(This is more amplitude than frequency related, but thought it might be interesting to the group. If not, sorry for the intrusion.) I used three software defined radios to record just under 1 TB of data during the eclipse period from my cottage at Beaver Island, Michigan, over 8 hours from 1400 to 2200 UTC. Frequencies recorded included the entire AM broadcast band and four ham radio bands, one of which also covers WWV at 10 MHz. (Obligatory time-nuts/FMT-nuts: the receivers were either locked to an FTS4100 cesium standard, or had reference markers derived from it.) It's taken a few days just to aggregate and back up the data. Last night I was able to do the first actual processing. This initial result is a "spectrum movie" showing the AM broadcast band from 0.500 to 2.00 MHz over the 8 hour test period, recorded by a Red Pitaya SDR at 2.5 megasamples/second. It will take more work to separate noise/spurs from real signals but it does look like carriers came up out of the noise during/after the eclipse period. The movie was created with a Gnuradio script reading the recorded data and displaying an FFT plot, which was captured with a screenshot tool every five seconds. I then turned the images into an .mp4 movie at 30 frames per second, so the 8 hour period runs by in a bit over 3 minutes. I used a deep FFT (8192 points) with long averaging to get rid of as much of the crud as possible. Blog post with some details here: http://blog.febo.com/wp/?p=202 Get directly to the movie on YouTube here: https://youtu.be/bqRhfCiD8Pw There's lot more analysis to be done, but I thought this was a necessary (and interesting) first step. 73, John