>I installed a new computer for a local doctor's office. Now the
>neighbor's CB signal comes through loud and clear on the computer
>speakers. When they turn off the computer speakers, the signal
>interferes with the phone line. Turning the speaker volume down,
>or muting the volume on the desktop have no effect. According to
>the FCC this guy is within legal limits, and he doesn't seem to
>care that a whole doctor's office can hear his conversations.
>        The best suggestion I could come up with, was to plug headphones
>into the speakers. That would keep the signal from interfering
>with the phone line, and patients would not be able to hear, but,
>there must be a better way..

Your speaker and the neighbor's CB appear to be on the same frequency. The
way I understand it, a speaker vibrates in order to work, and it's doing it
at the same frequency that Mr. CB is sending his signal with. (This may be
an oversimplified explantion, I realize, in case there is anyone out there
with true expertise in this area.) I asked an engineer whom happen to be
married to, and got an explanation involving harmonics that I am not
educated enough to elaborate on.

Here is the suggested fix: try insulating the speaker with some kind of
material such as thin foam, putting a layer in front of the speaker, if it
will fit. I'd use something like weather stripping. My low-end speakers can
be opened with four screws. Put the insulating material in front of the
round part that vibates to make the sound; sorry, I don't know the
technical term for it. I realize this may dampen the sound slightly too,
but we are only talking about a small amount of insulating. The idea is
like sound-proofing, I believe; you will change the frequency of the
speaker slightly, hopefully enough to keep it out of the range of the
CB'er. If this does not help, you might also try wrapping the speaker wire
with an insulating material, which should be available at an electronics
store.

Do let us know of your results to this interesting problem!

regards
Susan Sutherland
S. Sutherland Consulting

                                  -----
       **Need help with PCBUILD mailing list? Send an Email to:**
        Bob Wright<[log in to unmask]> or Drew Dunn<[log in to unmask]>