COVER INFORMATION Station: VLBA_BR (Code Br ) Experiment: bb191c, 6cm HSA, Barvainis, Ulvestad et al. Exp. Code: bb191c Schedule Version: 1.00 Processed by SCHED version: 6.02 July 2005 PI: J.S. Ulvestad Address: NRAO, P.O. Box O Socorro, NM 87801 USA Phone: +1-505-835-7300 EMAIL: julvesta@nrao.edu Fax: +1-505-835-7320 Phone during observation: +1-505-835-7300 Observing mode: 256-8-2 Notes: HSA with Eb,Ar,GBT,Y27, 256 Mbps allocated Scheduled in 22-minute blocks for Ar and Eb Ar has long azimuth slew near transit Schedule for VLBA_BR (Code Br ) Page 2 bb191c, 6cm HSA, Barvainis, Ulvestad et al. UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Mon 30 Jan 2006 Day 30 --- Next scan frequencies: 4971.49 4971.49 4979.49 4979.49 4987.49 4987.49 4995.49 4995.49 Next BBC frequencies: 871.49 871.49 879.49 879.49 887.49 887.49 895.49 895.49 Next scan bandwidths: 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 07 45 00 J1224+2122 08 23 54 35.4 97.1 -4.0 -45.3 0 1 1 0 07 45 00 07 47 00 =1222+216 08 25 54 35.7 97.5 -4.0 -45.3 120 F 1 1600 07 45 08 07 47 00 J1225+2235 08 25 54 36.4 96.3 -4.0 -45.9 -7 1 1 1600 07 47 00 07 48 50 --- 08 27 45 36.8 96.7 -4.0 -45.9 103 F 1 3067 07 47 00 07 48 50 J1224+2122 08 27 45 36.0 97.8 -4.0 -45.2 -7 1 1 3067 07 48 50 07 50 00 =1222+216 08 28 55 36.2 98.1 -3.9 -45.2 63 F 1 4000 07 48 50 07 50 00 J1225+2235 08 28 55 36.9 96.9 -3.9 -45.8 -7 1 1 4000 07 50 00 07 51 50 --- 08 30 45 37.2 97.3 -3.9 -45.8 103 F 1 5467 07 50 00 07 51 50 J1224+2122 08 30 45 36.5 98.5 -3.9 -45.1 -7 1 1 5467 07 51 50 07 53 00 =1222+216 08 31 55 36.7 98.7 -3.9 -45.1 63 F 1 6400 07 51 50 07 53 00 J1225+2235 08 31 55 37.4 97.5 -3.9 -45.8 -7 1 1 6400 07 53 00 07 54 50 --- 08 33 46 37.7 97.9 -3.9 -45.7 103 F 1 7867 07 53 00 07 54 50 J1224+2122 08 33 46 37.0 99.1 -3.9 -45.0 -7 1 1 7867 07 54 50 07 56 00 =1222+216 08 34 56 37.2 99.3 -3.8 -45.0 63 F 1 8800 07 54 50 07 56 00 J1225+2235 08 34 56 37.9 98.1 -3.8 -45.7 -7 1 1 8800 07 56 00 07 57 50 --- 08 36 46 38.2 98.5 -3.8 -45.6 103 F 1 10267 07 56 00 07 57 50 J1224+2122 08 36 46 37.5 99.7 -3.8 -44.9 -7 1 1 10267 07 57 50 07 59 00 =1222+216 08 37 56 37.7 99.9 -3.8 -44.9 63 F 1 11200 07 57 50 07 59 00 J1225+2235 08 37 56 38.4 98.7 -3.8 -45.6 -7 1 1 11200 07 59 00 08 00 50 --- 08 39 47 38.7 99.1 -3.8 -45.5 103 F 1 12667 07 59 00 08 00 50 J1224+2122 08 39 47 38.0 100.3 -3.8 -44.8 -7 1 1 12667 08 00 50 08 02 00 =1222+216 08 40 57 38.2 100.6 -3.7 -44.8 63 F 1 13600 08 00 50 08 02 00 J1225+2235 08 40 57 38.9 99.4 -3.7 -45.5 -7 1 1 13600 08 02 00 08 03 50 --- 08 42 47 39.2 99.7 -3.7 -45.4 103 F 1 15067 08 02 00 Schedule for VLBA_BR (Code Br ) Page 3 bb191c, 6cm HSA, Barvainis, Ulvestad et al. UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Mon 30 Jan 2006 Day 30 --- 08 03 50 J1224+2122 08 42 47 38.5 101.0 -3.7 -44.7 -7 1 1 15067 08 03 50 08 05 00 =1222+216 08 43 57 38.7 101.2 -3.7 -44.7 63 F 1 16000 08 