Recent improvements in hardware, software and mixers have made possible frequency switching with satisfactory baselines. Several limitations exist e.g. in terms of frequency throw (max. 45 km/s), backends, phase times etc. For details see . Frequency switching is now open for public use. The receivers 3 mm, 230G1 and 2mm can be frequency switched simultaneously. However, baselines may be better when using only the 3 mm and/or the 230G1 receiver(s) due to the different optical setup.
An instantaneous IF bandwidth of 1 GHz is available for the 230G2 receiver. The two 1 MHz filter banks (512 MHz each) can be combined to provide 1 GHz bandwidth. The use of the 1 GHz wide filter bank excludes the simultaneous use of any other backend with the 230G2 receiver (the other receivers are not affected).
Most proposals submitted for the 30 m telescope underestimate the observing time needed to carry out the programme, even under excellent weather conditions. We ask you to pay special attention to this matter as time underestimation is now a major criterion for proposal rejection (several programmes have recently been rejected by the Program Committee on that ground). A technical report has been issued to assist you , and you may also ask for IRAM's assistance (but well before the deadline!).
Finally, to help us keeping up a computerized source list, we ask you to fill in your `list of objects' as explained below.