For those that don't follow Elecraft product announcements, last week a public beta firmware was released that contains the much anticipated Spectral Subtraction Noise Reduction, available for usage in all modes. The older Least Mean Squared NR method is still available in the rig, allowing users to switch between the methods, as desired. I've been publicly critical of the older K4 LMS NR method for SSB on user forums and mailing lists, especially for a flagship rig at this price. So when the SSNR firmware announcement was made, I installed it within an hour of its release. Short version: this is a HUGE improvement. I don't what other HF rigs have deployed this technique, but IMO, this development keeps the K4 at the top of the list of Amateur HF rigs.
I made a video comparing the new SSNR with the older LMS that I augmented with a BHI Dual In-Line Noise Eliminating Module. Put some headphones on to hear it well:
If you don't want to watch all the way to the end, I make a note that I took the BHI out of line after this update. Elecraft says that they can add this type of NR to the KX2 and KX3 radios, as well - and may do so in the not-too-distant future after a few other priorities are knocked out.
I made a video comparing the new SSNR with the older LMS that I augmented with a BHI Dual In-Line Noise Eliminating Module. Put some headphones on to hear it well:
If you don't want to watch all the way to the end, I make a note that I took the BHI out of line after this update. Elecraft says that they can add this type of NR to the KX2 and KX3 radios, as well - and may do so in the not-too-distant future after a few other priorities are knocked out.