Lambda 6-cm observations of fluctuations in the 3K cosmic microwave background.

The design and execution of the first in a series of experiments to measure fluctuations in the cosmic microwave background (CMB) at a wavelength of 6 cm on angular scales from 10 to 60 arcmin are described. It is noted that at this wavelength the atmosphere has a negligible effect on the observations, and a high degree of repeatability in the data is demonstrated. Particular attention is given to identifying and then eliminating systematic effects which have limited previous experiments. These effects repeat in hour angle (HA) and derive from the telescope environment. The statistical procedures used are discussed in detail so that the results can be compared critically with earlier work. The removal of systematic effects arising from the HA baseline and known sources in the field is described, together with the hypothesis tests required in obtaining an estimate of the CMB fluctuations. A description is also given of the derivation of fluctuations on scales larger than the beam.