Intro:

• 14nov13: test data taken on the crab
• 15nov13:scheduled observations on the crab

Reference material (for analysis)

• crab dispersion
• dm crab=56.77
• DM smearing across each 16 Mhz  band

• band	cfr Mhz	dm smearing Millisecs
  sband	2380.	0.559
  	2368.	0.568
  cband	4884.	0.065
  	4912.	0.064
  	4928.	0.063
  	4944.	0.062
  	4960.	0.062
  	4976.	0.061
  	4992.	0.061
  xband	9068.	0.010
  	9084.	0.010
  	9100.	0.010
  	9116.	0.010
  	9132.	0.010
  	9148.	0.010
  	9164.	0.010

  
  

Setups (14,15 nov13 crab)

Mock setup:

• 8 bit voltage sampling.
  
• 16 MHz bands are recorded (multiple bands per receiver).
• For each band 160 MHz complex baseband sampling is done.
• Inside the mock spectrometer:
• digital mix by -10 MHz for each band
• This is to move the A/D DC out of the processed band
• To compensate for this, the RF frequency is set 10MHz above the center of the band we actually want.
• digital filter with hanning window. filter then decimate by 10 to go 160  MHz to 16 MHz bandwidth
• record 8bit complex voltage samples

Receiver setups:

• multiple 16 MHz bands were   used for each receiver:
• 
  

• Recorded frequency bands for each receiver

  rcv	band 1	band  2	band 3	band 4	band 5	band 6	band 7
  sbn	2376-2392	2360-2376
  cband	4888-4904	4904-4920	4920-4936	4936-4952	4952-4968	4968-4984	4984-5000
  xband	9060-9076	9076-9092	9092-9108	9108-9124	9124-9140	9140-9156	9156-9172

  
  
• sband narrow
• receiver is native circular
  
• sky center frequency 2380
• mixing:
• to 1st IF: RF -> 750  MHz using 750 narrow band mixer.
  
• High side low
• 1stIF->2ndIF  750 -> 325 MHz. using high side low
• 2ndIF -> baseband. complex mixing
• Final band is in ascending freq order.
• attenuation
• used normal adjpower all 
• mock level adjust set to 25 a/d counts - 1 sigma
  
• cband
• native linear
  
• sky center 4950 MHz
• to 1st IF: RF -> 1500 MHz using 2 to 12 Ghz mixer.
• high side first lo
• 1st IF -> 2nd IF:  1500 -> 325 with high side lo,.
• 2ndIF -> baseband via complex mixing
• Final band is not flipped.
• attenuation
• added 15 db extra gain in the if2 power adjustment
• mock level adjust set to 35 a/d counts - 1 sigma
• xband
• native circular
  
• sky center 9025 MHz
• rf to 1st IF: rf ->  1500 MHz using 2 to 12 Ghz mixer
• 1st IF->2ndIF: 1500 -> 325 with high side lo
• all lbands should have used 1500 MHz if1 filter when mixing if1-> if2.
  
• yellow bands used the 1250 MHz if1 filter, so there is probably no signal in these two bands.
• Looks like a config error in cima.. Wrong value is stored in the config file.
• 2ndIF -> baseband via complex mixing
• Final band is not flipped
• attenuation
• added 19 db extra gain in the if2 power adjustment
• mock level adjust set to 35 a/d counts - 1 sigma

Data acquisition

    We did 10 minute on, 10 minute off observations followed by a short acquisition in the off position with the vlbical on

• Positions:
• on (crab) . ra,dec J2000: 05:34:31.973   +22:00:52.06
• offsrc12:    ra,dec J2000: 05:46:31.973   +22:00:52.06
• offsrc6  :    ra,dec J2000: 05:40:31.973   +22:00:52.06
• patterns:
• we did an 10 minute on source
• moved to 12 minutes off in ra to cover close to the same area of the dish
• 10 minutes of on , followed by about 1.5 minutes to move to the off position
• after the off, we turned the vlbical on and took data for 10 secs.
  
• This inserted a 1 MHz comb before the first mixer.
• files recorded
• All filenames start with
• a2880.20131115.bNs1g0.MMMMM.pdev
• N is the band 0 ..6
• M is the 5 digit file number
  

• Files recorded 15nov13

  startTm	rcvr	file number range	type
  01:56:05	sbn	000-017	on
  02:08:08		100-117	off
  02:20:45		200	off cal
  02:25:31	cband	300-317	on
  02:37:56		400-417	off
  02:48:32		500	off cal
  02:51:27	xband	600-617	on
  03:03:30		700-717	off
  03:14:05		800	off cal
  03:17:39	cband	900-917	on
  03:24:30		1000-1017	off
  03:30:06		1100	off cal

  
  

22mar14. 3C273, 3C274

Mock setup:

• 8 bit voltage sampling.
  
