K3 Transmit Equalization / Filter Offset

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K3 Transmit Equalization / Filter Offset

Julian, G4ILO
Can someone explain the siginificance of the filter offset specified on the 2.7KHz 5 pole filter and the implications of changing CONFIG:FLx FRQ for audio equalization?

I happened to notice in the docs a suggestion to equalize the transmit audio on LSB by changing the value of CONFIG:FLx FRQ. The audio on 14MHz USB was fine but on LSB it seemed a bit harsh and shrill, so I decided to try this.

The number written on my filter was -0.89. After a couple of hours of testing (during which the wife must have thought I'd gone mad) I found that both sidebands pretty similar with FLx FRQ set to -0.72, but that I had compromised the quality of the USB audio in order to achieve this.

Does the K3 switch sidebands so that the USB setting on 14MHz will be used for LSB on 40m? In other words, since the opposite sideband is practically never used, would it be best to leave CONFIG:FLx FRQ at the default setting that gives the best results for the mode most commonly used and not worry about the other sideband?
Julian, G4ILO. K2 #392  K3 #222 KX3 #110
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