"we have very limited venues for advertising local business, hence the need for a radio station"
That's not just Friday Harbor, any more 🙂
Most folks will probably come to the same conclusion when they look around their own home towns.
Put yourselves in a small business owner's shoes and look around your community for ways you might advertise affordably.
Most would say it's pretty tough to find the kind of options that used to exist ten years ago.
Then re-read these articles about quasi-commercial uses of Low Power Radio:
Press Coverage of Low Power Operations
High Potential of Low-Power Radio
I bought a little audio transformer at Radio Shack that was 8 Ohm / 1000 Ohm and center tapped at 500 Ohms
I used the 8 Ohm for the input from a weather radio receiver earphone jack and the 500 Ohm for the output to the TH XMTR.
I had to buy an isolation transformer to use a PC sound card with the TH XMTR, I bought that at WalMart on the Scoche rack (same place the little FM transmitters come from) intended for aotomotive use. Works great.