[rabbit73]

Is this the comparison you are suggesting (see bold):

OTA signals are constantly changing. If you want a real-time side-by-side comparison between two tuners, you can insert a splitter after the antenna system to feed the Roamio tuner and a TV, and feed a second TV connected directly to the splitter.

If something bad happens as shown on the TV connected to the Roamio tuner, you can see if it also happens to the TV connected directly to the splitter.

Yes

Is there any risk damaging a TV tuner sending that much signal to a single tuner? So you are taking about inserting a two out splitter after the output of my AC7 combiner (one output to the Roamio and one output to a 2nd televison)?

Not that I can tell, but there is no way I can guarantee that nothing bad will happen if you try it. If you dropped your TV while moving it, you would curse me. I believe in non-destructive testing, not testing to destruction.

I always learn something from every one of my antenna tests.

You are already sending that much signal to your Roamio in your present setup. What I'm suggesting would send half as much to it:

91XG > LNA 100 >                         Roamio > TV
                \                       /
                  AC7 > 2-way splitter >  
                /                       \ 
           C2V >                         2nd TV

What I'm looking for are some clues for further improvement.

You are now on your 5th thread for your reception problem. You have made a lot of progress, and have learned a lot, but have reached the point of diminishing returns as ADTech has implied. At the beginning, you got a large improvement with little effort; now a large effort is needed to get even a small improvement.

Only you can decide if the possible benefit of the test is worth the trouble and risk. I am curious about what is causing the errors, but not curious enough to force you to do something against your will.

If you do make the side-by-side comparison test, the results might be inconclusive.

If you want to quit at this point, and settle for the improvement you already have, that's fine with me.

There is another type of interference that might be causing you problems, which is from strong local signals from other services like paging transmitters, police, fire, and taxi.