SDR Console Version 3.0.13 brings some neat improvements, especially in signal strength and SNR meters. Check it out yourself.
For a number of years, Simon Brown’s SDR Console has been my go-to software for listening with software defined radios. It works with most popular receivers and does a great job of control, demodulation and display. What’s more, Simon makes this professional-grade program available to hobbyists at no charge.
Recently, I updated to SDR Console Version 3.0.13 released in August. I discovered some wonderful enhancements in the “S-Meter”. In the past, SDR Console has always provided choices for display of dBm, dBμV and S-units. But now, there are two additional metering improvements.
On the aesthetic side, you now have a choice of digital or analog meter, shown above. On the functional side, you can also see noise level as well as signal strength.
If you look at the picture above, on the left side the meter shows peak signal (red), current strength (yellow) and noise floor (grey). On the right hand side, the meter shows signal to noise ratio. In this case, I am receiving Radio Saudi with a 61 dB SNR, which is great.
Unfortunately, the signal history graph only shows signal strength. A future improvement to provide a time series display of SNR would be nice.
SDR Console Version 3.0.13 Improvements – Measuring Noise
In the past, I have always had to estimate SNR in my head. I did this my visualizing the average noise floor in dBm, and subtracting the signal strength in dBm. The result is approximate signal to noise ratio in dB.
This is essentially what Simon now does in software. First, he discards the outer 30% of the FFT spectrum measurements. This gets rid of overlap-add artifacts. Then, he sorts all the FFT bins, and takes the mean of the lowest 10% to approximate the noise floor.
The averaging approach will work pretty well on spectrum that is not too crowded, and is easy and fast to implement.
I am not sure how well it will work on the crowded AM broadcast band where there is lots of leakage in the FFT, but we will see.