From analysts@aoc.nrao.eduThu Jul 2 09:40:46 1998 Date: Wed, 24 Jun 1998 08:40:47 -0600 (MDT) From: Data Analysts To: jive@RZMWS0.NFRA.NL Subject: GM035 PI letter Dear PI, We have examined the data for project GM035 on 30 May 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on 1803+784, 2007+777, 0917+624, and M81. 4. Cross-correlation bandpass plots were generated for all baselines to PT for scans on 1803+784, 2007+777, 0917+624, and M81. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: VLBA: SC: OK HN: OK NL: OK FD: OK LA: Wildly varying rates and delays for target source SN93J on baseline PT-LA. PT: The delay is ~80ns with respect to the rest of the array. KP: Wildly varying rates and delays for target source SN93J on baseline PT-KP. OV: OK BR: At the end of the second tape near the beginning of reverse passes, playback is slightly variable. MK: Dead track #8 at 18:14-18:17 UT. VLA27 (Phased Array): Tape was in SEARCH at 11:15-11:47 UT. Variable weights at 17:25-17:50. IFs 1,6,7, and 8 look noisy or are losing signal due to VLA 50 MHz band pass. In the cross-correlation plots there is an increasing phase wind and IFs 7 and 8 are very noisy due to the 50MHz band pass. In the phase, rate, and delay plots the PT-Y baseline is too noisy in IFs 1 and 8 to see. Foreign Stations: EB: OK JB (JB2): In search at beginning of the second tape from 18:03 - 18:16 UT. Strong pcal signals in autocorrelation plots. Missing fringes on PT-JB at 17:45 UT. Noisy on the M81 cross-correlation plots. NT: IFs 1,2,7, and 8 have slightly odd bandpass shapes in autocorrelation plots. IFs 5 and 6 have low power with frequent DC spikes. No fringes in the cross-correlation plots in IF 5 and 6 most of the time. WB: The tape was in SEARCH or had poor playback at 11:45-12:14 UT. Playback was poor on all tracks, especially 20-33, at 16:58-17:25 UT. Variable weights (weak on most tracks) at 18:36-18:38 and 18:53-19:00 UT. All channels were weak (high tracks are poor), 23:49-00:14 UT. Strong pcal signals in auto-correlation plots. Many cross-correlation scans are noisy or missing. Noisy on cross-correlation scans on M81. All foreign stations: Good fringes to all foreign stations exist at some point in the cross-correlation plots. From analysts@aoc.nrao.eduThu Jul 2 09:41:58 1998 Date: Tue, 30 Jun 1998 15:04:12 -0600 (MDT) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@NFRA.NL, jive@RZMWS0.NFRA.NL, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, paragi@aoc.nrao.edu, trigilio@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it Subject: GP017 Feedback Dear PI, We have examined the data for project GP017 on 07 Jun. 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on 3C454.3, 1803+784, 1404+286 & 1823+568. 4. Cross-correlation bandpass plots were generated for all baselines to EF & NL for scans on 3C454.3, 1803+784, 1404+286 & 1823+568. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: VLBA: PT: Missing weights/data at 9:50-10:00. Y: Variable weights at 7:50-8:02. In search 9:26-9:31. Non-uniform and sloping bandpasses in all channels. This is expected due to large bandwidths. NL-Y baseline shows slightly nonlinear phase dependence in all IFs around 12:48. OV: Stalled at 8:40-9:50; weights are 0. This is due to a mini-decoder filtered-time conflict. LA,MK,KP,FD,BR: RFI in IFs 7 and/or 8 at ~12:45 LA: RFI in IFs 7&8 at ~11:11. MK: RFI in IFs 5&6 at ~11:11. SC: Upper bandpass edge problem or RFI in IF 7 at ~11:11. HN & NL: OK NON-VLBA: CM: Variable weights at 22:15-23:00 due to being in search; weights > 75%. In search 5:00-5:40; weights at 0%. IF 6 has an amplitude problem at lower bandpass. EF-CM: only first 4 IFs fringe. IFs 1-4 have a severe non-linear phase dependence with frequency; may have something to do with the microwave data link. EF: Dead on tracks 8-13 at 21:00-22:15; weights at 50%. The tape was moved, but there was no improvement. TR: Poor weights on tracks 