In the AM broadcast band (535-1705kHz), there are roughly two modes of broadcast station signal coverage, one of which occurs in the daytime, and the other at night. During the day time, signals are propagated by ground wave and and not usually heard well beyond 150km from the transmitter. However, at night, an absorptive region in the ionosphere, the D-layer, disappears, allowing signals to refract off higher regions of the ionosphere, and to be heard hundreds and even thousands, of kilometers away from the transmitter. During the solar eclipse of 21 August 2017, signals were observed changing from daytime to nighttime mode and then back again as the moon's shadow moved across the continental USA. The radio stations in this band use amplitude modulation, which requires a strong stable carrier wave, well suited for observing changes in signal strength over a time period. Included in these files are an installation file for SpectraVue 3.39 ("spectravue339.exe") for playback of the .wav files, courtesy of RFSpace, an .ini file to be used with SpectraVue after it has been installed ("CloudIQ_playback.ini"), plus a reference file to assist in identifying signals ("canusa-Jan2019.pdf"). As well, there is set of instructions for installation and use of the software, including instructions for using SpectraVue to extract a time series of signal power for an individual radio station's signal ("Using SpectraVue to create signal strength time series-N7NZH.pdf"). Finally, referencing the article archived at http://hamsci.org/sites/default/files/publications/2019_am-eclipse2017_hall-patch.pdf , will give the user of these files an idea of how radio reception datasets from different locations can be used to compare the effects that the solar eclipse had on radio propagation.

recorded by Dave Aichelman, N7NZH location recorded: 42° 24.800'N 123° 23.314'W These data files are recordings that include the entire medium wave broadcast band (535-1705kHz) from 17:09:00UTC to 17:46:00UTC, recorded in Grants Pass, Oregon, U.S.A.. Data files are .wav format, but the archived files are .zip, with several .wav files packaged together in each .zip file. Antenna: Wellbrook 1530LN Loop (https://www.wellbrook.uk.com/loopantennas/), oriented east-west; Receiver: RFSpace (http://www.rfspace.com) Cloud-IQ SDR, 10dB attenuation, center frequency set at 1120kHz, recording 1500kHz wide passband, using RFSpace SpectraVue v.3.39 software (http://www.rfspace.com/RFSPACE/SpectraVue.html).