Hello there, We just moved to new house and there is an AM radio station across the street that comes in loud and clear on my telephones and my computer sound system. I think it is also slowing down my modem connection also. Do you have any ideas on solving this frustrating problem.
BOB in Fairbanks

Hi. Your situation could be complicated but maybe not. Radio Interference may be entering your phone system and your computer (modem) via a number of paths.

Any length of wire connected to a piece of equipment can be a potential antenna for interference pickup. The most common sources of interference pickup are the phone line and the ac power line.

You may be lucky enough to solve the computer problem just by plugging in a filter between the line and the modem (at the modem).

Any other phone equipment connected to your phone system could be contributing to the problem so if you do try a filter you should disconnect all other equipment (fax machines, answering machines, cordless phones etc. Then try the filter.

If the interference is still there, you probably need to filter the ac line cord at the computer (this can be done by purchasing a $12.00 torroid (model FT240-77(J) from Amidon Associates in Santa Ana, CA (phone 714 850-4660) and winding as many turns of the ac cord as you can onto the torroid. The lead from this "filter" to the computer should be very short and a small extension cord can be used to reach the ac outlet. This and the telephone filter should solve the modem problem. Then you plug in the rest of the equipment one at a time checking your modem performance after each one.

If plugging in a piece of equipment brings the interference back then that piece of equipment probably needs the ac line cord treatment.

However, it is possible that a telephone filter may be all you need.

I hope this is of some help.
Sincerely,
John Browne


Click on the picture for RFI filter construction details.



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