During the coming semester we expect the New Control System (NCS) to go into operation. CAMAC interfaces and VAX computers will finally be retired. Hardware control will be through VME based systems, mostly running Linux, and all user-interface and data processing software will run on Linux.
The transition to the NCS is planned in two major steps. First, starting in the second half of September, NCS version 1 will be installed and tested, supporting a subset of features identified as ``essential''. Most current observing modes, including on-off, wobbler switching, and on-the-fly maps, will be available for bolometers, single-pixel SIS receivers, and HERA. We are reviewing a detailed list of these ``essential'' features of NCS v1 and will publish it on the IRAM web site.
Other observing modes and new features will be made available in a second step, for which the details and timing will depend in part on the demands of the new proposals. We therefore expect that a few proposals requesting rare observing modes not included in NCS v1, may experience scheduling constraints.
Working with the NCS will be easy for observers used to the current control system, although some commands will change in order to support new features. A user's guide for the NCS will be available before any projects get scheduled under the NCS, and we will provide special support for observations with the NCS.
The extended tuning range of the 3mm receivers (down to 77 GHz in LSB with good USB rejection, and near-DSB operation in the 72 - 77 GHz range) is now routinely available, with the proviso that a 1.3mm receiver housed in the same dewar as a 3mm receiver used below 80 GHz is not available. No hardware modifications are needed anymore. However, due to the rapid variation (with frequency) of the sideband ratio, special care must be taken with calibration. Recipes are described in a test report (available at ../IRAMFR/PV/veleta.htm). The report also contains a collection of 72 - 80 GHz reference spectra. Proposers should use the time estimator which will include the correct receiver temperature at the low frequencies and an extra overhead for calibration.
The dual polarization HERA started to give satisfactory results at the time of writing. The necessary expansion of the IF distribution system is made, and the backend WILMA has been debugged. Residual problems (one dead detector, some instabilities) will be investigated this spring.
Like last summer, a bolometer array, most likely the 117-channel MAMBO II which should be used for observing time estimates, will be available. Somewhat depending on the LST ranges requested by the new proposals, one or more smaller sessions of pooled observations will be scheduled.