10.5281/zenodo.834947
Reyer, Steven
Steven
Reyer
Wwv 15 Mhz Reception Test -- 60 Minutes Starting At 1937 Utc, July 25, 2017.
Zenodo
2017
WWV "solar eclipse" "spectrum lab"
2017-07-26
https://zenodo.org/record/834948
10.5281/zenodo.834948
Creative Commons Attribution 4.0
Open Access
<p>Steven Reyer, WA9VNJ. Approx.Lat/Long: 43.218, -87.951. This 60-minute 15 MHz WWV recording was started at 1937 UTC on July 25, 2017, in preparation for the Solar Eclipse experiment in late August.</p>
<p>The radio is a Yaesu FT-857D locked to a Trimble Thunderbolt GPSDO using an XRef-FT oscillator interface. Antenna is an RF-PRO-1B shielded magnetic loop, aimed N-S. Calibration of the radio and sample rate correction is determined using a second Trimble Thunderbolt GPS and Rigol DG1022Z GPS-locked signal generator.</p>
<p>Spectrum Lab software is used to record the WAV file and to analyze incoming audio with sample rate of 11025 Hz. FFTs are 512k-point, 75% overlapping, yielding a new measurement every 12 seconds. Radio is tuned to 14999.00 kHz USB yielding audio around 1kHz (labeled "PeakFreq" in the txt file). Thus, the measured radio frequencies are near 15000 kHz. Calibration tests show that the audio frequency measurements are approximately 0.0384 Hz high, due the approximations in both the radio's DDS and the sample rate. This 0.0384 Hz number can be subtracted from the PeakFreq values to get corrected audio frequencies, which can then be added to the 14999 kHz number.</p>
Signal was moderately strong for the full 60 minutes, with some fading.