Coaxial Comments
Points to remember when it comes to coax

1 - Keep cable run as short as is practical.
2- Where possible avoid long horizontal runs.
3 - Higher the frequency band, the greater the loss.

Table below shows the signal loss to be expected over four lengths.
Losses shown in dB

Length                 5  Metres              10  Metres              15  Metres              20  Metres
Frequency
Coax Type		 128MHz 1090MHz 128MHz 1090MHz 128MHz 1090MHz 128MHz 1090MHz
RG58U 0.9 4.32 1.8 8.64 2.7 12.96 3.6 17.28
URM43 0.81 3.89 1.62 7.78 2.43 11.67 3.24 15.56
W103 0.2 0.74 0.4 1.48 0.6 2.22 0.8 2.96