1、Lessons Learned Entry: 0381Lesson Info:a71 Lesson Number: 0381a71 Lesson Date: 1995-02-13a71 Submitting Organization: JPLa71 Submitted by: Jim TaylorSubject: Antenna Test Difficulty at Air Force Eastern Test Range Abstract: Although measurements at JPL suggested that the Voyager antenna system and i
2、ts RF probe were not strongly affected by the building environment, the building environment at the test range location caused noticeable RF variations. When planning RF tests in different facilities, pathfinder tests should be conducted. Use RF probes with high directivity and shield the antenna fr
3、om metallic surroundings that cause RF reflections.Description of Driving Event: The extreme Radio Frequency (RF) reflections due to the building environment at the Air Force Eastern Test Range (AFETR) hindered system measurements on the Voyager flight radio and antenna. The intended measurements we
4、re to be made using a small directive RF probe mounted on the antenna reflector. Previous repeatable JPL measurements in the JPL Spacecraft Assembly Facility high bay led to an erroneous assumption that the Voyager antenna system and its RF probe were not strongly affected by the building environmen
5、t. At the AFETR, the location and the movement of overhead cranes caused noticeable RF variations.Additional Keyword(s): Performance VerificationLesson(s) Learned: RF testing can be strongly affected by the building environment.Recommendation(s): 1. When planning RF tests in different facilities, pa
6、thfinder tests should be conducted to Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-minimize loss in measurement precision or to eliminate the need for extensive workarounds.2. In conducting RF tests it is important to use RF probes with high direc
7、tivity and to shield the antenna from metallic surroundings which cause RF reflections.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Test Facilitya71 Test & VerificationAdditional Info: Approval Info: a71 Approval Date: 1989-12-19a71 Approval Name: Carol Dumaina71 Approval Organization: 125-204a71 Approval Phone Number: 818-354-8242Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