03 50 08 05 00 J1225+2235 08 43 57 39.4 100.0 -3.7 -45.4 -7 1 1 16000 08 05 00 08 07 00 --- 08 45 58 39.8 100.4 -3.7 -45.3 113 F 1 17600 08 05 00 08 08 00 J1224+2122 08 46 58 39.2 101.8 -3.6 -44.5 53 1 2 17600 08 08 00 08 09 00 =1222+216 08 47 58 39.3 102.1 -3.6 -44.5 60 R 1 16800 08 08 08 08 09 00 J1225+2235 08 47 58 40.1 100.8 -3.6 -45.2 -8 1 2 16800 08 09 00 08 11 00 --- 08 49 58 40.4 101.3 -3.6 -45.1 112 R 1 15200 08 09 00 08 11 00 J1224+2122 08 49 58 39.6 102.5 -3.6 -44.4 -8 1 2 15200 08 11 00 08 12 20 =1222+216 08 51 19 39.9 102.8 -3.6 -44.3 72 R 1 14133 08 11 00 08 15 20 J1310+3220 08 54 19 40.1 83.8 -4.3 -51.7 161 1 2 14133 08 15 20 08 22 00 =1308+326 09 01 00 41.2 85.0 -4.2 -51.9 400 R 1 8800 08 15 28 08 24 00 J1224+2122 09 03 01 41.8 105.4 -3.4 -43.7 100 1 2 8800 08 24 00 08 26 30 =1222+216 09 05 31 42.2 105.9 -3.3 -43.6 150 R 1 6800 08 24 08 08 26 30 J1225+2235 09 05 31 42.9 104.7 -3.3 -44.4 -8 1 2 6800 08 26 30 08 28 40 --- 09 07 41 43.3 105.2 -3.3 -44.2 122 R 1 5067 08 26 30 08 28 40 J1224+2122 09 07 41 42.5 106.4 -3.3 -43.4 -8 1 2 5067 08 28 40 08 29 50 =1222+216 09 08 52 42.7 106.7 -3.3 -43.3 62 R 1 4133 08 28 40 08 29 50 J1225+2235 09 08 52 43.5 105.4 -3.3 -44.2 -8 1 2 4133 08 29 50 08 31 50 --- 09 10 52 43.8 105.9 -3.2 -44.0 112 R 1 2533 08 29 50 08 31 50 J1224+2122 09 10 52 43.0 107.2 -3.2 -43.2 -8 1 2 2533 08 31 50 08 33 00 =1222+216 09 12 02 43.2 107.4 -3.2 -43.1 62 R 1 1600 08 31 50 08 33 00 J1225+2235 09 12 02 44.0 106.2 -3.2 -44.0 -8 1 2 1600 08 33 00 08 35 00 --- 09 14 02 44.3 106.6 -3.2 -43.8 112 R 1 0 08 33 00 08 36 00 J1224+2122 09 15 03 43.7 108.1 -3.2 -42.9 53 1 3 0 08 36 00 08 37 10 =1222+216 09 16 13 43.9 108.4 -3.2 -42.8 70 F 1 933 08 36 08 08 37 10 J1225+2235 09 16 13 44.7 107.1 -3.2 -43.7 -8 1 3 933 08 37 10 08 39 30 --- 09 18 33 45.0 107.7 -3.1 -43.5 132 F 1 2800 08 37 10 Schedule for VLBA_BR (Code Br ) Page 4 bb191c, 6cm HSA, Barvainis, Ulvestad et al. UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Mon 30 Jan 2006 Day 30 --- 08 39 30 J1224+2122 09 18 33 44.2 109.0 -3.1 -42.7 -8 1 3 2800 08 39 30 08 40 40 =1222+216 09 19 43 44.4 109.3 -3.1 -42.6 62 F 1 3733 08 39 30 08 40 40 J1225+2235 09 19 43 45.2 108.0 -3.1 -43.4 -8 1 3 3733 08 40 40 08 43 00 --- 09 22 04 45.6 108.5 -3.1 -43.3 132 F 1 5600 08 40 40 08 43 00 J1224+2122 09 22 04 44.8 109.8 -3.1 -42.4 -8 1 3 5600 08 43 00 08 44 10 =1222+216 09 23 14 45.0 110.1 -3.0 -42.3 62 F 1 6533 08 43 00 08 44 10 J1225+2235 09 23 14 45.8 108.8 -3.0 -43.2 -8 1 3 6533 08 44 10 08 46 30 --- 09 25 34 46.1 109.4 -3.0 -43.0 132 F 1 8400 08 44 10 08 46 30 J1224+2122 09 25 34 45.3 110.7 -3.0 -42.1 -8 1 3 8400 08 46 30 08 47 40 =1222+216 09 26 44 45.5 111.0 -3.0 -42.0 62 F 1 9333 08 46 30 08 47 40 J1225+2235 09 26 44 46.3 109.7 -3.0 -42.9 -8 1 3 9333 08 47 40 08 50 00 --- 09 29 05 46.7 110.2 -2.9 -42.7 132 F 1 11200 08 47 40 08 50 00 J1224+2122 09 29 05 45.9 111.6 -2.9 -41.8 -8 1 3 11200 08 50 00 08 51 10 =1222+216 09 30 15 46.1 111.8 -2.9 -41.7 62 F 1 12133 08 50 00 08 51 10 J1225+2235 09 30 15 46.9 110.5 -2.9 -42.6 -8 1 3 12133 08 51 10 08 53 30 --- 09 32 35 47.2 111.1 -2.9 -42.4 132 F 1 14000 08 51 10 08 53 30 J1224+2122 09 32 35 46.4 112.4 -2.9 -41.5 -8 1 3 14000 08 53 30 08 54 40 =1222+216 09 33 46 46.6 112.7 -2.9 -41.4 62 F 1 14933 08 53 30 08 54 40 J1225+2235 09 33 46 47.4 111.4 -2.9 -42.3 -8 1 3 14933 08 54 40 08 57 00 --- 09 36 06 47.8 112.0 -2.8 -42.1 132 F 1 16800 08 54 40 08 57 00 J1224+2122 09 36 06 47.0 113.3 -2.8 -41.1 -8 1 3 16800 08 57 00 08 58 00 =1222+216 09 37 06 47.1 113.6 -2.8 -41.0 52 F 1 17600 08 57 00 08 59 00 J1225+2235 09 38 06 48.1 112.5 -2.8 -41.9 52 1 4 17600 08 59 00 09 01 00 --- 09 40 07 48.4 113.0 -2.8 -41.7 120 R 1 16000 08 59 08 09 01 00 J1224+2122 09 40 07 47.6 114.4 -2.8 -40.7 -8 1 4 16000 09 01 00 09 02 10 =1222+216 09 41 17 47.8 114.7 -2.7 -40.6 62 R 1 15067 09 01 00 09 02 10 J1225+2235 09 41 17 48.6 113.3 -2.7 -41.6 -8 1 4 15067 09 02 10 09 04 10 --- 09 43 17 48.9 113.9 -2.7 -41.4 112 R 1 13467 09 02 10 Schedule for VLBA_BR (Code Br ) Page 5 bb191c, 6cm HSA, Barvainis, Ulvestad et al. UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Mon 30 Jan 2006 Day 30 --- 09 04 10 J1224+2122 09 43 17 48.1 115.2 -2.7 -40.4 -8 1 4 13467 09 04 10 09 05 20 =1222+216 09 44 27 48.2 115.5 -2.7 -40.3 62 R 1 12533 09 04 10 09 05 20 J1225+2235 09 44 27 49.1 114.2 -2.7 -41.2 -8 1 4 12533 09 05 20 09 07 20 --- 09 46 28 49.4 114.7 -2.7 -41.0 112 R 1 10933 09 05 20 09 07 20 J1224+2122 09 46 28 48.5 116.1 -2.6 -40.1 -8 1 4 10933 09 07 20 09 08 30 =1222+216 09 47 38 48.7 116.4 -2.6 -39.9 62 R 1 10000 09 07 20 09 08 30 J1225+2235 09 47 38 49.5 115.0 -2.6 -40.9 -8 1 4 10000 09 08 30 09 10 30 --- 09 49 38 49.9 115.6 -2.6 -40.7 112 R 1 8400 09 08 30 09 10 30 J1224+2122 09 49 38 49.0 116.9 -2.6 -39.7 -8 1 4 8400 09 10 30 09 11 40 =1222+216 09 50 48 49.2 117.2 -2.6 -39.6 62 R 1 7467 09 10 30 09 11 40 J1212+1925 09 50 48 49.4 122.5 -2.4 -36.7 -9 1 4 7467 09 11 40 09 13 40 =1210+197 09 52 49 49.7 123.0 -2.3 -36.4 111 R 1 5867 09 11 40 09 13 40 J1224+2122 09 52 49 49.5 117.8 -2.5 -39.3 -10 1 4 5867 09 13 40 09 14 50 =1222+216 09 53 59 49.7 118.1 -2.5 -39.2 60 R 1 4933 09 13 40 09 14 50 J1225+2235 09 53 59 50.5 116.8 -2.5 -40.2 -8 1 4 4933 09 14 50 09 16 50 --- 09 55 59 50.8 117.3 -2.5 -39.9 112 R 1 3333 09 14 50 09 16 50 J1224+2122 09 55 59 49.9 118.7 -2.5 -39.0 -8 1 4 3333 09 16 50 09 18 00 =1222+216 09 57 09 50.1 119.0 -2.5 -38.8 62 R 1 2400 09 16 50 09 18 00 J1225+2235 09 57 09 51.0 117.6 -2.5 -39.8 -8 1 4 2400 09 18 00 09 20 00 --- 09 59 10 51.3 118.2 -2.4 -39.6 112 R 1 800 09 18 00 09 20 00 J1224+2122 09 59 10 50.4 119.6 -2.4 -38.6 -8 1 4 800 09 20 00 09 21 00 =1222+216 10 00 10 50.6 119.9 -2.4 -38.4 52 R 1 0 09 20 00 09 22 00 J1225+2235 10 01 10 51.6 118.8 -2.4 -39.3 52 1 5 0 09 22 00 09 24 00 --- 10 03 