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Re:Return path Problem w/ Modems



>I install a lot of cable modems. Have installed several kinds but the ones I'm havinf trouble with is the GI Surfboards. The cable modem is external and connects to an ethernet card.etc,etc,etc,
>the problem is that when it is hooked to a four way splitter or eight way the modem becomes unstable or works intermittingly. I use primarily Regal Gold 120db EMI or Tru Spec 120dB EMI. The modem would work fine thru a 2way or three way but 4's and 8's would kill it. The RF being sent back was 19MHz and it measured 45db before the 4 ways and 45 dB out of the four way input. This was very strange and have no explanation for it.Has anyone come across this before or know why this happens. It is easily gone around to get it going again but the WHY is peckin at me. help if ya can. Thanks
> (-REDACTED-)

I do not think it's a RFI problem. I think it is a problem of too much attenuation on the reverse path AND
a return loss problem when the 4 and 8 port splitters are connected. 45 dB out of the modem is plenty
hot, however after a 4 and 8 way split you maybe at below threshold to hit the reverse laser with correct
input. Your possible "fix" is a seperate drop to the modem or a drop amplifier with an active reverse. Thats
my take from the Teleprompter Cable TV class of '69.
This is CABL.com posting #28185. Tiny Link: cabl.co/mhuL
Posted in reply to: Return path Problem w/ Modems by PoleMonkey
There is 1 reply to this message
Re:Return path Problem w/ Modems VODSQUAD 12/11/2000 8:23:00 AM