You will have to make the decision on where you want it installed (at the base of the antenna or close to your scanner). If you go with the at the base install keep in mind about sealing it from the elements of rain, snow, high and low temps etc. Also if you use a power supply on it to power it (instead of batteries) you have to make sure the power cord is plugged in to a GFI receptacle.
A caution here - wideband preamps (without any way to adjust the gain) are liable to cause more issues with increased noise and overloading in certain situations (urban areas with lots of RF in the air are more prone to this...). Too certain scanners (GREs are more guilty of this...) can and do overload and desense when signals are too strong to be handled.
Your best bet here is a better antenna, and most importantly, low loss coax. This link illustrates this well. Keep in mind that a 3db loss is equivalent to roughly half the signal being lost.