COVER INFORMATION Station: ZELENCHK (Code Zc ) Experiment: X band NME+FTP-FT Experiment Exp. Code: N13X4 Schedule Version: 1.00 Processed by SCHED version: 10.20 Release of about July 12, 2012 PI: Gabriele SURCIS Address: JIVE Postbus 2 7990 AA Dwingeloo The Netherlands Phone: +31-521-596508 EMAIL: surcis@jive.nl Fax: Phone during observation: +31-521-596508 Observing mode: 512-8-2 Notes: 8 x 16 MHz, 2 bit sampling Check antenna pointing, Please Two FTP-FT scan scheduled. COVER LETTER: This is the schedule for the 3.6 NME and ftp fringe-test on 04 November 2013 involving 12 antennas: Eb Wb On20 Mc Nt Ys Sv Zc Bd Ur Sh Hh (+Md). The schedule consists of long integrations on strong calibrators like J1751+0939 and J1850+2825 as well as phase-referencing parts with a continuum source as target. Two ftp-fringe tests are scheduled throughout the experiment: ~10:40 (scan 2, 2 sec, J1751+0939) ~13:22 (scan 67, 2 sec, J1850+2825) Please make sure that the autoftp is set up correctly. Thanks! Good luck with the session! Gabriele Schedule for ZELENCHK (Code Zc ) Page 2 X band NME+FTP-FT Experiment UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Mon 4 Nov 2013 Day 308 --- Next scan frequencies: 8391.49 8391.49 8391.49 8391.49 8407.49 8407.49 8407.49 8407.49 8423.49 8423.49 8423.49 8423.49 8439.49 8439.49 8439.49 8439.49 Next BBC frequencies: 311.49 311.49 311.49 311.49 327.49 327.49 327.49 327.49 343.49 343.49 343.49 343.49 359.49 359.49 359.49 359.49 Next scan bandwidths: 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 10 30 00 J1751+0939 16 11 35 49.5 499.8 -1.7 -28.2 0 0 10 30 00 10 35 00 =1749+096 16 16 36 50.1 501.5 -1.6 -27.1 300 19 10 30 01 10 36 00 J1751+0939 16 17 36 50.2 501.9 -1.6 -26.9 53 19 10 36 00 10 41 00 =1749+096 16 22 37 50.7 503.6 -1.5 -25.7 300 39 10 36 01 10 42 00 J1751+0939 16 23 37 50.8 504.0 -1.5 -25.5 53 39 10 42 00 10 47 00 =1749+096 16 28 38 51.3 505.8 -1.4 -24.3 300 58 10 42 01 10 49 00 J1925+2106 16 30 38 47.2 467.5 -2.9 -47.6 58 58 10 49 00 10 51 00 =1923+210 16 32 39 47.6 467.9 -2.9 -47.4 120 66 10 49 01 10 51 00 J1925+2106 16 32 39 47.6 467.9 -2.9 -47.4 -5 66 No stop 10 53 00 =1923+210 16 34 39 47.9 468.4 -2.9 -47.3 115 74 10 51 01 10 54 00 J1931+2243 16 35 39 48.2 465.6 -2.9 -48.9 40 74 10 54 00 10 55 30 =1929+226 16 37 10 48.5 465.9 -2.9 -48.8 90 79 10 54 01 10 55 30 J1925+2106 16 37 10 48.3 469.0 -2.8 -47.0 -21 79 No stop 10 57 30 =1923+210 16 39 10 48.7 469.5 -2.8 -46.9 99 87 10 55 31 10 58 30 J1931+2243 16 40 10 49.0 466.6 -2.9 -48.6 39 87 10 58 30 11 00 00 =1929+226 16 41 40 49.3 467.0 -2.8 -48.5 90 93 10 58 31 11 00 00 J1925+2106 16 41 40 49.1 470.1 -2.7 -46.6 -21 93 No stop 11 02 00 =1923+210 16 43 41 49.4 470.6 -2.7 -46.4 99 101 11 00 01 11 03 00 J1931+2243 16 44 41 49.8 467.7 -2.8 -48.2 39 101 11 03 00 11 04 30 =1929+226 16 46 11 50.1 