The CM-4228 is UHF only, and you should have several VHF stations in San Francisco. The ridge could make a difference, but I have to think something is wrong with the installation.
You should have had at least limited success with your old antenna. It's even possible that your old antenna might do a better job, depending on what it is. Do you know what model or kind of antenna you had before the CM-4228? Are you using a digital TV or a converter box?
Ok if you think it's an install problem then there's some hope.
I've looked at the the channel list, don't need anything in the VHF band.
The old antenna was feeding a Channel Master converter box for a while but with little success, only an occasional stuttering channel after the conversion. That was an old rusty large antenna on a 20 ft mast, originally specified by a ham radio neighbor who moved away long ago. That antenna had been up so long the guy wires rusted and it fell. I've been trying out the CM4228 with its CM amplifier on a balcony outside the attic, not as high as the antenna that fell but at least second story. I thought experimenting there would predict my results of putting it on a mast.
One improvement I tried was replace the Channel Master converter box and old tv with a modern Samsung flat screen tv. I think I concluded the CM converter box had a better amplifier in it than the new tv.
Is that Winegard antenna sufficiently better than the CM4228 that it's worth buying to try out, or should I just try more tinkering with the CM4228? Aside from decent reviews another reason I chose the CM4228 is it's flat, and easier to work with compared to a long antenna with many elements.
Putting a new 20 ft or more mast on the roof is another issue, I phoned around and nobody does this any more, only dish antennas, and those guys wouldn't touch my project. I may end up with a simple tripod mount I can do myself - if I can get any antenna to receive anything to show me its worthwhile. I used to work construction, no fear of heights but as I approach mid-70's I'm aware my sense of balance is no longer sufficient for a project on a second story roof, at least anything more difficult than a tripod mount. Putting guy wires at the edges of a steep roof is something I have done ... but that was sometime back when Reagan was governor here.
Any/all advice appreciated!