2-6, 23-33; weights at 50% for entire observation. Baselines exhibit no fringing at times due to bad IFs. IF 2 has low power and no fringes; slightly nonlinear phase dependence in other IFs. Lowered power in bandpasses in IFs 3,4,7 & 8 and a steep slope in IF 6 at ~21:24. IFs 1,2,7 & 8 are intermittently missing. MC: In search at 00:35-00:39; weights are 0%. Broad RFI spikes in IFs 5-8 during most of observation. JB: RFI spikes in IFs 5-8 during most of observation. Baselines have lowered power in IFs 5 & 6. NT: No fringing in IF 6 around 2:40 due to RFI. Slightly nonlinear phase dependence in all IFs. Major RFI spike in IF 6 at 2:40. WB: RFI in IFs 5&6 at 21:24. ON: Sloping bandpasses in IFs 4 & 8. IFs 1 & 2 missing at 2:43. From analysts@aoc.nrao.eduMon Aug 10 09:15:01 1998 Date: Wed, 08 Jul 1998 10:38:41 -0600 (MDT) From: Data Analysts To: jive@RZMWS0.NFRA.NL Subject: GP020.980608 feedback Dear PI, We have examined the data for project GP020 on 08 Jun. 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to NT for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: TR: Poor tracks 2-6 & 26-32 throughout project. Channel 1 usually has zero weights; weights on channel 4 are usually vairable. IF#4: Fringes are usually weak or absent. Spikes in midband, all IFs. IF#2: bandpass edge problem, lower edge of IF. WB: Bandpass: Sliding off the edge of the bandpass at 1614MHz (pass 2) For pass 2, lower portions of IFs 1 & 2 display no fringing, and an odd bandpass shape. For pass 1, the tape was in search from 01:32 to 01:36. Slight bandpass edge problems, lower edges of IFs of pass 1. CM: Bandpass: Sliding off the edge of the bandpass at 1614MHz (pass 2) Pass 2: IF#1: increasing phase wind of lower portion of IF#1; probably related to passband of the microwave link. Tape in search (both passes) 2:20-2:43 & 4:02 to 4:48: vacuum loss at site. Also, variable playback 3:10-3:19. Bandpass comments: slope, ripple. MC: Poor playback on all tracks intermittently, and for brief periods of time. Bandpass: Slope, bump Sliding off the edge of the bandpass at 1614MHz (pass 2) (IFs 1-2 of pass 2 have low amplitudes) NT: Excellent playback. Some slight bandpass edge problems for IF#2 of pass 1, lower edge; and lower edges of IFs 2,3,4 of pass 2. IF#2 of pass 2: low power and poor fringing after ~12:00 UT. JB: Excellent playback. Pass 1: Big spike in IF 1. No fringing in IF #3 (1618.61 MHz) IF #4 has low amplitude, but fringes seem okay. EF: Excellent playback. Pass 1: Some slight bandpass edge problems, lower edges. ON: Pass 2: Dead track 21, 1:43-1:49. Additional RFI comments: Pass 2: RFI spikes in autocorrelation plots in IFs 1-2 @ 10:19 & 11:36. Pass 2: RFI spikes in autocorrelation plots in IF 2 at: TR, after ~5:00 UT; EF IFs 1-2, after 9:15 UT, JB #2, @ 10:30 UT From analysts@aoc.nrao.eduMon Aug 10 09:15:18 1998 Date: Fri, 10 Jul 1998 09:47:29 -0600 (MDT) From: Data Analysts To: jive@RZMWS0.NFRA.NL Subject: GY001.980606 feedback Dear PI, We have examined the data for project GY001 on 06 Jun. 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all srcs. 4. Cross-correlation bandpass plots were generated for all baselines to MC for scans on all srcs. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: EF: IF#4: RFI, lower part of IF, ~6:15-~12:30 Perfect playback JB: Problems loading tape at site, 4:00-5:37. Tape in search 11:45-11:53 IF#4: low power level & strong RFI throught experiment. Cross-correlated power is also low in IF#4 WB: Perfect playback ON: Slightly variable playback (chnls 2 & 4), 7:07-10:12 No fringing on IF#4 MC: Tape in search 11:45-11:51 A a broad line is present near the bottom of all four IFs. Might this be OH and therefore be expected? NT: Perfect playback SH: Tracks 26,28,30,32 dead during 07:07-10:12; IFs 3&4 dead during this time range. On cross-corr. plots, SH appears weak on 3C84--possibly due to source structure TR: did not observe; recorder problems