Mauna Loa Solar Observatory Observer's Log ----------------------------------------------------------------------------- Sun Apr 23 16:50:39 GMT 1995 Year: 95 Doy: 113 Observer: yasukawa console Apr 23 16:40 WEATHER COMMENT: Sun Apr 23 16:50:58 GMT 1995 Cold, clear, no wind at this time. Cloud bank to east quite high. Temp=34F, relative humidity 70%. COMMENT: Sun Apr 23 16:52:13 GMT 1995 Island-wide power outage yesterday evening. Internet connection still out, as evidenced by slow startup of Sparcstation this morning. LOW-L COMMENT: Sun Apr 23 16:53:41 GMT 1995 Lowl was restarted and taking data on unit 0. Since there were numerous problems yesterday, and the data has already been overwritten at the beginning of the tape, I decided to just let it continue on L00224. Sun Apr 23 16:55:59 GMT 1995: Patrol Start DPMON COMMENT: Sun Apr 23 16:59:07 GMT 1995 Optics runaway. Resetting manually. Sun Apr 23 17:01:43 GMT 1995: Patrol Start COMMENT: Sun Apr 23 17:05:48 GMT 1995 Network check with ping command indicates connection between MLO router on mountain and MLO at FB is down. DPMON COMMENT: Sun Apr 23 17:37:59 GMT 1995 Daystar runaway, reset Plessey. Sun Apr 23 17:40:10 GMT 1995: Patrol Start DPMON COMMENT: Sun Apr 23 17:40:18 GMT 1995 Had to use manual control to reset. Objective had run away also. MKIII COMMENT: Sun Apr 23 17:44:53 GMT 1995 Vdiff check shows streaking occurring. Will try an ALLFRESH attempt to see if problem is with correctors. MKIII COMMENT: Sun Apr 23 17:51:40 GMT 1995 By applying ALLFRESH to CORONA trace, streaking clears up briefly. Check of VDIFF indicates no fix. Sun Apr 23 18:02:05 GMT 1995: Calibration MKIII COMMENT: Sun Apr 23 18:12:36 GMT 1995 Swapped AN4 card (A/D converters) in channel 2 analog (micro 0) with a known good spare. MKIII COMMENT: Sun Apr 23 18:22:15 GMT 1995 Streaking still present. Swapping AN4 back. Swapping AN2 (MDACs) as a next step. MKIII COMMENT: Sun Apr 23 18:37:47 GMT 1995 That may have been it! Replaced AN2 card in Analog chan 2 (Micro 0) with a known-good spare. That cleaned up the streaking. Will run for a while to make sure that cycling the power is not the cause of the "fix". Upon close examination of the "faulty" AN2 board, one of the filter capacitors between the ground plane power and ground is very fuzzy with corrosion, probably from leaking electrolyte. MKIII COMMENT: Sun Apr 23 18:48:08 GMT 1995 Latest VDIFF with first scan indicates that streaking my be returning. This indicates that the cycling of the power may have temporarily fixed the problem. At this time the streaking signature is very subtle so I will run a bit longer before attempting other things. Sun Apr 23 19:01:59 GMT 1995: Calibration MKIII COMMENT: Sun Apr 23 19:36:15 GMT 1995 At this point, methinks that the subtle streaking might just be a touch of paranoia and the sky getting a bit noisy. Will keep up vigilance. COMMENT: Sun Apr 23 19:47:25 GMT 1995 Opening top of dome. Sun Apr 23 20:02:01 GMT 1995: Calibration MKIII COMMENT: Sun Apr 23 20:13:17 GMT 1995 Inspected suspect AN2 board further and found that negative lead to filter capacitor broke off at touch underneath all the corrosion. Removed capacitor and replaced it with closest substitute available, a 10mfd-35V tantalum. Will need to test board before adding it to spares inventory. MKIII COMMENT: Sun Apr 23 21:01:37 GMT 1995 Sky very noisy. Stopping MKIII exabyte while trying a couple of tests to see if streaking fix worked. WEATHER COMMENT: Sun Apr 23 21:35:52 GMT 1995 In orographic clouds. Sun Apr 23 21:37:04 GMT 1995: Patrol End MKIII COMMENT: Sun Apr 23 21:42:29 GMT 1995 Tried looking at VDIFF comparing two opal-in scans. That subtle streak/noise is present in outer 1/4 of scan. Tried swapping the analog corrector memory cards and repeated opal-in/VDIFF test and results were the same. Outer noise may be an effect of detector misalignment, pixel noise in the outer pixels, or some combination of alignment and corrector values. Clouds came in so further tests were not done, although it was not really clear to me what I was planning to do next. MKIII COMMENT: Sun Apr 23 21:46:56 GMT 1995 Restored the corrector memory boards. COMMENT: Sun Apr 23 21:47:21 GMT 1995 Activity report: Nice prominences on west limb, got carried away with streak investigation, forgot to note down their PA. No coronal activity. COMMENT: Sun Apr 23 21:48:36 GMT 1995 Tapes: MKIII: H01016 DPMON: P00337 LOWL: L00224 Sun Apr 23 21:50:10 GMT 1995: Filemark SCAN-LOG SCAN-LOG 16:50:19. 4/23/95 DOY 113 17:04:51 17:08:02 17:11:15 17:14:26 17:17:40 17:20:50 17:24:01 17:27:10 17:30:22 17:33:32 17:36:44 17:39:56 17:43:09 17:46:21 17:49:34 17:52:45 17:56:02 18:14:47 18:17:58 18:27:26 18:30:37 18:33:53 18:37:04 18:40:16 18:43:26 1847 0 CL 18:50:54 1856 15CL 19:02:16 19:06:16 19:09:27 19:12:40 19:15:50 19:19:01 19:22:11 19:25:23 19:28:33 19:31:46 19:34:57 19:38:08 19:41:18 19:44:29 19:47:38 19:50:49 19:53:59 19:57:11 20:00:23 20:03:33 20:06:43 20:09:54 20:13:04 20:16:15 20:19:26 20:22:37 20:25:47 20:29:03 20:32:13 20:35:24 20:38:33 20:41:46 20:44:55 20:48:06 20:51:16 20:54:28 20:57:39 21:00:54 0 ERRORS OK