--- In [email protected], "i2phd" <[EMAIL PROTECTED]> wrote: > > --- In [email protected], "CHARLES HUTTON" <charlesh3@> wrote: > > > > Have I missed something? I don't see any relationship between I-Q > > and sideband suppression. I do see that Rocky - WinRadio - etc. are > > using the I-Q data to achieve image suppression. True sideband > > suppression would involve using a Costas Loop, which I don't see in > > any of the packages. > > > > Chuck > > Chuck, > > there is a bit of confusion on what we are talking about. The > previous three or four messages were related to the crisper quality > the absence of crystal filters, typical of a DC receiver, can give to > the audio. > > The issue of image rejection is a separate one. I don't fully > understand you when you say that "true" sideband suppression can be > done only by using the Costas loop... can you please explain in what a > "true" image suppression done with the Costas loop differs from the > image suppression done by a software program that extracts the > information from a phasor described by its two rotating components I > and Q ? > > 73 Alberto I2PHD
I think that the problem comes from the term sideband. With SDRs the term sideband is used as sideband relative to the LO frequency. In a superhet it is refered as the image. I think that Chuck understood the term sideband as sideband relative to the supressed carrier of a SSB transmission. He wrote "using the I-Q data to achieve IMAGE suppression" and "True SIDEBAND suppression would involve using a Costas Loop". Jean-Claude PJ2BVU
