Yes, the black box is the selector. The middle position combines the two antenna signals, the left button selects San Jose only, the right selects SF only. Most of the time I leave it in the middle position, which selects both antenna. Nothing more fancy than combining the two signals. There's nothing directional about the two-way splitters, so I just reversed one of them (the one in the middle) to combine two signals into one.
The box to the right with the little red light is a signal booster. After all that splitting and combining I figured the signal would need boosting, especially since it's then split into four cables running to separate areas of the house.
There is slightly more ghosting on some channels with the two antennae combined, but not much, and the digital picture comes in with no ghosting at all, of course. If the signal degrades in the winter with stormy weather, I'll just select one or the other antenna. I might also upgrade one or both antenna to better models with less corrosion on the elements, but for now they're just fine. Plus, digital signal are all UHF (as I understand) so a big antenna with the big VHF rods probably won't be necessary any more (and those are the ones that are falling off one antenna - I blame fat birds!).
All the cables are the best I could get - RG-6 as I recall - and are run under the house in the crawl space and then up into wall outlets or simple holes in edge of floor. It took a while to design and install all this, but I wasn't working at the time so it gave me something to do... lol...
The telephone wire connection block to the right is what's called a "66 block". It's ok for telephone signals, but not considered good enough for ethernet. I forget the name of the block that is best for that, but it has much smaller, hidden blades to connect the wires, for less signal loss/distortion. At some point I will have ethernet going to all rooms, but don't really have the need at present. And for that I'll probably use a 100baseT hub with eight ports (ethernet to the workshop would be nice).
I used to work in the IT/computer business for about 15 years. Working as a machinist now. Pretty tired of computers; have had a new motherboard/processor plus hard drives to upgrade my main computer system here for about three years now... just can't get excited about it like I used to (plus I know all the complications that can ensue to make a 2 hour job into a 2 week job!).