468.0 -2.8 -48.1 90 106 11 03 01 11 04 30 J1925+2106 16 46 11 49.9 471.2 -2.7 -46.2 -21 106 No stop 11 06 30 =1923+210 16 48 11 50.2 471.7 -2.6 -46.0 99 114 11 04 31 11 07 30 J1931+2243 16 49 12 50.6 468.8 -2.7 -47.8 39 114 11 07 30 11 09 00 =1929+226 16 50 42 50.8 469.1 -2.7 -47.7 90 120 11 07 31 11 09 00 J1925+2106 16 50 42 50.6 472.4 -2.6 -45.7 -21 120 No stop 11 11 00 =1923+210 16 52 42 51.0 472.9 -2.6 -45.5 99 128 11 09 01 Schedule for ZELENCHK (Code Zc ) Page 3 X band NME+FTP-FT Experiment UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Mon 4 Nov 2013 Day 308 --- 11 12 00 J1931+2243 16 53 42 51.3 469.9 -2.6 -47.4 39 128 11 12 00 11 13 30 =1929+226 16 55 12 51.6 470.3 -2.6 -47.3 90 134 11 12 01 11 13 30 J1925+2106 16 55 12 51.4 473.5 -2.5 -45.2 -21 134 No stop 11 15 30 =1923+210 16 57 13 51.7 474.1 -2.5 -45.0 99 141 11 13 31 11 16 30 J1931+2243 16 58 13 52.1 471.0 -2.6 -46.9 39 141 11 16 30 11 18 00 =1929+226 16 59 43 52.4 471.4 -2.5 -46.8 90 147 11 16 31 11 18 00 J1925+2106 16 59 43 52.1 474.7 -2.4 -44.7 -21 147 No stop 11 20 00 =1923+210 17 01 44 52.4 475.3 -2.4 -44.4 99 155 11 18 01 11 21 00 J1931+2243 17 02 44 52.9 472.2 -2.5 -46.5 39 155 11 21 00 11 22 30 =1929+226 17 04 14 53.1 472.6 -2.5 -46.3 90 161 11 21 01 11 22 30 J1925+2106 17 04 14 52.9 476.0 -2.4 -44.1 -22 161 No stop 11 24 30 =1923+210 17 06 14 53.2 476.5 -2.3 -43.8 98 168 11 22 31 11 25 30 J1931+2243 17 07 14 53.6 473.4 -2.4 -45.9 39 168 11 25 30 11 27 00 =1929+226 17 08 45 53.9 473.8 -2.4 -45.7 90 174 11 25 31 11 27 00 J1925+2106 17 08 45 53.6 477.2 -2.3 -43.5 -22 174 No stop 11 29 00 =1923+210 17 10 45 53.9 477.8 -2.3 -43.2 98 182 11 27 01 11 30 00 J1931+2243 17 11 45 54.4 474.6 -2.3 -45.4 39 182 11 30 00 11 31 30 =1929+226 17 13 15 54.6 475.1 -2.3 -45.2 90 188 11 30 01 11 31 30 J1925+2106 17 13 15 54.3 478.6 -2.2 -42.8 -22 188 No stop 11 33 30 =1923+210 17 15 16 54.6 479.1 -2.2 -42.5 98 195 11 31 31 11 34 30 J1931+2243 17 16 16 55.1 475.9 -2.3 -44.8 38 195 11 34 30 11 36 00 =1929+226 17 17 46 55.3 476.3 -2.2 -44.6 90 201 11 34 31 11 36 00 J1925+2106 17 17 46 55.0 479.9 -2.1 -42.1 -22 201 No stop 11 38 00 =1923+210 17 19 47 55.3 480.5 -2.1 -41.8 98 209 11 36 01 11 39 00 J1931+2243 17 20 47 55.8 477.2 -2.2 -44.1 38 209 11 39 00 11 40 30 =1929+226 17 22 17 56.1 477.7 -2.2 -43.9 90 215 11 39 01 11 40 30 J1925+2106 17 22 17 55.7 481.3 -2.1 -41.4 -22 215 No stop 11 42 30 =1923+210 17 24 17 56.0 481.9 -2.0 -41.1 98 223 11 40 31 11 43 30 J1931+2243 17 25 17 56.5 478.6 -2.1 -43.4 38 223 11 43 30 11 45 00 =1929+226 17 26 48 56.8 479.0 -2.1 -43.2 90 228 11 43 31 Schedule for ZELENCHK (Code Zc ) Page 4 X band NME+FTP-FT Experiment UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Mon 4 Nov 2013 Day 308 --- 11 45 00 J1925+2106 17 26 48 56.4 482.7 -2.0 -40.6 -22 228 No stop 11 47 00 =1923+210 17 28 48 56.7 