What you have there is made just for legacy downconverted sat. frequencies, not over-the-air TV signals. OTA UHF is now limited to channels 14-69, freq. range, approx. 471 to 801 MHz. The D903 won't do you any good for your intended application, nor for more modern DBS equipment that operates at ~2250MHz.
What do you receive now? Can your UHF antenna provide an adequate signal if connected to just 1 TV? If so, then you may not need an amp at all. If you split the signal with a conventional VHF/UHF "combiner/splitter" and the signal is OK then don't bother with any amp. If the signal that was OK directly connected to one TV gets too weak to lock when it's split to two TVs, then you'd probably be best with a distribution amp that would give you a modest gain at each output, enough to cover the min. 3dB splitting loss. If you don't have an adequate signal when directly connected to just 1 TV, then you might need a preamp mounted at the antenna, and there are quite a few choices. But in this last case, there are many other considerations, like signal quality in general at your location, what antenna you're using, cable type and run length, etc. What channels are you trying to receive? Have you ever received them?
Hope this helps. Give us some additional information about your situation and we can provide a more definitive answer...
