Does an P-Inverter RFI/EMI buzz block internet connection??? HELP!!!


New member
Jun 29, 2004
HI any one who can advise...

I have a small office and I installed a power inverter. So I notice that when the power go off and the inverter comes in, my dial-up connection is blocked and I can't connect again until next day, if there is power. If the inverter is on, the internet won't work. So I called Verizon and they told me that power inverters make a noise called EMI or RFI, and that damages or affects the ohone line. My phone line is fine, it's just internet what doesn't work.

I read that there are filters in the market, that can filter the noise... does any one know about it? any solution????


Jan 1, 2002
There are others far more knowledgable than me that will answer this question BUT, ... I have had an inverter for about 8 years & internet dial-up always used to work with the inverter. About 6 months ago when I had problems with the 'failing' line to my house, when the power went off (& the buzz of the inverter commenced) my internet connection would get 'bounced' & I would have to await the line to "clean" itself or the power to return!!

I got hold of a Belling power resistor which has line cleaning abilities (DON'T ask me how, why or wherefores PLEASE) by passing the internet/phone lines via this resistor. Problem now solved - a CLEAN line at all times!! Is your internet connection near your photocopy machine?? Or maybe near the fax machine?? Might be that you asre getting a "Dirty Line" because of electrical feedback from these.

Speak to MrMike at Santiago - I am SURE he will sort your problem out for you. He is a 'Good Guy' to boot!!! - Grahame.


Mar 2, 2003
Thanks Graham,

Most likely your modem is reacting to a lower quality than acceptable wave form coming from the inverter. Basically your wave form is too square. I don't know of any equipment that can fix this, I have heard a line conditioner may be able to do it, but most likely it will react badly to a square wave form, since they are designed to clean true sine waves for pro audio equipment and the like.

The cheapest way to get around this issue is to try a different modem, different brand, etc. Modems are cheap these days, so for 15 bucks you should be able to try several.

If that doesn't do it, the only way for you to get back on line will be to get a better inverter, like a Trace.

Jerry K

New member
Jan 1, 2002
Static on the line

The RFI stands for Radio Frequency interference which is eliminated by putting in an inline filter. EMI is another term for basically the same thing.
Some appliances or electronic devices like a TV emit a signal that can interfere with reception on a radio frequency..The filter is actually a capactior to block the interference.
One possible problem is your new invertor is putting out the voltage but not the required 60 cycles and it would take a real electrician to correct it.
Check your invertor for the # of cycles, some countries use 50 cycles instead of 60. See if Radio Shack ( SD & Santiago ) stock any type of RF filter.
When cars had points in the ignition, could could buy a filter to keep the ignition noise out of your radio. If was just a big capacitor.