Many thanks to SWLing Post contributor Dan Greenall, who writes:
Hi Thomas
The concept of transmitting images through SDR waterfalls is relatively new to me. Last weekend, while listening to pirate Radio 48 (via Mix Radio International) remotely on SDRs in Rochester, NY, and Cape Cod, MA, I snapped these photos of their 10 kHz-wide USB signal on 6935, along with some of the pictures and text that scrolled down beside it.
Less than 24 hours later, I came across another stream of graphics, this time on 6960 kHz. It displayed a web page address for Radio Free Spirit. These were followed by a brief stream of audio on USB of a man and woman having a conversation, which ended abruptly without any announcement. I searched out an email address for Radio Free Spirit and sent off an inquiry. Within 15 minutes, a response was received confirming it had been them, simply running a test and had not expected anyone to hear them or reply.
Photos taken of both stations are attached here along with some related audio clips.
Radio 48:
Radio Free Spirit:
I am wondering if others have had experiences with this type of reception and if any international broadcasters have ever dabbled in it.
73
Dan Greenall, Ontario, Canada