at site. From vlbiobs@aoc.nrao.eduMon Aug 10 09:17:46 1998 Date: Tue, 14 Jul 1998 11:34:51 -0600 (MDT) From: VLBI Observers To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, fghigo@aoc.nrao.edu, foley@NFRA.NL, jive@RZMWS0.NFRA.NL, kb@astro.uni.torun.pl, kenta@vsop.isas.ac.jp, p062gra@mpifr-bonn.mpg.de, rap@sgra.jpl.nasa.gov, support@dots.jpl.nasa.gov, trigilio@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, vsog@vsop.isas.ac.jp, xhuang@center.shao.ac.cn Subject: V030W PI letter Dear PI, We have examined the data for project V030W on 29 May 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on . 4. Cross-correlation bandpass plots were generated for all baselines to EB,TZ for scans on . 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: Comments on individual stations, note that times stated are approximate. ------------------------------------------------------------------------ EB-looks fine GB-high rate -occasionally does not fringe for a few minutes at 2:05; 4:35 and 5:20 JB-pcals very strong, and occasionally varying in strength across band -high rate MC-high rate NT-possible weak rfi ON-looks fine SH-playback atrocious. If parameter WTTHRESH in task FITLD is set greater than 0.5 most of SH data will not be read in. -Second IF gone (which explains, in part, the low weights) -fringes in first IF look fine TR-recorded wrong polarization; so not correlated TZ-weak fringes UD-high rate -fails to fringe after 1:30; probably due to delay drifting out of sniffer window. If this is true then it should be fine in AIPS. WB-playback a bit ratty for the first couple hours of experiment Space VLBI ---------- There are less than 2 hours of spacecraft tracking, luckily it looks like these 2 hours are good. TZ started 1.5 hours late because the wrong command was sent to the spacecraft and RZ failed due to a problem at the tracking station. . From vlbiobs@aoc.nrao.eduMon Aug 10 09:17:54 1998 Date: Wed, 15 Jul 1998 16:16:07 -0600 (MDT) From: VLBI Observers To: rap@sgra.jpl.nasa.gov Cc: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@NFRA.NL, jive@RZMWS0.NFRA.NL, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, support@dots.jpl.nasa.gov, trigilio@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, vsog@vsop.isas.ac.jp, xhuang@center.shao.ac.cn Subject: V030T PI letter Dear PI, We have examined the data for project V030T on 31 May 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on . 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on . 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: EB-looks fine JB-some low weights on every other pair of forward and reverse passes; looks like this is caused by poor even tracks -pcals strong and variable across band -high rate MC-looks fine NT-looks fine ON-did not observe SH-playback atrocious; if WTTHRESH in FITLD is set greater than 0.5 then all of SH data will be lost; tracks 28-33 dead all of the time, sometimes track 27 goes out, weak on most other tracks -second IF missing -fringes in first IF look great TR-recorded RCP so not correlated TZ-fringes WB-some ratty weights, poor on tracks 31 and 33 -pcals variable across band GZ-weak fringes GB-looks fine RZ-fringes Please see the EVN Experiment Feedback facility at http://www.nfra.nl/jive/evn/session/may98/v030t.hdr for comments from stations on minor problems during observation. Discontinuities in the fringe signal on baselines to the Halca orbiter occur at each handoff from one tracking station to another, and at any dropouts in the phase-transfer link that occur during a tracking pass. Fringe fits should be broken at each such discontinuity to avoid de- correlation. This will happen automatically at handoffs because the tracking-station name assigned to Halca changes, but at link dropouts it is necessary to force an AIPS scan break by passing the following table to AIPS task INDXR via the INFILE adverb. SUBARRAY = 1 / 151 17:17:50.5 ! stn_id = TZ *! 