Cross Country Wireless Sentinel HF SDR Noise Measurement receiver and program
We have now released the Sentinel SDR noise measurement receiver and SDR program to accurately measure the HF noise floor and send telemetry reports by APRS.
The Sentinel receiver and program also works well as a general purpose SDR receiver covering 2 to 15 MHz.
The MMVARI digimode program is built into the Sentinel SDR program to allow decoding of PSK, QPSK, RTTY and GMSK HF data modes using the PC internal sound card.
Recent telemetry reports from a prototype receiver can be viewed here. Results after 6 January use the current software and frequency list.
The software scans five HF frequencies and provides the peak, median and minimum levels of 500 measurements per frequency every 10 minutes. The receiver bandwidth is 500 Hz.
The five frequencies used are:
3.499 MHz just below the 80m amateur band
5.258 MHz just below the 60m amateur allocation
6.999 MHz just below the 40m amateur band
10.090 MHz an unused frequency in the aeronautical mobile allocation
13.400 MHz in the radio astronomy allocation
As the receiver uses a built-in sound card the calibration is independent of the PC
used and it will be supplied with calibration information traceble back to National Standards. This will allow the RF level and frequency measurements to be
calibrated to a professional standard.
The program uses serial port control of the DDS synthesiser. The program runs on
Windows 2000 or Windows XP with a low CPU load so that older PCs and laptops can be used.
A beta version of the Sentinel SDR program can be downloaded here. Unzip the file as a folder, move the folder to the C: drive and open the .EXE file in the folder.
A FAQ sheet for the Sentinel receiver can be downloaded here.
This development ties in with the Noise Measuring Campaign recently launched by Gwyn Williams, G4FKH of the RSGB Propagation Studies Committee. The Noise Measuring Campaign records HF noise levels regularly recorded by many participating radio amateurs.
This development will add a number of calibrated noise measuring receivers to provide additional information to the project.
More information on the Noise Measuring Campaign is available here.
Contact Chris Moulding, G4HYG via info@no_spam_crosscountrywireless.net for more details.
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