Electroline EDA 2400 4-port RF/CATV Distribution Amplifier

This amp does the job. Forget about the $30 distribution amps - they often make things worse.
Dropped this amp into the line and all my marginal stations are now rock-solid and I can drive 3 other devices too! I'm very happy to see that the unit also has some surge protection as well.

I'm using this to distribute four modulated channels, 100, 103, 106, and 109, and standard cable TV that goes up to channel 82; I filter the cable TV signal before it enters the combiner with a low-pass filter at 600MHz, the LPF-600. The signal is enough better than a simple splitter to be worth the price. There is no sign of either interference or attenuation, from channel 2 to channel 109 (that's the highest channel I use). I use only three of the four outputs; one goes to my rumpus room TV, one to my home theater, and the other to an 8-output amplified splitter to the remainder of the house. The fourth output is terminated with a standard cable terminator, and I recommend this for all such devices to avoid interference. The wall wart can be integrated into one of the outputs, and that can make power for this unit extremely easy to configure; I don't use that feature so I can't comment on it.

Forget about those other amplifier/splitters. They never work well, usually mess up digital HD cable and almost always mess up cable internet. This thing costs just a little more but actually works. I've used one of their products at my home for over 10 years with no issues, and just bought this one for my daughters house.