Abstract
We present our analysis of the neutron monitor data observed at Deep River and Huancayo over a time span of 25 years. The median primary rigidity of response (R(m)) for these detectors encompasses the rang: 16 GV less than or equal to R(m) less than or equal to 46 GV. The daily average values of cosmic ray counts have been harmonically analyzed for each 27-day solar rotation during the period 1964-1988. The amplitudes of both the 13.5-day and the 27-day have been determined for each solar rotation. Both amplitudes display an 11-year sunspot cycle variation, with minima occurring near sunspot minimum and maxima occurring near sunspot maximum.