NASA/Ames Research Center, JA:M/S 241-1, Moffett Field, CA 94035-1000

66 -- WATER VAPOR MONITORING RADIOMETER ASSEMBLY SOL RFQ2-36686-SLC DUE 092998 POC Sharon L. Connolly, Contracting Officer, Phone (650) 604-6927, Fax (650) 604-4646, Email sconnolly@mail.arc.nasa.gov WEB: Click here for the latest information about this notice, http://nais.nasa.gov/EPS/ARC/date.html#RFQ2-36686-SLC. E-MAIL: Sharon L. Connolly, sconnolly@mail.arc.nasa.gov. THIS NOTICE CONSTITUTES AMENDMENT NO.1 TO THE COMBINED SYNOPSIS/RFQ FOR WATER VAPOR MONITORING RADIOMETER ASSEMBLY. Companies shall acknowledge all amendment(s) in their quote. This notice serves as the official amendment to subject synopsis/RFQ and a written amendment will not be issued. The purpose of this amendment is to provide additional information to all interested quoters as a result of questions submitted: Question: For the primary aperture size of this system, about 4 inches, it would be feasible to use a full-aperture calibration target, external to the primary reflector. The reflector could then be periodically rotated to view the load, instead of using a separate flip mirror. This would potentially provide more accurate calibration, but requires a larger calibration load. Is this an acceptable option to consider? Answer: Although a full-aperture calibration target will lead to more accurate calibrations, space considerations in the aircraft mounting preclude using this design. Therefore this is not an acceptable option. Question: What is the requirement for gain stability? Answer: The I/F amplifier gain stability is 0.02 dB/0C or better. Question: In view of the 20 year life requirement, would provision of spare parts or assemblies, or selected built-in redundancies be advisable? Answer: Spare parts and assemblies may need to be subsequently ordered to meet the 20 year life requirement, however, such parts and assemblies are not part of this procurement. Built-in redundancies would be desirable, so long as they do not significantly increase the costs of the procurement. Question: The frequency stability requirement of 1 PPM is an important design driver. We assume this is over the entire temperature range (10 degrees to 40 degrees C), rather than per degree. There is no question of feasibility, but it significantly impacts cost. Is it certain that this is a firm user requirement? Answer: This is a firm requirement over the temperature range. Phase-locked loop local oscillator designs can easily meet this requirement. Question: What is the expected role of the contractor in supporting installation and tests on the aircraft, and for continuing support and services? Answer: Beyond post-delivery technical support involving answering questions submitted via e-mail or telephone, no contractor role is expected in the installation or tests on the aircraft. Question: Does the assembly include a bandpass filter at the IF output? Answer: No The due date for receipt of offers is not extended. Companies shall provide the information stated in the synopsis/RFQ posted on the NASA Acquisition Internet Service (NAIS) on September 11, 1998 related to this procurement are available over the Internet and are in Microsoft Office Suite (Word 6.0, Excel 5.0, or PowerPoint 4.0) format and reside on the World Wide Web (WWW) server which may be accessed using a WWW browser application. The WWW address or URL of the NASA/ARC Business Opportunities home page is http://procurement.nasa.gov/EPS/ARC/class.html. Posted 09/22/98 (D-SN252852). (0265)

Loren Data Corp. http://www.ld.com (SYN# 0225 19980924\66-0003.SOL)