Summary of Engineering Checkout

rev. 12/27/02

Passes

Mode Name

Description

Sampling

Number

Number of

Polarization

Which

Switc

Which

fits file

Comments

Engineering

Astronom.

Bandwidth

levels

of Samplers

quadrants

Cross_prod.

Quadrants

S/R

CAL

Bland

samplers

Checkout

fits file directory: /home/gbtdata/

Atest/Spectrometer

1N1-0A-12-9

12.5 MHz

LSS 0

2002_04_25_15:01:55A

Approved by Rick; see low level 6 KHz harmonics

2N1-4A-12-9

12.5 MHz

0, 1

LSS 0

2002_04_25_15:16:41A

Approved by Rick; see low level 6 KHz harmonics

4N1-6A-12-9

12.5 MHz

0, 1, 2, 3

LSS 0

2002_04_25_18:47:05A

Approved by Rick; see low level 6 KHz harmonics

1N1-0A-12-9

12.5 MHz

LSS 0

2002_06_18_14:38:45A

Approved by Rick

4N1-6A-12-9

12.5 MHz

0, 1, 2, 3

LSS 0

2002_08_28_17:33:17A

Approved by Rick; birdies in spectrum are from the test fixture.

4N1-6B-12-9

12.5 MHz

0, 1, 2, 3

LSS 8

2002_08_28_18:05:39A

Approved by Rick; birdies in spectrum are from the test fixture.

4N1-6C-12-9

12.5 MHz

0, 1, 2, 3

LSS 16

Advertised mode that needs to be tested.

4N1-6D-12-9

12.5 MHz

0, 1, 2, 3

LSS 24

Advertised mode that needs to be tested.

1N2-2C-12-9

12.5 MHz

LSS 16, 20

2002_05_13_19:02:02C

Approved by Rick

1N2-3D-12-9

12.5 MHz

LSS 24, 28

2002_05_13_19:02:02D

Approved by Rick

2N2-4A-12-9

12.5 MHz

0, 1

LSS 0, 4

2002_04_25_19:02:20A

Approved by Rick; high offset in second channel due to offset in sampler

4N2-6A-12-9

12.5 MHz

0, 1, 2, 3

LSS 0, 4

2002_04_25_19:21:55A

Approved by Rick; high offset in second channel due to offset in sampler

1N2-0A-12-9

12.5 MHz

LSS 0, 4

2002_06_18_17:04:56A

Approved by Rick

4N2-6A-12-9

12.5 MHz

0, 1, 2, 3

LSS 0, 4

2002_08_28_17:39:37A

Approved by Rick; birdies in spectrum are from the test fixture. There are very small
(1/500,000 of zero lag value) level difference in the four quadrants. This is probably the
cause of ringing one sees at the very low frequency end of the spectrum.

4N2-6B-12-9

12.5 MHz

0, 1, 2, 3

LSS 8, 12

2002_08_28_18:17:54A

Approved by Rick; birdies in spectrum are from the test fixture.

4N2-6C-12-9

12.5 MHz

0, 1, 2, 3

LSS 16, 20

Advertised mode that needs to be tested.

4N2-6D-12-9

12.5 MHz

0, 1, 2, 3

LSS 24, 28

Advertised mode that needs to be tested.

1N4-0A-12-9

12.5 MHz

LSS 0, 1, 4, 5

2002_08_6_14:33:49A

Approved by Rick

1N4-1B-12-9

12.5 MHz

LSS 8, 9, 12, 13

2002_05_13_17:31:48B

Rick examined. Found problems that need to be resolved

1N4-2C-12-9

12.5 MHz

LSS 16, 17, 20, 21

2002_05_13_18:13:12C

Rick examined. Found problems that need to be resolved

1N4-3D-12-9

12.5 MHz

LSS 24, 25, 28, 29

2002_05_13_18:42:29D

Rick examined. Found problems that need to be resolved

2N4-4A-12-9

12.5 MHz

LSS 0, 1, 4, 5

2002_08_6_18:51:32A

Approved by Rick. Need to fix offset in sampler 3

2N4-5B-12-9

Test in multi-bank mode. Find cause of subtle structure in smoothed spectrum

4N4-6A-12-9

12.5 MHz

0, 1, 2, 3

LSS 0, 1, 4, 5

2002_08_28_17:43:18A

Approved by Rick; birdies in spectrum are from the test fixture.

