Can AM/FM broadcast bands be retransmitted inside a building?
Can AM/FM broadcast bands be retransmitted inside a building?
(OP)
Are there any repeaters or other methods of retransmitting the US broadcast bands (FM 87.8 to 108.0 MHz, AM 520 kHz–1610 kHz) inside a building? We are testing AM/FM radios, but our building is built of materials that block out all but a few really strong stations.
There is an antenna on the roof with 75-ohm coax coming down into the lab, but some units do not have any way of connecting an external antenna.
Any suggestions?
There is an antenna on the roof with 75-ohm coax coming down into the lab, but some units do not have any way of connecting an external antenna.
Any suggestions?
RE: Can AM/FM broadcast bands be retransmitted inside a building?
The more common approach of providing an external FM antenna system is simple using normal CATV components like amplifiers and splitters. AM you would have to home brew.
If an FM radio lacks an external connector, then you can just couple into the (plastic case?) radio with a length of wire. It is simple to try, so go for it.
RE: Can AM/FM broadcast bands be retransmitted inside a building?
RE: Can AM/FM broadcast bands be retransmitted inside a building?
For AM, you might try a loop to couple into the internal ferrite rod. Many years ago there was a craze for AM band DXing and various products touted the ability to pick-up signals even on the "Alaskan North Slope". Some of these silly plastic case loops provided antenna inputs.
Google AM DXing and you see all sorts of ideas.
It's not likely that you'll have both AM and FM bands on one coaxial cable. You'll probably end up with RG-59 coaxial cable carrying the FM band. And another RG-58 coaxial cable carrying the AM band. It is technically possible to combine them into one cable, but just not very likely to be off-the-shelf.
RE: Can AM/FM broadcast bands be retransmitted inside a building?
called the "Twin Coil Ferrite AM Antenna".
It has a big ferrite that is mounted outside, via coax, and
a small ferrite that is placed near the receiver.