View Full Version : Question about cable modems?

27-03-2007, 03:17 PM
Hi all,

I just have a question regarding the cable modems. Are cable modems susceptible to overvoltages when subscribed through cable company? As i know that the ADSL routers are susceptible to overvoltages through the telephone line and so they do need protection in the router. Does anybody know if the cable modems are similar situation?

I have googled it but didnt have much luck. If possible can anyone also provide a link with that information.

Thanks heaps,

Murray P
27-03-2007, 04:26 PM
I would imagine the are Groovy, however I don't have any solid evidence.

I have mine plugged in to a UPS, though the the UPS doesn't have a coaxial cable connection (just network & RJ11/phone), so I'm probably wasting my time.

Where are you and what sort/brand of modem is it?

27-03-2007, 05:19 PM
I do not have a cable modem, but i was just trying to find out thats all. I have read through some cable modem websites but no luck with them. Thanks though.

27-03-2007, 07:07 PM
Any device that has a connection to two discrete networks has a higher susceptibility to "overvoltage" (Actually transient "spikes" of high voltage that might only be a few nanoseconds or milliseconds in length)

This includes PC dial-up modems, ADSL modems, Cable modems, Cordless phone base units etc.

With power line disturbances or nearby electrical storms, a significant potential difference can exist momentarily between the two networks. Even a UPS can fail to protect this as it still comes in the "other" network.

There comes a point where a high level of protection is more expensive the equipment replacement or that very close protection on the incoming signal could affect the speed.

27-03-2007, 07:48 PM
yes. you can get spike suppressors for coaxial cables. not sure if any of the cheap tv ones would work tho.