[rabbit73]

First, you set up a separate high gain UHF antenna aimed at 211 degrees magnetic and a preamp to see if it is even possible to receive KTVU and KRON at your location. This separate system should be connected directly to a TV for the test.

Sometimes it helps to tilt the front of the antenna UP if your location is behind a hill.

At this time of year, there might still be some Tropospheric Propagation to help you. When the cold weather comes, there will be less tropo to help you.

Doing a report at 40 feet doesn't seem to help you because you are well below the peak of the mountain and very close to the mountain. If the signals were just grazing the crest of the terrain, it would make a bigger difference.

If you are able to receive KTVU and KRON, then it would be the time to consider combining. You will be combining two UHF antennas. If you use a splitter in reverse as a combiner, it doesn't always work. When the same signals from each antenna reach the combining point, they will interfere with each other if they are not in phase (arrive at the same instant). You just have to try it.

If you don't have all the channels after combining that you had when the antennas were separate, that method of combining doesn't work for you.

If combining using that method doesn't work, you can have a A/B switch to select which antenna you want to use. If your TV can't add a channel after scan, you will have to rescan after changing antennas.

To avoid that, you can connect the main antenna to the antenna input of the TV, and connect the SW antenna to a separate tuner with its output connected to the aux input of the TV.

A personal question:

If you already have stronger channels for Fox and MyN, why do you want KTVU and KRON?