With coaxial the higher channels will lose more than the lower thus producing decibel "tilt" .
RG6 typically drops 7.4 db at 400 mhz. So if you have a 300' run you will lose 22.2 db total at that freq. Then add 4 to 6 db at each leg coming off the switch. There are also insertion loss's for the connectors but these are minimal unless not installed properly.
You can get into the negative db's at the tv (-6, -8 ) and still have a good picture but much more than that and your screwed, especially on the higher end.
I have minimal experience with sat's and lnb outputs so if I am overlooking something my apologies. In catv, a 300 foot run is too long. Using RG11 coax (from the lnb to the switch) instead of rg6 is the usual catv solution. An inline amp might help but if your down in the mud your amplifing mud.
Here are some links that might help.
http://www.timesmicrowave.com/cgi-bin/calculate.pl
http://www.rfcafe.com/references/electrical/coax_chart.htm
Re: how much is to much cable in a dtv system
Member #: 11639
Registered: 1996-2001
Posted:
260
Name:
Paul Schuster
Name:
Paul Schuster
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Datawire
Occupation:
sweeptech
Location:
gulf shores, al
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