In that particular area, you have to be very careful using an antenna
amplifier, especially if you are talking about a pre-amp mounted at the
antenna. Only a professional will know which amp will work in that
area. Some of the Sacramento signals are so strong on UHF that the
pre-amp can do more harm than good. Remember, doubling a weak signal
will help, but also doubling that very strong signal can put that
signal all over the dial. I had a pre-amp in a large directional
antenna in Sacramento and had to have it removed. I couldn't get ANY
distant channel as all the locals wiped them out. Using a weak amp
MIGHT help in this case. You CAN NOT improve the signal-to-noise ratio
at the antenna. What you hope to achieve is to keep as much of that
signal as possible. In other words, to reduce the lead losses. But
ALL pre-amps/amps introduce some noise. You can't get a better signal
that what you are getting at the antenna, no matter what you do.

You might check with dealers in your area. But I have an idea that if
you replaced your lead to just ONE coax cable from antenna to tv, you'd
see a major improvement in reception from San Francisco and/or Modesto.