  The results of speckle interferometric observations at the 4.1 m SOAR
telescope in 2016 and 2017 are given, totaling 2483 measurements of 1570
resolved pairs and 609 non-resolutions. We describe briefly recent changes in
the instrument and observing method and quantify the accuracy of the pixel
scale and position angle calibration. Comments are given on 44 pairs resolved
here for the first time. Orbital motion of the newly resolved subsystem BU~83
Aa,Ab roughly agrees with its 36 year astrometric orbit proposed by
J.~Dommanget. Most Tycho binaries examined here turned out to be spurious.

Solar and Stellar Astrophysics