4N4-6B-12-9

12.5 MHz

0, 1, 2, 3

LSS 8, 9, 12, 13

2002_08_28_18:21:49A

Approved by Rick; birdies in spectrum are from the test fixture.

4N4-6C-12-9

12.5 MHz

0, 1, 2, 3

LSS 16, 17, 20, 21

Advertised mode that needs to be tested.

4N4-6D-12-9

12.5 MHz

0, 1, 2, 3

LSS 24, 25, 28, 29

Advertised mode that needs to be tested.

1N8-0A-12-9

12.5 MHz

LSS 0, 1,2,3,4,5,6,7

2002_12_10_14:07:53A.fi

all stectra and acf look okay send to Rick to check

1N8-0B-12-9

12.5 MHz

LSS 8,9,10,11,12,13,14,15

Required mode; needs to be tested

2N8-4A-12-9

12.5 MHz

0, 1

LSS 0, 1,2,3,4,5,6,7

!!!! Illegal mode !!!!

Required mode; needs to be tested

2N8-4B-12-9

12.5 MHz

0, 1

LSS 8,9,10,11,12,13,14,15

!!!! Illegal mode !!!!

Required mode; needs to be tested

1N1-0A-12-3

12.5 MHz

LSS 0

2002_04_25_15:16:41A

Approved by Rick

2N1-4A-12-3

12.5 MHz

0, 1

LSS 0

2002_04_25_15:24:53A

Approved by Rick

4N1-6A-12-3

12.5 MHz

0, 1, 2, 3

LSS 0

2002_04_25_18:51:33A

Approved by Rick

1N2-0A-12-3

12.5 MHz

LSS 0, 4

2002_04_25_19:00:30A

Approved by Rick; high offset in second channel due to offset in sampler

2N2-4A-12-3

12.5 MHz

0, 1

LSS 0, 4

2002_04_25_19:03:47A

Approved by Rick; high offset in second channel due to offset in sampler

4N2-6A-12-3

12.5 MHz

0, 1, 2, 3

LSS 0, 4

2002_04_25_19:31:22A

Approved by Rick; high offset in second channel due to offset in sampler

4N4-6A12-3

12.5 MHz

0, 1, 2, 3

LSS 0, 1, 4, 5

2002_08_28_17:10:51A

Approved by Rick; birdies in spectrum are from the test fixture.

4N4-6B-12-3

12.5 MHz

0, 1, 2, 3

LSS 8, 9, 12, 13

2002_08_28_18:26:21A

Approved by Rick; birdies in spectrum are from the test fixture.

4N4-6C-12-3

12.5 MHz

0, 1, 2, 3

LSS 16, 17, 20, 21

Advertised mode that needs to be tested.

4N4-6D-12-3

12.5 MHz

0, 1, 2, 3

LSS 24, 25, 28, 29

Advertised mode that needs to be tested.

1N8-0A-12-3

12.5 MHz

LSS 0, 1,2,3,4,5,6,7

2002_09_13_19:48:27A

Approved by Rick

2N8-4A-12-3

12.5 MHz

0, 1

LSS 0, 1,2,3,4,5,6,7

2002_09_13_19:50:40A

Approved by Rick

4N8-6A-12-3

12.5 MHz

0, 1, 2, 3

LSS 0, 1,2,3,4,5,6,7

2002_09_13_19:52:53A

Last quarter of lag values in channels 1, 2, 3, 4, and 8 are slightly higher than other lag
values. There's a hint of this offset in channels 5, 6, 7, but it's not as obvious. Spectra
look OK but need to find the cuase of the problem with the ACF values.
Retested 10_22_02. Same result. 2002_10_22_14:40:00A.

Note: 32 sampler modes not available due to IF limitations

Note: 8 and 16 sampler modes advertised on the web are obtained by using combinations of 2 and
4 samplers modes in 2 and 4 quadrants.

