On 03/09/17 20:38, Wes Stewart wrote: > The K3S blanker is slightly better than > useless. When I set it aggressive enough to be audibly useful, FT8 > decodes multiple signals at 120 Hz intervals, which upsets sequencing.
That's an inevitable consequence of how a noise blanker works. It removes power line noise by muting reception 120 (or 100) times a second, corresponding to peaks in the power line voltage when the arcing occurs. If you chop an audio tone up at 120 Hz, you are amplitude modulating the tone with a 120 Hz waveform. That produces sidebands either side of the tone 'carrier'. This is why you should never use a noise blanker with FT8 and similar modes. The best way to use a rig with WSJT-X is, generally speaking, to make the computer do as much as possible and make the rig do as little as possible. Treat it more or less as a dumb transverter. Don't use the noise blanker, don't reduce the bandwidth below about 2.5 kHz, don't use the notch filter. WSJT-X's decoder works best if you just get the level about right and let it deal with the QRM. 73, Richard G4DYA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
