37m cable from modem to BUC ??

Well, most providers have specifications pertinent to their own equipment. But under most circumstances, 37m should not be considered a long cable run. My own is in the neighborhood of 35m. I use Belden 1829BC RG6/U; 3GHz swept, flooded, solid copper center conductor, 6.4 ohms/1000'. Measured resistance on my installed 220' loop is 1.55 ohms. Not bad - when you consider the loop includes 12 compression connectors, 3 barrel connectors, and two trips through the ground block.

//greg//

Here is a table referring to a LinkStar modem with external power supply.

For an 8W BUC do make sure you use cable with low DC resistance.
Low DC resistance cables have larger diameter centre conductors and larger diameter outer conductors (for 75 ohm RF impedance) and the large diameter centre conductor may not be suitable for the F sockets at each end in which case you will have to buy special F connectors which have a centre ferrule/pin as a specific part, with crimp/solder for the cable centre conductor.  You may need a special axial crimp tool for the outer.  Get F plugs that match the cable.

Best regards, Eric.