Measurements of the carrier frequency of the NIST radio station WWV on 10 MHz, as performed in north suburban Milwaukee, Wisconsin, during the solar eclipse of August 21, 2017. Details are in the file "readme.pdf". Steven Reyer, WA9VNJ, approx. Lat/Long = 43.218, -87.951. WAV file start time = 1400 UTC. Antenna is a DX Engineering RF-PRO-1B aimed north-south, receiver is a Yaesu FT-857D locked to a Trimble Thunderbolt GPS via an XRef-FT oscillator interface. I tuned the radio to 9999.00 kHz USB and listened for the resulting nominal 1000 Hz tone, which was measured by Spectrum Lab software, doing 512k-point FFTs, overlapping 75%, resulting in a measurement every 12 seconds.

An interesting "up and down" variation in frequency occurred during the eclipse time, which was not seen on the Control data from the previous day. See the eclipse_day.jpg and control_day.jpg files, or the eclipse_compare.xlsx spreadsheet.