VLF Signals and the SDRPLay RSPdx
A look at how you can receive signals in the Very Low Frequency (VLF) band with the SDRPlay RSPdx Software-Defined Receiver.
SDRPlay RSPdx: The HDR Mode and VLF
RadioUser has occasionally published articles covering the Very Low Frequency (VLF) band (for example RadioUser, August 2019: 24; December 2019: 32). It is in this band where we can hear ionospheric phenomena, time signals stations, military signals from the world’s Navies, experimental transmissions from radio amateurs, and a range of other sounds and signals. Recording and understanding those better allow radio hobbyists to recognize weather, propagation conditions and the Sun’s influence on our atmosphere. The new SRDPlay RSPdx Software-Defined Receiver, reviewed in the January and February 2020 issues of RU (RadioUser, January 2020: 7; February 2020: 14-17) can resolve VLF signals from 9kHz. The various possible settings you can adjust in the SDRuno software allow you to home in on individual signals in detail, record and evaluate transmissions at a later stage, and visualise changes in signals over time. The images here are an overall view of the device and a screenshot of the Time Signal Station MFS-60 in Cumbria.