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When switching from a directional/multidirectional antenna to an omnidirectional antenna, you sacrifice signal strength for the ability to receive signal in all directions.
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First let me say that the terms "multidirectional" and "omnidirectional" are creations of marketing departments that raise the hopes of a buyer and make him think that their antenna will be able to receive signals from many directions. It also makes it more difficult to help people that have been misled.
There are really only two: directional and bi-directional.
For best results, the antenna should be aimed directly at the transmitter for maximum gain and to reject multipath reflections. It will be possible to receive other signals at a slightly different azimuth within the beamwidth of the antenna at reduced gain.
What I said was to try the 4-bay antenna with the reflector first at 260 to see what you can get. Then rotate the antenna to 115 and see what you can get. At that point you might be able to pick just one direction that will make you happy without needing to remove the reflector. If you aren't happy, then it is time to remove the reflector to make the antenna bi-directional for more tests. I picked 260 because I thought it gave the best selection of the major networks.
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Just want to make sure I understand this correctly. A 4-bay antenna with reflector not removed is directional, but may still receive channels in both major directions shown on my map because the antenna pattern has lobes that allow it to receive signal 180 degrees from the aimed direction, just at a lower strength (see image below). Thus, if it worked, I would not need to sacrifice gain in the aimed direction. If, however, it doesn't work, I can try removing the reflector and sacrifice the gain to allow me to get a more symmetric reception pattern. Is all that more or less correct?
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That is more or less correct, but when the reflector is in place the antenna should be aimed at the weak signals direction so that the rear faces the strong signals direction. If you have strong and weak signals in both directions, you have a problem which requires one of these solutions:
1. Two antennas with an A/B switch to select which antenna you want to use
2. An antenna rotator to aim in different directions; an option with many disadvantages
3. Just be happy with what you can get in one direction
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I have one more question. Reading about the antenna you have suggested, I don't see any mention of a pre-amp/amplification. In my case, I do plan
to split the signal in 2 and run it a significant distance (50-100 feet). My first question is if I will need active signal splitting or not. Second, am I OK trying the setup without a pre-amp/amplification or is there a pretty good chance I will need it no matter what. If I will need it, what would be the best way to determine how much amplification I need and the best option for my particular setup.
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Your tvfool report shows very strong signals, but that is with an antenna outside and in the clear without any trees or other buildings in the way. Because there are so many unknown factors involved, there is no way I can predict your results. As rickbb said, you just have to try it.
I suggest you try the antenna with just one TV that hopefully has a signal strength indicator to help you. If that is OK then add a passive splitter for more than one TV. If the signals are too weak for more than one TV, substitute a distribution amp (active splitter) like the Channel Master 3412 or 3414 for the passive splitter. In rare cases when the attic loss is severe, a preamp at the antenna is needed.
WBTV has a Noise Margin of 67.7 dB. If you add the antenna gain of about 12 dB, that brings you up to 79.7 dB which is Overload territory.
Interpreting Noise Margin in the TV Fool Report
http://www.aa6g.org/DTV/Reception/tvfool_nm.html