As little has changed regarding JCMT instrumentation since the last issue of the Newsletter, only a brief summary is given here. A more complete version of this text is maintained in the e-mail fileserver (ask for file `receivers.summary'). Complete information suitable for preparing proposals can be found in `The James Clerk Maxwell Telescope: A Guide for the Prospective User' which is available over the e-mail fileserver (file `userguide.ps'), or through the offices of the partner countries or from the Joint Astronomy Centre in Hawaii. The User Guide also may be browsed on the World-Wide Web (home page http://jach.hawaii.edu/).

Three SIS mixer receivers form the core of the spectral line program, A2, B3i and C2. One other SIS receiver (G) is available via collaboration with the MPE, Garching group; contact Dr. L. Tacconi

(LINDA@MPE-GARCHING.MPG.EDU)

for further information.

B3i is expected to be replaced by a dual-channel receiver (B3) early in 1995. In the latter part of semester 95A, a dual-mixer dual-waveband SIS system (Receiver W) for the 450-490 and 650-690 GHz windows may be commissioned. Because of the uncertainties in the delivery dates for B3 and W, users are advised to prepare programs which are suitable for the current equipment. See elsewhere in this Newsletter for additional information on these systems.

Until displaced by SCUBA (see below) the UKT14 bolometer system will be available for continuum observations with filter wavebands at 2, 1.3, 1.1, 0.85, 0.8, 0.75, 0.6, 0.45 and 0.35 mm. The aperture of the bolometer can be adjusted between 21 and 65 mm. Sensitivities range from typically 0.3 through to 10 Jy/sqrt(Hz) under good photometric conditions. Photometry is normally carried out with full aperture, and mapping with an aperture matched to the antenna beam. So long as UKT14 is available, the Aberdeen/QMW polarimeter also will be offered as an optional accessory for it. Observations are possible at 1100, 800, and 450 microns.

The submillimetre bolometer camera SCUBA is not expected to arrive in Hilo before spring of 1995. It will not be available for astronomical observations until some time later following a lengthy commissioning period. Regular proposals for the use of SCUBA will therefore NOT be accepted for semester 95A. Additional information appears elsewhere in this Newsletter.

Henry Matthews, JAC