10 51.9 119.4 -2.4 -39.0 120 F 1 1600 09 22 08 09 24 00 J1224+2122 10 03 10 51.0 120.7 -2.4 -38.0 -8 1 5 1600 09 24 00 09 25 10 =1222+216 10 04 21 51.2 121.1 -2.3 -37.9 62 F 1 2533 09 24 00 09 25 10 J1225+2235 10 04 21 52.0 119.7 -2.4 -38.9 -8 1 5 2533 09 25 10 09 27 20 --- 10 06 31 52.3 120.3 -2.3 -38.6 122 F 1 4267 09 25 10 Schedule for VLBA_BR (Code Br ) Page 6 bb191c, 6cm HSA, Barvainis, Ulvestad et al. UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. Automatic tape allocation specified. Tape positions are just estimates. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) SYNC ---------------------------------------------------------------------------------------- --- Mon 30 Jan 2006 Day 30 --- 09 27 20 J1224+2122 10 06 31 51.5 121.7 -2.3 -37.6 -8 1 5 4267 09 27 20 09 28 30 =1222+216 10 07 41 51.6 122.1 -2.3 -37.4 62 F 1 5200 09 27 20 09 28 30 J1225+2235 10 07 41 52.5 120.7 -2.3 -38.4 -8 1 5 5200 09 28 30 09 30 40 --- 10 09 52 52.8 121.3 -2.3 -38.1 122 F 1 6933 09 28 30 09 30 40 J1224+2122 10 09 52 51.9 122.7 -2.3 -37.1 -8 1 5 6933 09 30 40 09 31 50 =1222+216 10 11 02 52.1 123.1 -2.2 -36.9 62 F 1 7867 09 30 40 09 31 50 J1225+2235 10 11 02 53.0 121.7 -2.2 -37.9 -8 1 5 7867 09 31 50 09 34 00 --- 10 13 12 53.3 122.4 -2.2 -37.6 122 F 1 9600 09 31 50 09 34 00 J1224+2122 10 13 12 52.4 123.7 -2.2 -36.6 -8 1 5 9600 09 34 00 09 35 10 =1222+216 10 14 22 52.6 124.1 -2.2 -36.4 62 F 1 10533 09 34 00 09 35 10 J1225+2235 10 14 22 53.5 122.7 -2.2 -37.4 -8 1 5 10533 09 35 10 09 37 20 --- 10 16 33 53.8 123.4 -2.2 -37.1 122 F 1 12267 09 35 10 09 37 20 J1224+2122 10 16 33 52.9 124.8 -2.1 -36.1 -8 1 5 12267 09 37 20 09 38 20 =1222+216 10 17 33 53.0 125.1 -2.1 -35.9 52 F 1 13067 09 37 20 09 40 20 J1310+3220 10 19 33 54.3 100.4 -2.9 -51.0 98 1 5 13067 09 40 20 09 45 00 =1308+326 10 24 14 55.0 101.4 -2.8 -50.7 280 F 1 16800 09 40 28 SETUP FILE INFORMATION: NOTE: If DOPPLER, FREQ, or BW were used, see the individual scans for the final BBC settings. Setup file: /users/cwalker/sched/setups/v6cm-256-8-2.set Matches group v6cm_2 in /home/arana/cwalker/sched/catalogs/freq.dat Setup group: 13 Station: VLBA_BR Total bit rate: 256 Format: VLBA1:2 Bits per sample: 2 Sample rate: 16.000 Number of channels: 8 Passes/head pos: 1 Speedup factor: 1.00 Tape used at high density at 160.000 ips. Time per pass is 22.00 minutes. 1st LO= 4100.00 4100.00 4100.00 4100.00 4100.00 4100.00 4100.00 4100.00 Net SB= U U U U U U U U Pol. = RCP LCP RCP LCP RCP LCP RCP LCP BBC = 1 2 3 4 5 6 7 8 BBC SB= U U U U U U U U IF = A C A C A C A C VLBA FE= 6cm omit 6cm omit VLBA Synth= 15.4 4.1 15.4 The following frequency sets based on this setup were used. Frequency Set: 13 Setup file default. Used pcal sets: 1 LO sum= 4971.49 4971.49 4979.49 4979.49 4987.49 4987.49 4995.49 4995.49 BBC fr= 871.49 871.49 879.49 879.49 887.49 887.49 895.49 895.49 Bandwd= 8.000 8.000 8.000 8.000 8.000 8.000 8.000 