HF Spectrum Monitor Technical Information
Location : Central Southampton, UKThis website allows you to connect to and control a wideband software defined HF radio receiver connected to this server. It offers a full 30MHz instantaneous view of the HF spectrum, which can be zoomed to show bands in detail. You have tuning control of one of the receiver's DDC tuned channels. You can view the narrowband spectrum in this channel, and listen to the output of a demodulator via streaming audio.
All the data collection, processing and graph creation is performed on the server, with the browser acting as a display and request interface. The system is free to use and no login details are required. When you load the viewer, you will be allocated a temporary ID that allows you to tune one channel and view the tuned and wideband spectra.
Note that all content on this site is now served from a dedicated web server on Port 8080. This serves all the pages you see here plus the MP3 streaming audio. The HTML5 viewer has been tested (October 2018) with Firefox, Edge, Chrome and Opera.
Queries and suggestions may be sent to
Note that some man-made interference (QRM) is seen from VDSL signals on nearby phone lines.
A 7 day 24 hour zoom-able waterfall display shows a chosen section of the spectrum built up from snapshots taken at 2 minute intervals. The "live" page shows data over a rolling24 hours (data from 00:00 UTC to "now" from today, data from "now" to 23:59 UTC from yesterday). Previous days completed spectra may be selected for comparison. Fully zoomed resolution is approximately 380 Hz / bin (windowed).
Hardware and software details