I have used one in the past to dig out weak signals (this is called DXing)
However unless your (DXing) with a very good beam antenna (High DB gain) it's not worth the trade off as the preamp will only increase noise and intermod problems that comes with it !
Now if your thinking of buying it to make up for the 50ft coax I would not bother as the small amount of db loss would not be worth the S/N trade off
Nope you would be much better off buying a coax with less db loss or even better a antenna with more gain
73s
Glenn KB6HLM Las Vegas, NV