1N2-0A-50-9

50 MHz

LSS 0,4

2002_08_29_14:45:14A

Approved by Rick

4N1-6A-50-9

50 MHz

0,1,2,3

LSS 0

2002_08_29_14:53:44A

Approved by Rick

4N2-6A-50-9

50 MHz

0,1,2,3

LSS 0,4

2002_08_29_14:59:03A

Approved by Rick

1N4-0A-50-9

50 MHz

LSS 0,1,4,5

2002_08_06_15:45:33A

Approved by Rick

2N4-4A-50-9

50 MHz

0, 1

LSS 0,1,4,5

2002_08_06_15:50:04A

Approved by Rick. Tested in multi-bank mode. Fix offset in LSS 4

2N4-5B-50-9

50 MHz

2,3

LSS 8, 9, 12, 13

2002_12_11_20:46:23B

Approved by Rick. Tested in multi-bank mode. Fix offset in LSS 4

4N4-6A-50-9

50 MHz

0,1,2,3

LSS 0,1,4,5

2002_08_22_16:07:41A

Approved by Rick

1N4-0B-50-9

50 MHz

LSS 8, 9, 12, 13

2002_08_07_20:24:42A

Approved by Rick

2N4-4B-50-9

50 MHz

0, 1

LSS 8, 9, 12, 13

2002_08_07_20:27:40A

Approved by Rick

4N4-6B-50-9

50 MHz

0, 1, 2, 3

LSS 8, 9, 12, 13

2002_10_21_18:39:24A

Approved by Rick

1N1-0A-50-9

50 MHz

LSS 0

2002_08_29_15:03:57A

Approved by Rick

1N8-0A-50-9

50 MHz

LSS 0, 1, 2, 3, 4, 5, 6, 7

2002_09_13_19:43:05A

Approved by Rick

1N8-0B-50-9

50 MHz

LSS 8, 9, 10, 11, 12, 13, 14

Required mode; needs to be tested, high priority.

4N8-6A-50-9

50 MHz

0,1,2,3

LSS 0,1,2,3,4,5,6,7

!!!! Illegal mode !!!!

Required mode; need to test.

2N4-4A-50-3

50 MHz

0, 1

LSS 0,1,4,5

2002_09_05_16:47:07A

Approved by Rick; birdies in spectrum are from the test fixture.

1N1-0A-50-3

50 MHz

check?

2002_09_11_15:20:09A

Approved by Rick

4N1-6A-50-3

50 MHz

0,1,2,3

LSS 0

2002_08_28_13:18:03A

Approved by Rick; birdies in spectrum are from the test fixture.

4N1-6B-50-3

50 MHz

0,1,2,3

LSS 8

2002_08_28_18:43:14A

Approved by Rick; birdies in spectrum are from the test fixture.

4N1-6C-50-3

50 MHz

0,1,2,3

LSS 16

2002_08_29_18:56:32A

Approved by Rick; birdies in spectrum are from the test fixture.

4N1-6D-50-3

50 MHz

0,1,2,3

LSS 24

2002_09_05_17:31:51A

Advertised mode that needs to be tested. ACF has glitches. Needs work
retsted 10_22_02. 2002_10_22_12:23:23A, 2002_10_22_12:40:46A
2002_10_22_12:43:58A

4N2-6A-50-3

50 MHz

0,1,2,3

LSS 0, 4

2002_08_28_15:06:41A

Approved by Rick; birdies in spectrum are from the test fixture.

4N2-6B-50-3

50 MHz

0,1,2,3

LSS 8, 12

2002_08_28_18:40:29A

Approved by Rick; birdies in spectrum are from the test fixture.

4N2-6C-50-3

50 MHz

0,1,2,3

LSS 16, 20

2002_08_29_19:02:02A

Approved by Rick; birdies in spectrum are from the test fixture.

