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technicians. At the beginning of the season data were recorded during storm Period 2 (Fig. 1), but shortly thereafter the radar experienced the failure of several maj or components. These failures were apparently caused by high voltage being applied to the circuits as a result of the failure of a voltage regulator on the main DOT diesel generator. Neither the power generator nor the radar itself has a high voltage protection circuit..._...:!1:l..!..:_~~~: was inoperative from about 24 January until 5 February. The logrithmic intermediate frequency amplifier, the mixer amplifier, and the analog to digital converter were all replaced with similar parts taken from the DRI radar in Reno. Calibrations on the Utah Ka-band radar were performed prior to initial data collection and following the replacement of the major components. The latter calibration showed that the radar was slightly less sensitive (1-2 dB) after the repairs were made in early February. Numerous minor problems with the data recording system were corrected in March, but these resulted in very little data loss. The automatic frequency control (AFC) was a constant problem during operations, in that it would generally not stabilize. This made it necessary for the operator to monitor the transmitter frequency on a regular schedule, and manually adjust or peak the frequency as necessary. The AFC circuit will need to be repaired (or put into a more temperature-controlled environment) in order to improve its operation and avoid the need for manual adjustments. E. Microphysics Data The ORI provided a photographic shadowbox device for periodically recording images of ice particles falling at the DOT site. Ice particles were collected for a known period of time on a glass plate at the top of the box. A Polaroid fi1mback (format 4x5 inches) was then firmly fitted between pieces of felt to 22 I I I I I I I I I I I ,I I I I I I I I