• 16 MHz bands are recorded (multiple bands per receiver).
• For each band 160 MHz complex baseband sampling is done.
• Inside the mock spectrometer:
• digital mix by -10 MHz for each band
• This is to move the A/D DC out of the processed band
• To compensate for this, the RF frequency is set 10MHz above the center of the band we actually want.
• digital filter with hanning window. filter then decimate by 10 to go 160  MHz to 16 MHz bandwidth
• record 8bit complex voltage samples

Receiver setups:

• multiple 16 MHz bands were   used for each receiver:
• Note (sbn was down so we used sbw).. linear pols
• 
  

• Recorded frequency bands for each receiver

  rcv	band 1	band  2	band 3	band 4	band 5	band 6	band 7
  sbw	2376-2392	2360-2376
  cband	4888-4904	4904-4920	4920-4936	4936-4952	4952-4968	4968-4984	4984-5000
  xband	9060-9076	9076-9092	9092-9108	9108-9124	9124-9140	9140-9156	9156-9172

  
  
• sband wide
  
• receiver is native linear
  
• sky center frequency 2380
• mixing:
• rf to 1st IF: RF -> 10ghz -> 1-2 ghz
  
• High side low
• 1stIF->2ndIF 1500->325 with high side lo
  
• 2ndIF -> baseband. complex mixing
• Final band is probably flipped
  
• attenuation
• need to check adjpwri2f -e x
  
• mock level adjust set to 25 a/d counts - 1 sigma
  
• cband
• native linear
  
• sky center 4950 MHz
• to 1st IF: RF -> 1500 MHz using 2 to 12 Ghz mixer.
• high side first lo
• 1st IF -> 2nd IF:  1500 -> 325 with high side lo,.
• 2ndIF -> baseband via complex mixing
• Final band is not flipped.
• attenuation
• added 15 db extra gain in the if2 power adjustment
• mock level adjust set to 35 a/d counts - 1 sigma
• xband
• native circular
  
• sky center 9025 MHz
• rf to 1st IF: rf ->  1500 MHz using 2 to 12 Ghz mixer
• 1st IF->2ndIF: 1500 -> 325 with high side lo
• all lbands should have used 1500 MHz if1 filter when mixing if1-> if2.
  
• yellow bands used the 1250 MHz if1 filter, so there is probably no signal in these two bands.
• Looks like a config error in cima.. Wrong value is stored in the config file.
• 2ndIF -> baseband via complex mixing
• Final band is not flipped
• attenuation
• added 19 db extra gain in the if2 power adjustment
• mock level adjust set to 35 a/d counts - 1 sigma

Data acquisition

    We did 10 minute on, 10 minute off observations followed by a short acquisition in the off position with the vlbical on

• Had setup a cmd file, but ended up doing it manually because of the attenuator offsets.
• --> be sure we are in full update rather than fast update mode in the if/lo window
  
• Positions:
• on (crab) . ra,dec J2000: 05:34:31.973   +22:00:52.06
• offsrc12:    ra,dec J2000: 05:46:31.973   +22:00:52.06
• offsrc6  :    ra,dec J2000: 05:40:31.973   +22:00:52.06
• patterns:
• we did an 10 minute on source
• moved to 12 minutes off in ra to cover close to the same area of the dish
• 10 minutes of on , followed by about 1.5 minutes to move to the off position
• after the off, we turned the vlbical on and took data for 10 secs.
  
• This inserted a 1 MHz comb before the first mixer.
• notes: tiedowns stopped did tiepos 73.. distomats weren't reading.
  
• files recorded
• All filenames start with
• a2880.20140322.bNs1g0.MMMMM.pdev
• N is the band 0 ..6
• M is the 5 digit file number
  

• Files recorded 22mar14

  startTm	src	rcvr	file number range	type
  00:13:xx	3c274	cband	000-017	on
  00:24:xx			100-107 b5s1g0 pi fifo error 0470	off
  			200	off cal
  		xband	300-317 vlbical was on the entire	offcal
  			400-404  5 minutes aborted after 50% b0s1g0 dma buffer overflow	off
  00:49			500-517	on
  01:04	3c273	xband	600-617	on
  01:15			700-717	off
  01:25			800	off cal
  01:28		cband	900-xx stopped at 5min to give more time for on srce was setting	off
  01:35			1000-xx went out of beam after 8 minutes	on
  01:46	3c274	cband	1100-1108 aborted 45% b6s1g0 dma buf overflow	on
  01:52		cband	1200-1217	on
  02:04		xband	1300-1317	on

  
  

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