I thought some might find it interesting to see what the extremely low frequency digital modulation looks like that rides on top of the BBC-R4 198 kHz carrier. This data is used all over GB to set clocks and I think even regulate some utilities etc.Also what is neat is if you look real close, just lower in freq than the digital data, right at 197.95 kHz you can see a trace in the waterfall of what I believe is some 50 Hz hum on their transmitted signal. It is on both sides of the carrier but there was some selective fading going on and the LSB was coming in better. I have some still JPG's of the hum that I can post if anyone is interested. They were taken a year ago using different software. This video was captured the other night during a period of poor signal strength. Not strong enough to get good audio but good enough to see the digital data. 73 Gedas W8BYA
www.youtube.com/watch?v=Tvr3Wo_TnF0