Hi,
I am testing this equipment from LEPA in Majorca and things look very good.
Yes I suppose that more cable you use the more noise you will get.
I am using 20m of cable and things look prety good.
GP-1090 Antenna
1m low loss cable Ecoflex-10 with N connectors
Mast pre-amplifier AS-1090
20m low loss cable Ecoflex-10 with N connectors
AS-1090BT Bias-T for DC-Feed
1m Cable BNC/SMA
Got it from WIMO.com