  We present multi-frequency observations with the Very Long Baseline Array of
the compact double radio source B2 2050+36. Our observations are at 0.33, 0.61,
1.67, 2.3, and 8.4 GHz, with the 0.61 GHz observations forming the third epoch
of observation of this source at that frequency. At 0.61 GHz, the structure of
B2 2050+36 is dominated by two components 56 mas apart. Within the
uncertainties of the various measurements, this separation has remained
unchanged for the past 16 years. Any differential image wander caused by
refractive interstellar scattering is less than 4 mas. Both the lack of
differential image wander and the frequency dependence of the angular diameter
of B2 2050+36 below 1 GHz indicate that the electron density power spectrum
along this line of sight has a spectral index near the Kolmogorov value, with a
value of 4 being highly unlikely. We conclude that diffractive scattering
dominates along this line of sight; results in the literature indicate that
this conclusion also holds true for the line of sight to the pulsar PSR
B2020+28 (8.7 deg. from B2 2050+36). Comparison of our 1.67 GHz observations
with those obtained 21 years previously place a limit on the projected linear
separation velocity of the two components of c.