483.3 -2.0 -40.3 98 236 11 45 01 11 48 00 J1931+2243 17 29 48 57.2 480.0 -2.0 -42.7 38 236 11 48 00 11 49 30 =1929+226 17 31 18 57.5 480.4 -2.0 -42.5 90 242 11 48 01 11 49 30 J1925+2106 17 31 18 57.1 484.2 -1.9 -39.8 -22 242 No stop 11 51 30 =1923+210 17 33 19 57.4 484.8 -1.9 -39.4 98 250 11 49 31 11 52 30 J1931+2243 17 34 19 57.9 481.4 -2.0 -41.9 38 250 11 52 30 11 54 00 =1929+226 17 35 49 58.2 481.9 -1.9 -41.7 90 255 11 52 31 11 54 00 J1925+2106 17 35 49 57.8 485.7 -1.8 -39.0 -23 255 No stop 11 56 00 =1923+210 17 37 49 58.0 486.4 -1.8 -38.6 97 263 11 54 01 11 57 00 J1931+2243 17 38 50 58.6 482.9 -1.9 -41.1 38 263 11 57 00 11 58 30 =1929+226 17 40 20 58.9 483.4 -1.9 -40.8 90 269 11 57 01 11 58 30 J1925+2106 17 40 20 58.4 487.2 -1.8 -38.0 -23 269 No stop 12 00 30 =1923+210 17 42 20 58.7 487.9 -1.7 -37.6 97 277 11 58 31 12 01 30 J1931+2243 17 43 20 59.3 484.4 -1.8 -40.2 38 277 12 01 30 12 03 00 =1929+226 17 44 51 59.5 484.9 -1.8 -39.9 90 283 12 01 31 12 03 00 J1925+2106 17 44 51 59.1 488.8 -1.7 -37.1 -23 283 No stop 12 05 00 =1923+210 17 46 51 59.3 489.6 -1.7 -36.6 97 290 12 03 01 12 06 00 J1931+2243 17 47 51 60.0 486.0 -1.7 -39.3 38 290 12 06 00 12 07 30 =1929+226 17 49 21 60.2 486.5 -1.7 -39.0 90 296 12 06 01 12 07 30 J1925+2106 17 49 21 59.7 490.5 -1.6 -36.1 -23 296 No stop 12 09 30 =1923+210 17 51 22 60.0 491.2 -1.6 -35.6 97 304 12 07 31 12 10 30 J1931+2243 17 52 22 60.6 487.6 -1.7 -38.3 37 304 12 10 30 12 12 00 =1929+226 17 53 52 60.8 488.2 -1.6 -38.0 90 310 12 10 31 12 12 00 J1925+2106 17 53 52 60.3 492.2 -1.5 -35.0 -23 310 No stop 12 14 00 =1923+210 17 55 52 60.6 493.0 -1.5 -34.5 97 317 12 12 01 12 15 00 J1931+2243 17 56 53 61.3 489.3 -1.6 -37.3 37 317 12 15 00 12 16 30 =1929+226 17 58 23 61.5 489.9 -1.6 -36.9 90 323 12 15 01 12 16 30 J1925+2106 17 58 23 60.9 494.0 -1.5 -33.9 -23 323 No stop 12 18 30 =1923+210 18 00 23 61.1 494.8 -1.4 -33.3 97 331 12 16 31 Schedule for ZELENCHK (Code Zc ) Page 5 X band NME+FTP-FT Experiment UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Mon 4 Nov 2013 Day 308 --- 12 19 30 J1931+2243 18 01 23 61.9 491.1 -1.5 -36.2 37 331 12 19 30 12 21 00 =1929+226 18 02 54 62.1 491.7 -1.5 -35.8 90 337 12 19 31 12 21 00 J1925+2106 18 02 54 61.5 495.8 -1.4 -32.7 -23 337 No stop 12 23 00 =1923+210 18 04 54 61.7 496.6 -1.4 -32.1 97 344 12 21 01 12 24 00 J1931+2243 18 05 54 62.5 492.9 -1.4 -35.0 37 344 12 24 00 12 25 30 =1929+226 18 07 24 62.7 493.5 -1.4 -34.6 90 350 12 24 01 12 25 30 J1925+2106 18 07 24 62.0 497.7 -1.3 -31.4 -24 350 No stop 12 27 30 =1923+210 18 09 25 62.3 498.5 -1.3 -30.8 96 358 12 25 31 12 28 30 J1931+2243 18 10 25 63.1 494.8 -1.4 -33.8 37 358 12 28 30 12 30 00 =1929+226 18 11 55 63.3 495.4 -1.3 -33.3 90 364 12 28 31 12 30 00 J1925+2106 18 11 55 62.6 499.6 -1.2 -30.1 -24 364 No stop 12 32 00 =1923+210 18 13 55 62.8 500.5 -1.2 -29.5 96 