Smithsonian Astrophysical Observatory, 60 Garden Street, M/S 22, Cambridge, MA 02138-1516

99 -- PRECISION ALTAZIMUTH POSITIONER SOL RFP-BF3620 DUE 070999 POC POC: EJ Dotts, 617-496-7562, 617-496-7978 (fax), edotts@cfa.harvard.edu/Contracting Officer: Priscilla O. Waltner, 617-495-7401, pwaltner@cfa.harvard.edu The Smithsonian Astrophysical Observatory (SAO) requires the fabrication and delivery of one Precision Altazimuth Positioner. It will be of the traditional alt-az configuration and must be designed to support a balanced precision reflector of 30 kg and diameter 0.6 m. The structure of the Positioner and the beam conduit will be aluminum. The total dimensions are very roughly .9 m high by .64 m wide by .14 m deep. The exact dimensions with drawings are included in the solicitation package. The elevation bearings and elevation drive must have a clear passage of 80 mm and the azimuth bearing must have a clear aperture of at least 80 mm to allow the signal beam to pass. The fork supporting the elevation bearings must allow for a clear passage of 400 mm between its arms and the beam waveguide axis should be 390 mm below the elevation axis. The range of motion of the azimuth is + and -- 170 degrees and + and -- 90 degrees for the elevation. The hysteresis is 1 arcsec for the azimuth and elevation. The axis wobble for the azimuth and elevation is + and -- 2 arcsec. The bearing concentricity is 2 microns for the azimuth and elevation. The azimuth and elevation axes must intersect to within 100 microns. Each axis will be fitted with a home marker with an accuracy of + and -- 4 arcsec with logic output. The elevation home position will be set at 0 degrees with respect to zenith. DC servomotors will drive both the azimuth and elevation axis. Brushless motors are preferred for reliability at high altitude. Both motors will be equipped with rotary encoders to provide a minimum resolution of 2 arcsec and a rotational accuracy of + and -- 4 arcsec at the azimuth and elevation axes. The slew speed will be 20 degree/sec for the azimuth and elevation. The azimuth will have a limit switch of + and -- 170 degrees. The elevation, with respect to zenith, will have a limit switch of + and -- 91 degrees. A generic hardware interface between the motion controller and computer, such as RS232, IEEE488, or Ethernet, is required so that the system may be used with a variety of operating systems. The antenna system will be integrated into a standard ISO shipping container (6.06 m long x 2.44 m wide x 2.59 m high) and will be supported such that the azimuth bearing of the antenna mount is close to the roof level. All components above the azimuth bearing will be subject to external weather conditions whereas those below the azimuth bearing, including drive electronics, will not. The complete antenna system will be operated remotely and will therefore be left unattended for long periods of time, typically several months. Therefore, the antenna drive must be sealed against adverse weather conditions. System operations can be defined as follows: 1) survival conditions during which the antenna mount will be expected to survive 50 m/s winds and suffer no deterioration in performance when the temperature cycles between -40 and +40 C; 2) degraded operation during which a two fold degradation in pointing or positional accuracy will be tolerated for winds up to 14 m/s and throughout the extended temperature range of -30 to +30 C; and 3) normal operation during which the antenna will be expected to achieve specified positional accuracies under normal operation, light winds of less than 5 m/s and throughout the temperature range of -20 to +30 C. Since the antenna will operate from a remote mountain site, altitude 5,500 m, minimizing power consumption is a requirement. System operations will be via a 24-Volt bus. Offers will be evaluated on price, technical proposal, delivery schedule, and past performance. The anticipated award date is 6 August 1999. The order is to be delivered FOB destination to SAO in Cambridge, MA. The desired delivery date is 7 weeks ARO. Only written, fax, or email requests for a solicitation received directly from the requester are acceptable. No telephone requests for the solicitation will be accepted. All responsible sources may submit an offer. This acquisition is being conducted under FAR Part 12, Acquisition of Commercial Items, and FAR Part 13, Simplified Acquisition Procedures. Posted 06/11/99 (I-SN342125). (0162)

Loren Data Corp. http://www.ld.com (SYN# 0316 19990615\99-0007.SOL)