Been wondering how WSJT-X generates the noise power estimate it uses to calculate SNR for each FT8 signal. Does it simply collect all the signals and noise over the bandwidth selected on the waterfall and call that the noise power level or does it take a quick snapshot of the background noise level during the brief quiet period at the end of each 15 second FT8 sequence? Or is it more complicated than that?
I am plagued with a S2 -S3 noise level on 6 meters nearly all the time that if not AWGN is pretty close to it. 10 meters is even worse. The DSP noise blanker in my TS590 will reduce it slightly. I estimate this is degrading my ability to decode FT8 signals on 6 by nearly 20 dB compared to the noise level generated by a 50 ohm resistor. I don't use an LNA ahead of the radio - would be pointless. I don't use the noise reduction feature in the radio either as it tends to lose very weak signals completely. Wondering if I can use the DSP in my TS590 to narrow the receiver bandwidth to perhaps 300 -500 Hz around a known offset to help pick weak signals out of the noise? I realize that the WSJT program filters the audio into much narrower BW bins so all the receiver filtering can do is reduce the receiver gain reduction caused by the noise pumping up the AGC but that might be beneficial. Likewise, would using the DSP notch to suppress a single strong local signal or birdie help since strong signals also reduce receiver gain? Should I deselect the flatness option if I use these tools? Would narrowing the waterfall span help any since the program ignores anything outside that span? Would appreciate any insight you can share. Joe W0FY
_______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
