Quote:
Originally Posted by jb66
When you have a long cable run RG11 is more effective than an HDU as the high frequency signals will be very low.
HDUs are mostly used in sid architecture where there are a set of taps every 20m. If your close to the amp there will be a 26db attenuated tap to lower the downstream, unfortunatly the upstream will also be attenuated by 26db so will be high. Its common for the upstream to be 47db from the pit in those situations. Add a 3 way splitter and a few connectors and the upstream rises above 55db.
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Just to expand on JB's explanation. If you are close to the amp, the upstream power required to be drawn from your modem will be lower than if you are further away. That's why the 0 dBmv/40 dBmv downstream/upstream sweet point rule of thumb is used. I'm close-ish to the amp and in the days before I had 4 taps at the hope, my modem only needed 29 dBmv to get back to the first active node (optical). Another rule of thumb is that each active node needs to see at least 15 dBmv input power - there are settings to control this and the rule is not fixed because of infrastructure differences from area to area.
Now mine is c. 40 dBmv. But in SID areas, it's as JB explains because of the attenuation at each pit.
But you can do the maths once you've worked out the upstream attenuation to the amp, plus the tap point attenuation etc. So JB is essentially correct.
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