151 20:55:47.6 ! stn_id = GZ *! 152 00:35:12.2 ! stn_id = RZ *! 152 02:26:23.2 ! stn_id = RZ *! / From vlbiobs@aoc.nrao.eduMon Aug 10 09:20:14 1998 Date: Fri, 07 Aug 1998 11:10:53 -0600 (MDT) From: VLBI Observers To: jive@RZMWS0.NFRA.NL Subject: GG036.980607 feedback Dear PI, We have examined the data for project GG036 on 07 Jun. 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on 4C39.25,OQ208,J1219+4829,J1048+7143,J1223+4611. 4. Cross-correlation bandpass plots were generated for all baselines to MC for scans on 4C39.25,OQ208,J1219+4829,J1048+7143,J1223+4611. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: Some RFI spikes appear in autocorrelation plots in the Following IFs: CM2, CM8, JB 1,2,6,7,8, TR2, TR 4(near lower edge), RO 7-8, MC 7-8(intermittent) CM: vacuum loss at site 21:18-23:18 Odd bandpass shapes (narrow microwave passband). EB: Excellent playback. Late on source a few times. JB: Excellent playback. IF 7 low power (though cross-correlation plots appear fine) MC: Excellent playback. Strong pcals. NT: Excellent playback. ON: Track 24 poor 15:50-15:55. Tape in STALL 20:00-20:50. (related to comment on feedback web page concerning SNAP files?) RO: dead track 15, 13:42-14:06. IF #6 dead at this time. Never found any fringes on any source at any timerange, with wide-window searching. No one at JPL claims to find anything wrong at the antenna. TR: First tape: Tracks 2-4 dead, track 5 dead or poor, tracks 6-10 poor. Tape intermittently in search 13:50-14:10 & 14:31-15:00. Tape in STALL 17:11-19:00 (problems at site) IFs 1 & 5 usually dead. Second tape: Poor on all tracks, wts ~0.2-0.4, sometimes a bit higher. No recording at site 19:35 - 20:26. Several IFs at a time missing on second tape. TR#4 & 5 noisy in cross-correlation plots. WB: Tape in search 13:15-13:40. Intermittently in search 13:40-15:00. Variable playback 19:35-20:05. Slightly variable playback 00:05-00:31 IFs 2,4,6,8: strong pcals From analysts@aoc.nrao.eduWed Aug 12 08:50:53 1998 Date: Mon, 10 Aug 1998 09:26:06 -0600 (MDT) From: Data Analysts To: jive@RZMWS0.NFRA.NL Subject: GB027A.980601.sniff Dear PI, We have examined the data for project GB027A on 01 Jun. 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on 0954+658, J0319+41, J0555+39, J0927+39. 4. Cross-correlation bandpass plots were generated for all baselines to NL for scans on 0954+658, J0319+41, J0555+39, J0927+39. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: BR: okay FD: okay HN: Antenna not pointed 1542-1545, 2030-2035, 2200-2330 KP: okay LA: okay MK: Poor tracks 3 & 31 2130-2320 (wts 0.75-0.95) NL: okay OV: okay PT: okay SC: Slightly variable wts on first tape Y27: Poor tracks 31-33 from 2045-2110 & 2130-2200 (wts ~0.5) Tape in search 1400-1430 EB: Due to p.i. error, schedule off by 50 seconds. Frequently late on source or missing scans. Fringes seem to fade after ~1930 UT. MC: Perfect playback. NT: Poor track 21 2115-2200 (wts ~0.6) Track 4 weak 2345-0000UT (wts ~0.95-1.00). ON: Good playback Michale Rupen is keeping the data tapes. From analysts@aoc.nrao.eduThu Aug 27 08:34:38 1998 Date: Mon, 10 Aug 1998 09:26:06 -0600 (MDT) From: Data Analysts To: jive@RZMWS0.NFRA.NL Subject: GB027A.980601.sniff Dear PI, We have examined the data for project GB027A on 01 Jun. 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on 0954+658, J0319+41, J0555+39, J0927+39. 4. Cross-correlation bandpass plots were generated for all baselines to NL for scans on 0954+658, J0319+41, J0555+39, J0927+39. