benj said:
While long cable runs should be avoided, cable runs of 100' feet from LNB to receiver are perfectly fine. Average signal loss over standard-grade SBCA-certified RG-6 is -5 to -6 db. Most IRDs can handle more than -25 db loss before you'll experience problems. That does not mean a cable run of 500' will be without problems; once you get to that length, you'll experience premature rain-fade, S/N ratio problems and voltage drop issues. Most customers never even come close to these kinds of cable runs. Each wall plate connection/splice has -1.5 db loss and each multiswitch has -3 to -6 db insertion loss. Add all those up figures up and you start to get an idea of how long the cable runs can be. DirecTV's recommendation is 150 ft from LNB to receiver. This figure is very conservative and rightly so. If they recommended a higher number, they would then have X more installs with cable runs averaging N + 50'-100' where N is the recommended cable run length. Keeping the number lower than necessary ensures a 'control' of sorts to keep a large majority of the systems from running with out-of-spec cable lengths.
I think what charper1 was trying to say that "unnecessary splices" are too be avoided. I would qualify that a little more by saying "unnecessary splices on the outside of the dwelling" should be avoided if it can as the most likely culprit will be corrosion, not signal loss.
if your dish has to be 'far' from the home proper, call D* and insist on a powered multiswitch, called a 4X8 when the tech comes out, as that will improve your 'at the face of the residence' power levels. here far would constitute over a hundred feet. the switch completely revitalizes the signals, plus it gives you upgradeability, as it has eight outputs inherent.
any comptetent installer with 48" and 72" flexbits can get you wire wherever you want it, though if i have to break out a flex i start talking money immediately. this is not due to the labor intensiveness, but to the liability. i haven't cut power lines or come through a wall or ceiling yet, but when statistics catch up with me and i do, i'll be paying for the repair, so i have to make money to offset risk. that said, i can take a masonry bit through your exterior wall, switch to the 72" bit and bring you a wire six foot in from the side of the residence anywhere in your basement (that would be a ceiling level jack, if you wanted it down at the normal height, a lot more time gets spent fishing the cable down from the top, and costs rise).
i tell any customer on a mover's connect that i can run them a line to any room from outside, and the exposure for them will be limited but they can bury the wire from the ground block to the egress point and there would be no additional charges. D*'s dish requires a line per receiver, so you'll end up with four lines going away from ground toward your TV rooms, though these lines can be made to disappear by painting them the color of your home.
hope some of this helps
senior tech, north florida