some additional problem. And I certainly have not been any help with that.
I doubt that the problem is cell phone towers since his Tablo performed well for at least 4 months until about November 2018 and then got progressively worse. (Just after all the leaves had fallen.) I doubt that his problem is erratic multipath too, and for the same reason. (those 4 months)
The most likely cause would seem to be that his Tablo has developed an intermittent problem which occurs randomly. I worked on audio, video, RF and digital electronic hardware for over 32 years and I hated intermittent problems.