372 12 30 01 12 33 00 J1931+2243 18 14 56 63.7 496.7 -1.3 -32.5 37 372 12 33 00 12 34 30 =1929+226 18 16 26 63.8 497.4 -1.3 -32.0 90 377 12 33 01 12 34 30 J1925+2106 18 16 26 63.1 501.6 -1.2 -28.7 -24 377 No stop 12 36 30 =1923+210 18 18 26 63.3 502.5 -1.1 -28.1 96 385 12 34 31 12 37 30 J1931+2243 18 19 26 64.2 498.7 -1.2 -31.1 37 385 12 37 30 12 39 00 =1929+226 18 20 57 64.4 499.4 -1.2 -30.6 90 391 12 37 31 12 39 00 J1925+2106 18 20 57 63.6 503.7 -1.1 -27.3 -24 391 No stop 12 41 00 =1923+210 18 22 57 63.8 504.6 -1.1 -26.6 96 399 12 39 01 12 42 00 J1931+2243 18 23 57 64.7 500.8 -1.1 -29.7 37 399 12 42 00 12 43 30 =1929+226 18 25 27 64.9 501.5 -1.1 -29.2 90 404 12 42 01 12 43 30 J1925+2106 18 25 27 64.0 505.8 -1.0 -25.8 -24 404 No stop 12 45 30 =1923+210 18 27 28 64.2 506.8 -1.0 -25.1 96 412 12 43 31 12 46 30 J1931+2243 18 28 28 65.2 503.0 -1.1 -28.1 37 412 12 46 30 12 48 00 =1929+226 18 29 58 65.4 503.7 -1.0 -27.6 90 418 12 46 31 12 48 00 J1925+2106 18 29 58 64.5 508.0 -0.9 -24.2 -24 418 No stop 12 50 00 =1923+210 18 31 58 64.7 509.0 -0.9 -23.5 96 426 12 48 01 12 51 00 J1931+2243 18 32 59 65.7 505.2 -1.0 -26.6 37 426 12 51 00 12 52 30 =1929+226 18 34 29 65.9 505.9 -1.0 -26.0 90 432 12 51 01 Schedule for ZELENCHK (Code Zc ) Page 6 X band NME+FTP-FT Experiment UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Mon 4 Nov 2013 Day 308 --- 12 52 30 J1925+2106 18 34 29 64.9 510.3 -0.9 -22.6 -24 432 No stop 12 54 30 =1923+210 18 36 29 65.1 511.3 -0.8 -21.8 96 439 12 52 31 12 55 30 J1931+2243 18 37 29 66.2 507.5 -0.9 -24.9 37 439 12 55 30 12 57 00 =1929+226 18 38 59 66.3 508.3 -0.9 -24.3 90 445 12 55 31 12 57 00 J1925+2106 18 38 59 65.3 512.6 -0.8 -20.9 -24 445 No stop 12 59 00 =1923+210 18 41 00 65.5 513.7 -0.8 -20.1 96 453 12 57 01 13 00 00 J1931+2243 18 42 00 66.6 509.9 -0.8 -23.2 37 453 13 00 00 13 01 30 =1929+226 18 43 30 66.7 510.7 -0.8 -22.6 90 459 13 00 01 13 01 30 J1925+2106 18 43 30 65.6 515.0 -0.7 -19.1 -24 459 No stop 13 03 30 =1923+210 18 45 31 65.8 516.1 -0.7 -18.3 96 466 13 01 31 13 04 30 J1931+2243 18 46 31 67.0 512.3 -0.8 -21.3 37 466 13 04 30 13 06 00 =1929+226 18 48 01 67.1 513.1 -0.7 -20.7 90 472 13 04 31 13 07 00 J1925+2106 18 49 01 66.0 518.0 -0.6 -16.9 36 472 13 07 00 13 09 00 =1923+210 18 51 01 66.2 519.1 -0.6 -16.0 120 480 13 07 01 13 11 00 J1850+2825 18 53 02 74.6 541.7 0.0 1.4 74 480 13 11 00 13 17 00 =1848+283 18 59 03 74.6 546.7 0.1 5.5 360 503 13 11 01 13 18 00 J1850+2825 19 00 03 74.5 547.5 0.2 6.1 52 503 13 18 00 13 23 00 =1848+283 19 05 04 74.4 551.6 0.2 9.5 300 523 13 18 01 13 24 00 J1850+2825 19 06 04 74.4 552.4 0.3 10.1 52 523 13 24 00 13 30 00 =1848+283 19 12 05 74.1 557.1 0.4 14.0 360 546 13 24 01 SETUP FILE INFORMATION: NOTE: If DOPPLER, FREQ, or BW were used, see the individual scans for the final BBC settings. ======== Setup file: sess313.X512 