Hi Fenris, 20 / 25mts max cable run, Westflex are based near enough to collect from and very patient with a techno-dummy.
25m of Westflex 103 has a loss of 3.25dB, which is less than the supplied antenna's cable. How easily accessible is the place you intend to put your antenna? If it's really difficult to get to, then if you were to decide you need a preamp after trying just the Westflex then it would be a lot of extra effort.
I've just calculated the change in system noise figure for the difference between a 10m vs 25m run of Westflex using a 0.9dB NF 12 dB gain preamp. It's 0.2dB, which is tiny.
For the cable alone, you lose 3.25-1.3 dB, so 1.95dB. That's getting to the point where you would begin to notice it, but probably only for signals which are quite marginal.
It's hard to give you good advice on this, you might be perfectly happy with a long cable run and no pre-amp, and indeed you might find that spending the money on a preamp would not really improve your coverage very much. If your range is limited by obstructions on the horizon (mine is, as I live in a river valley), a preamp is less effective because without line of sight the path loss increases rapidly. 1.1GHz just won't pass through very much earth!
The best advice is to try and reduce the cable length as much as possible.
