I've been experimenting with different transmitters and I just happened to have a Raspberry Pi laying around. After fiddling around for a couple of hours I managed to get it to transmit an AM signal. However it seemed to be dividing the clock signals wrong, such that any audio file piped into it seemed to be 3X+ its normal speed. Just wondering if anyone has had better luck with the software. Here is a link to the software on Github:
https://github.com/F5OEO/rpitx