8.000 The following pulse cal sets were used with this setup: Pulse cal detection set: 1 PCAL = 1MHZ PCALXB1= S1 S3 S5 S7 S1 S3 S5 S7 PCALXB2= S2 S4 S6 S8 S2 S4 S6 S8 PCALFR1= 510 510 510 510 6510 6510 6510 6510 PCALFR2= 510 510 510 510 6510 6510 6510 6510 Track assignments are: track1= 2, 10, 18, 26, 3, 11, 19, 27 barrel=roll_auto SOURCE LIST -- bb191c, 6cm HSA, Barvainis, Ulvestad et al. Catalog positions marked with *. Precession of date coordinates is based on stop time of first scan. Names used in schedule marked with *. Short names used in VLA and SNAP files marked with +. Observation date used in B1950/J2000 coordinate conversion (PRECDATE): 1979.900 No adjustments are made for rates (DRA, DDEC). Scan hours are for recording scans only. Baseline hours are only counted for scans above horizon at both ends. Source Source position (RA/Dec) Error (B1950) (J2000) (Date) (mas) * J1225+2235 12 22 56.587068 * 12 25 27.400900 12 25 46.684731 0.00 22 51 49.44291 * 22 35 13.05200 22 32 59.63062 0.00 From catalog imbedded in main SCHED input file. 0.964 scan hours, 76.059 baseline hours above horizon. * J1212+1925 12 10 23.542104 * 12 12 56.095713 12 13 15.605578 2.04 1210+197 19 42 27.70903 * 19 25 47.01652 19 23 34.50202 1.42 /users/cwalker/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.033 scan hours, 2.304 baseline hours above horizon. * J1224+2122 12 22 23.408705 * 12 24 54.458390 12 25 13.754075 0.24 1222+216 21 39 23.03700 * 21 22 46.38861 21 20 33.26090 0.44 J1224+21 /users/cwalker/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.631 scan hours, 44.348 baseline hours above horizon. * J1310+3220 13 08 07.560130 * 13 10 28.663849 13 10 46.668396 0.24 1308+326 32 36 40.23882 * 32 20 43.78289 32 18 30.52179 0.40 J1310+32 /users/cwalker/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.189 scan hours, 16.568 baseline hours above horizon. * J1331+3030 13 28 49.657757 * 13 31 08.288049 13 31 25.816614 0.37 1328+307 30 45 58.64062 * 30 30 32.95926 30 28 22.89086 0.47 3C286 /users/cwalker/sched/catalogs/sources.vlba J1331+30 VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.000 scan hours, 0.000 baseline hours above horizon. The solar corona can cause unstable phases for sources too close to the Sun. SCHED provides warnings at individual scans for distances less than 10 degrees. The distance from the Sun to each source in this schedule is: Source Sun distance (deg) J1225+2235 129.6 J1212+1925 132.2 J1224+2122 129.6 J1310+3220 120.2 J1331+3030 115.7 Barry Clark estimates from predictions by Ketan Desai of IPM scattering sizes that the Sun will cause amplitude reductions on the longest VLBA baselines at a solar distance of 60deg F^(-0.6) where F is in GHz. For common VLBI bands, this is: 327 MHz 117. deg 610 MHz 81. deg 1.6 GHz 45. deg 2.3 GHz 36. deg 5.0 GHz 23. deg 8.4 GHz 17. deg 15.0 GHz 12. deg 22.0 GHz 9. deg 43.0 GHz 6. deg