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: BR: okay FD: okay HN: Antenna not pointed 1542-1545, 2030-2035, 2200-2330 KP: okay LA: okay MK: Poor tracks 3 & 31 2130-2320 (wts 0.75-0.95) NL: okay OV: okay PT: okay SC: Slightly variable wts on first tape Y27: Poor tracks 31-33 from 2045-2110 & 2130-2200 (wts ~0.5) Tape in search 1400-1430 EB: Due to p.i. error, schedule off by 50 seconds. Frequently late on source or missing scans. Fringes seem to fade after ~1930 UT. MC: Perfect playback. NT: Poor track 21 2115-2200 (wts ~0.6) Track 4 weak 2345-0000UT (wts ~0.95-1.00). ON: Good playback Michale Rupen is keeping the data tapes. From analysts@aoc.nrao.eduThu Aug 27 08:35:18 1998 Date: Mon, 10 Aug 1998 09:26:44 -0600 (MDT) From: Data Analysts To: p062gra@mpifr-bonn.mpg.de Cc: jive@RZMWS0.NFRA.NL Subject: GB027B.980602 feedback Dear PI, We have examined the data for project GB027B on 02 Jun. 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on OQ208,0954+658,M81. 4. Cross-correlation bandpass plots were generated for all baselines to FD for scans on OQ208,0954+658,M81. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: BR: okay FD: okay HN: antenna autostowed 0404-0419 KP: Tape in STALL 2200-2246. Antenna stowed 0508-0515 LA: Tape in STALL 0310-0316. MK: okay NL: No tape written 2244-2255; see obs. log OV: Tape in search 0005-0007. PT: Antenna stowed 2312-2317 SC: Variable weights, poor on all tracks 1930-1955 Y27: Variable playback for the first few minutes of the last four reverse passes. Slightly increasing phase wind on IFs 7-8. EB: Due to p.i. error, schedule off by 50 seconds. Frequently late on source or missing scans. RO: Never found any fringes, despite intensive wide-window fringe searching. Excelent playback, though. MC: Excellent playback. During fringe searching, amplitudes seemed very low. On a hunch, we switched L & R to see if the polarizations were swapped at the site. They were. Only then did we receive notice that this was the case; we had no indication or warning from anybody at MC to expect this. In the future, it is imperative that when problems like this occur, that the correlator be notified immediately (i.e., via direct email or via the EVN feedback web page) to prevent lots of guessing & wasted correlator time. At any rate, we correlated with the polarizations swapped again, so the amplitudes are now fully recovered. Fringes are a bit weak 2030-2330, though. Intermittent RFI spikes appear in autocorrelation in IF 4 at LA,NL,SC. From vlbiobs@aoc.nrao.eduThu Aug 27 08:36:03 1998 Date: Fri, 07 Aug 1998 11:10:53 -0600 (MDT) From: VLBI Observers To: jive@RZMWS0.NFRA.NL Subject: GG036.980607 feedback Dear PI, We have examined the data for project GG036 on 07 Jun. 1998. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on 4C39.25,OQ208,J1219+4829,J1048+7143,J1223+4611. 4. Cross-correlation bandpass plots were generated for all baselines to MC for scans on 4C39.25,OQ208,J1219+4829,J1048+7143,J1223+4611. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: Some RFI spikes appear in autocorrelation plots in the Following IFs: CM2, CM8, JB 1,2,6,7,8, TR2, TR 4(near lower edge), RO 7-8, MC 7-8(intermittent) CM: vacuum loss at site 21:18-23:18 Odd bandpass shapes (narrow microwave passband). EB: Excellent playback. Late on source a few times. JB: Excellent playback. IF 7 low power (though cross-correlation plots appear fine) MC: Excellent playback. Strong pcals. NT: Excellent playback. ON: Track 24 poor 15:50-15:55. Tape in STALL 20:00-20:50. (related to comment on feedback web page concerning SNAP files?) RO: dead track 15, 13:42-14:06. IF #6 dead at this time. Never found any fringes on any source at any timerange, with wide-window searching. No one at JPL claims to find anything wrong at the antenna. TR: First tape: Tracks 2-4 dead, track 5 dead or poor, tracks 6-10 poor. Tape intermittently in search 13:50-14:10 & 14:31-15:00. Tape in STALL 17:11-19:00 (problems at site) IFs 1 & 5 usually dead. Second tape: Poor on all tracks, wts ~0.2-0.4, sometimes a bit higher. No recording at site 19:35 - 20:26. Several IFs at a time missing on second tape. TR#4 & 5 noisy in cross-correlation plots. WB: Tape in search 13:15-13:40. Intermittently in search 13:40-15:00. Variable playback 19:35-20:05. Slightly variable playback 00:05-00:31 IFs 2,4,6,8: strong pcals