National Optical Astronomy Observatories, 950 N. Cherry Ave., Tucson, AZ 85719
The first T&E observing run employing the nod-and-shuffle technique with the RC Spectrograph on the KPNO 4m Mayall Telescope was successful. Using this technique, we were able to achieve accurate subtraction of strong telluric lines (as well as the fringing in the red) to better than XX%, thus reaching the shot noise limit for spectroscopy. The overhead on the mode is large, but the new scientific capabilities enabled (increasing target density on the mask, improving sky subtraction for faint targets, spectroscopy of diffuse emission) more than compensate for the overhead. We suggest some ways of reducing the overhead. A second T&E run in fall will be required to conduct further tests of the system before it may be declared available for general use.