Matching groups in /aps3/sched10.2/catalogs/freq.dat: kvzr_x Added by Des Small, 24 February 2012 Setup group: 5 Station: ZELENCHK Total bit rate: 512 Format: MARK5B Bits per sample: 2 Sample rate: 16.000 Number of channels: 16 DBE type: Speedup factor: 1.00 Disk used to record data. 1st LO= 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 8080.00 Net SB= L L U U L L U U L L U U L L U U Pol. = RCP LCP RCP LCP RCP LCP RCP LCP RCP LCP RCP LCP RCP LCP RCP LCP BBC = 1 9 1 9 2 10 2 10 3 11 3 11 4 12 4 12 BBC SB= L L U U L L U U L L U U L L U U IF = A B A B A B A B A B A B A B A B The following frequency sets based on these setups were used. Frequency Set: 7 Setup file default. LO sum= 8391.49 8391.49 8391.49 8391.49 8407.49 8407.49 8407.49 8407.49 8423.49 8423.49 8423.49 8423.49 8439.49 8439.49 8439.49 8439.49 BBC fr= 311.49 311.49 311.49 311.49 327.49 327.49 327.49 327.49 343.49 343.49 343.49 343.49 359.49 359.49 359.49 359.49 Bandwd= 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 Matching frequency sets: 7 8 9 Track assignments are: track1= 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32 barrel=roll_off SOURCES USED IN RECORDING SCANS -- X band NME+FTP-FT Experiment 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) * J1751+0939 17 49 10.387929 * 17 51 32.818572 17 52 11.762260 0.10 1749+096 09 39 42.82574 * 09 39 00.72829 09 39 06.27166 0.10 J1751+09 /aps3/sched10.2/catalogs/sources.vlba rfc_2012b Petrov, 2012, unpublished 133560 observations 0.250 scan and 19.500 baseline hours in setup: sess313.X512 Frequency sets (dups not shown): 1 2 3 4 5 6 7 10 11 12 13 * J1850+2825 18 48 29.069767 * 18 50 27.589825 18 51 00.058301 0.16 1848+283 28 21 38.48500 * 28 25 13.15523 28 26 35.21469 0.19 J1850+28 /aps3/sched10.2/catalogs/sources.vlba rfc_2012b Petrov, 2012, unpublished 71 observations 0.283 scan and 22.100 baseline hours in setup: sess313.X512 Frequency sets (dups not shown): 1 2 3 4 5 6 7 10 11 12 13 * J1925+2106 19 23 49.792391 * 19 25 59.605354 19 26 35.488565 0.11 1923+210 21 00 23.30482 * 21 06 26.16190 21 08 28.42838 0.10 J1925+21 /aps3/sched10.2/catalogs/sources.vlba rfc_2012b Petrov, 2012, unpublished 32646 observations 1.067 scan and 70.050 baseline hours in setup: sess313.X512 Frequency sets (dups not shown): 1 2 3 4 5 6 7 10 11 12 13 * J1931+2243 19 29 16.894885 * 19 31 24.916779 19 32 00.333106 0.11 1929+226 22 37 06.35047 * 22 43 31.25849 22 45 40.08861 0.10 J1931+22 /aps3/sched10.2/catalogs/sources.vlba rfc_2012b Petrov, 2012, unpublished 3020 observations 0.750 scan and 58.500 baseline hours in setup: sess313.X512 Frequency sets (dups not shown): 1 2 3 4 5 6 7 10 11 12 13 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) J1751+0939 54.0 J1850+2825 75.1 J1925+2106 79.4 J1931+2243 81.2 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