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carpy · 21-06-2007, 01:54

You can't rely on him saying the signal is "strong" on his "reader" in the loft. Strong doesn't mean anything. There's a lot more involved than the strength.

What's the actual field strength on each multiplex?
What about the C/N ratio (carrier / noise ratio)?
What's the CBER (bit error rate before correction)?
What's the VBER (bit error rate after correction)?
What's the gain of the amplifier?
What's the stated maximum output of the amplifier?
What's the actual maximum output of the amplifier?
How much are the cable runs (to TVs) attenuating the signal?

To do it properly you need to know all the above, and that's just for the Freeview. If he's saying the signal is "strong" in the loft (after the amplifier), but then weak at both the TV points, then there's something majorly wrong which he should pick up on.

Sometimes the cable which feeds the TV point might have a nail through it, or it might have been cut and plastered over by the builders etc, but not both cables......

Worst case scenario even if you have the worst possible (poorest quality) cables run to the TV points, you won't lose enough to turn a strong signal into a weak one.

21-06-2007, 01:54	#41
carpy Inactive Join Date: Jun 2007 Posts: 20	Re: [Merged]Freeview aerial installation You can't rely on him saying the signal is "strong" on his "reader" in the loft. Strong doesn't mean anything. There's a lot more involved than the strength. What's the actual field strength on each multiplex? What about the C/N ratio (carrier / noise ratio)? What's the CBER (bit error rate before correction)? What's the VBER (bit error rate after correction)? What's the gain of the amplifier? What's the stated maximum output of the amplifier? What's the actual maximum output of the amplifier? How much are the cable runs (to TVs) attenuating the signal? To do it properly you need to know all the above, and that's just for the Freeview. If he's saying the signal is "strong" in the loft (after the amplifier), but then weak at both the TV points, then there's something majorly wrong which he should pick up on. Sometimes the cable which feeds the TV point might have a nail through it, or it might have been cut and plastered over by the builders etc, but not both cables...... Worst case scenario even if you have the worst possible (poorest quality) cables run to the TV points, you won't lose enough to turn a strong signal into a weak one.