A correlation between the solar activity regtons and the Pioneer V interplanetary magnetic field measurements is presented for the months February through May, 1960. The usual 27-day coronal periodicity can be seen in this interval. The corresponding vaiues of coronal index and field magnitude are plotted against each other and the ratio of the field over the index is 0.87. Plausibility of the correlation presented is strengthened by comparison of a more detailed version of spacecraft measurements with chromospheric conditions. (C.E.S.)