Join Date: Mar 2008
Location: Drayton Valley, Alberta
6.9 would be a recommended minimum. that doesn't mean it will start to cut out as soon as you get below that, it's just from past experience that i've learned if you have less than that you're probably going to have trouble in bad weather or the slightest rf interference in the area.
for cabling you generally don't want to go over 125 feet of cable unless you add an in line amplifier. for most systems now you want an amp that will pass a 22khz tone so that your receiver can select channels on f2. the best place to put the amp is somewhere in the cable run before you've lost a lot of signal, say halfway down the cable run, not at the receiver, not at the dish. the trouble with existing cable in the walls, is you don't know what's hidden behind the drywall, a splitter, a staple driven through it, a bad kink behind the wall plate, pinched between studs, or a 100 feet coiled up in the attic. if it's rg6 cable it may be fine but age is a factor as well, the foam dielectric inside and the insulation outside can deteriorate. the wire itself can get oxidized and make for poor connections. if in doubt run new cable, or get a noise generator and spectrum analyzer to inspect the old stuff.