VLBI observations of a complete sample of radio galaxies. VIII. Proper motion in 3C 338

We present new VLA, MERLIN, and VLBI images for the radio galaxy 3C 338 and the results of the monitoring of its arcsecond core flux density. Present high-sensitivity observations allow us to investigate the radio structure of this source and to confirm the presence of two symmetric parsec-scale jets. Morphological changes between different epochs are evident, and a proper motion with ~ 0.4 h~l has been derived. This allows us to give a lower limit for the Hubble constant. While the steep-spectrum largescale structure of 3C 338 could be a relic emission, the small-scale structure looks young, similar to the high-power medium-sized symmetric objects (MSOs) found at high redshift. © 1998. The American Astronomical Society. AH rights reserved.