This is posted under "Transmitters" because I consider an online radio server to be a true form of Part 15 transmitter, look at all the Part 15 Notices on the routers, motherboards, soundcards, and all, and I'm talking now about my radio servers.
It is even possible to have a backup transmitter (server) which came in handy when I installed the new version of Icecast Server, V 2.5 beta, requiring a shut-down of V 2.4.1.
To avoid listener down-time I ran a Shoutcast Server matching the Icecast specs, 64kbps, 22.05kHz, stereo.
This was lucky because the changeover took two days because of my slow success in getting the new Icecast software to start. Once it did start I ceremoniously ran both servers for a day before shutting down the Shoutcast Backup Sever.
Online streaming is antenna free!!
Yes I too have been saying this for years on the Shoutcast and other Internet Radio forums. The Software with the Encoder is the Transmitter. The Server be it Shoutcast or Icecast is the Relay which is why if you plan to have over 6 listeners at once its good to rent a server from one of the stream hosts. MyRadioStream is good because there is a FREE option and a Cheap paid option which allows one to listen on their mobile devices. Listen2myradio's FREE service will work on some androids right from the browser. Their paid version would allow you to be listed in the Shoutcast directory and be listed on directories like iTunes and TuneIn radio. Listen2myradio's price for premium is far higher than MyRadioStream. For $5.99/Month you really can't go wrong. Another nice service is fastcast4u.com which use to have the site freeshoutcast.com which is no longer free. MakeAVoice has both Shoutcast and Icecast servers. They even have Teamspeak servers which you can pay a monthly fee for. You can sort of skate by copyright (But be careful) by using UK servers like MyRadioStream as well as french servers like fastcast4u (Don't pick a USA server when you sign up. The downside is a little more buffering issues but I didn't seem to have those. I pay for licensed streaming so I can be listed in USA directories as most of those check to see if you have a royalty license. UK is fine for just getting on the Shoutcast directory and streaming under the radar. Hope this helps