hi mike,

How much output power are you planning on using ?

One thing to watch out for is if these mp3 files are of
copyrighted work, you may have to pay to broadcast
these files.

You could try using two antenna, each cut for the FM
frequency you want to use. Connect them with a long
section of good coax, you just built a passive repeater.

Locate one antenna outside the building and the other
inside and thay could work for some or all building.

alex

Mike wrote:

Well, sort of.
I want to broadcast an FM radio signal playing MP3 files in a variety of
buildings from single story homes to multistoried buildings.
Small dwellings are no problems but the larger ones present a problem. The
location of the broadcast unit may be mandated by factors beyond my control.
The power needed to reach the opposite corner might be to high.
Is there any way to use internal wiring as a short range antenna that would
be limited to the building for all practical purposes.

Another possible solution that I can't find an answer to would be to put the
signal on an unused TV channel if the building is wired for cable.

I've done a lot of Google searching but can't find anything specific.

Thanks.