[ADTech]

I don't see any error in TVFool's database for KTVU. Please note that San Bruno is only several miles south of Sutro resulting in a 10 degree spread of signals between Sutro and San Bruno as seen from Dublin. Az 150 most closely is in the direction of Mt Allison and Monument Peak which overlooks Milpitas.

You're working with severely diffracted signals at your location in Dublin. It appears you're about 1000' below a 1400' peak that is dead in your LOS to Sutro. Such locations often are far more varied than the somewhat simplified modelling offered by TVFool's modelling engine. Don't get me wrong, it's the best tool available to the public, but it does have limitations. Consequently it's estimates for diffracted signals may vary widely from actual conditions on the ground.

In situations such as yours, the first recommendation is to try a different mounting location. Sometimes, this alone will resolve problems, especially if you are encountering what I call "frequency-specific multi-path" in which an errant reflection affects either a single channel or a very narrow range of channels.

The next step, should relocation not be effective, would be to step up to a deep-fringe UHF antenna, either an 8-bay or a Yagi. Your antenna is intended to suburban or close-in work and the UHF section may be a bit insufficient for your particular conditions.