The MC1496 in an HF I/Q *upconverter *showed the best balance and sideband rejection of any I tried. It does needs a lot of external resistors and presets, but is worth the final effort to end up with a piece of test-equipment-grade hardware.
Not sure I'd want to use one in a receiver though. -- Andy G4JNT www.scrbg.org/g4jnt >Daniel, why don't you put your efforts on a more modern chip, that >art was obsolete 10 years ago. > >Cecil >K5NWA
