  We determined the separations of the radio sources in the triangle formed by
the BL Lac objects 1803+784 and 2007+777, and the QSO 1928+738 from
intercontinental interferometric observations carried out in November 1991 at
the frequencies of 2.3 and 8.4 GHz simultaneously. We successfully connected
differenced phase delays over 7^o on the sky at 8.4 GHz at an epoch of maximum
solar activity. The effects of the ionosphere on these VLBI data were mostly
removed by estimates of the total electron content from observations of GPS
satellites. The comparison of the estimated separation of QSO 1928+738 and BL
2007+777 with previous such estimates obtained from data at different epochs
leads us to a particular alignment of the maps of QSO 1928+738 at different
epochs relative to those of BL 2007+777, although with significant uncertainty.
For this alignment, the jet components of QSO 1928+738 show a mean proper
motion of 0.32+/-0.10 mas/yr and also suggest an identification for the
position of the core of this radio source.
