Is there a BT transmitter would cover about 5 acres? It would be connected to TV to play the music channels, radio, or to the Ipod.
Thinking of maybe mounting on the roof of the pole barn.

Bluetooth is a specific very low-power wireless protocol. Typical Bluetooth devices have a maximum range of MAYBE 30 feet. There are even lower-power connection protocols included in the Bluetooth spec that have even shorter ranges.

The newest Bluetooth version, Bluetooth 5, supports a higher-power, longer-range connection up to a few hundred feet, but there aren't many devices that use Bluetooth 5 yet and it still probably wouldn't cover 5 acres well.

A radio-based device could certainly be built that would work over a 5 acre lot, and I'm sure there are some out there.

You could also probably do something with streaming over WiFi. I bet a good outdoor access point mounted on top of a building would cover a 5 acre lot. Of course, at that point, you might as well just stream music on a smartphone over the WiFi.

For that matter, you could just download music to a smartphone and play it without any connection at all.

Its very nature limits it Op range. I wouldn’t use it but There are BT extenders, Cassia Hub is one that comes to mind. You can start your research there.

This message has been edited. Last edited by: CQB60,

BT is incapable of that.
Wrong protocol for the job.
For 5 acres look to 900mhz or similar.