Very long baseline Michelson interferometry measurements were made on Io-related radio emissions from the planet Jupiter at 34 MHz. The data include a single baseline observation made on December 1, 1968, between the Arecibo Ionospheric Observatory (AIO) and Boulder, Colorado (436,000 λ), and a three-station observation made on April 27, 1969, between the University of Maryland Radio Observatory in California, the University of Texas Radio Astronomy Observatory (UTRAO) in Texas, and Boulder, Colorado (typically 100,000 λ). Frequency analysis of the cross-correlated signals shows that there is a tendency toward lower observed fringe rates than had been calculated. If we interpret the results entirely in terms of source motion, the data imply a velocity near 200 km/sec eastward. We attribute the phase fluctuations in the cross-correlated signals to interplanetary scintillation; however, source motion effects cannot be distinguished from scintillation. The implied rms phase variations at the scintillation screen are 0.7 radian at an elongation of 65° (December 1, 1967) and 0.3 radian at an elongation of 145° (April 27, 1969).