4N2-6D-50-3

50 MHz

0,1,2,3

LSS 24, 28

2002_09_05_17:48:49A

Advertised mode that needs to be tested. ACF has glitches. Needs work
Retsted 10_22_02. 2002_10_22_13:01:08A, 2002_10_22_13:09:36A

4N4-6A-50-3

50 MHz

0,1,2,3

LSS 0, 1, 4, 5

2002_08_28_15:16:31A

Approved by Rick; birdies in spectrum are from the test fixture.

4N4-6B-50-3

50 MHz

0,1,2,3

LSS 8, 9, 12, 13

2002_08_28_18:35:29A

Approved by Rick; birdies in spectrum are from the test fixture.

4N4-6C-50-3

50 MHz

0,1,2,3

LSS 16, 17, 20, 21

2002_09_05:18:09:24A

Advertised mode that needs to be tested. ACF has glitches. Needs work.

4N4-6D-50-3

50 MHz

0,1,2,3

LSS 24, 25, 28, 29

2002_09_05_17:56:39A

Advertised mode that needs to be tested. ACF has glitches. Needs work
retested 10_22_02. 2002_10_22_13:42:24A, 2002_10_22_13:51:06A
2002_10_22_14:06:40A with same result.

1N8-0A-50-3

50 MHz

LSS 0, 1, 2, 3, 4, 5, 6, 7

2002_09_13_19:36:22A

Approved by Rick

2N8-4A-50-3

50 MHz

0, 1

LSS 0, 1, 2, 3, 4, 5, 6, 7

2002_09_13_19:38:47A

Approved by Rick

4N8-6A-50-3

50 MHz

0, 1, 2, 3

LSS 0, 1, 2, 3, 4, 5, 6, 7

2002_09_13_19:40:54A

Looks OK except for excess amplitude in the ACF for channel 7, lags > 31000

Note: 50 MHz BW using high-speed samplers is NOT available, despite being advertised on web

Note: 32 sampler modes not available due to IF limitations

Note: 8 and 16 sampler modes advertised on the web are obtained by using combinations of 2 and
2 samplers modes in 2 and 4 quadrants.

1W1-00-200

200 MHz

HSS 0

2002_06_18_13:58:13A

Filter is >200 MHz wide. Approved by Rick. Birdies in passband are from test fixture.

1W1-11-200

200 MHz

HSS 1

2002_06_05_18:18:34B

Rich needs to re-test with Ray's fix.

4W1-60-200

200 MHz

0, 1, 2, 3

HSS 0

2002_06_06_14:58:29A

Rich needs to re-test with Ray's fix.

1W2-001-200

200 MHz

HSS 0,1

2002_10_11_15:53:07A

Filter is >200 MHz wide. Approved by Rick. Birdies in passband are from test fixture.

1W2-123-200

200 MHz

HSS 2, 3

2002_10_11_19:05:10B

Filter is >200 MHz wide. Approved by Rick. Birdies in passband are from test fixture.

1W2-245-200

200 MHz

HSS 4, 5

2002_10_11_19:11:42C

Sampler 4 looks OK. Possible problem with sampler 5. Rick to evaluate.

1W2-067-200

200 MHz

HSS 6, 7

2002_10_14_13:16:24A

Filter is >200 MHz wide. Approved by Rick. Birdies in passband are from test fixture.

1W2-367-200

200 MHz

HSS 6, 7

2002_10_14_12:51:17D

ACF looks terrible. Possibly multibank problem. Re-test when multibank is fixed.

2W2-401-200

200 MHz

0,1

HSS 0,1

2002_10_23_13:32:47A

Filter is >200 MHz wide. Approved by Rick. Birdies in passband are from test fixture.

1W4-00123-200

200 MHz

HSS 0, 1, 2, 3

2002_10_14_14:19:23A

Filter is >200 MHz wide. Approved by Rick. Birdies in passband are from test fixture.

1W4-14567-200

200 MHz

HSS 4, 5, 6, 7

Required mode; need to test.

4W2-401-200

200 MHz

0, 1

HSS 0, 1

2002_10_14_14:11:02A

Filter is >200 MHz wide. Approved by Rick. Birdies in passband are from test fixture.

4W2-601-200

200 MHz

0, 1, 2, 3

HSS 0,1

2002_10_14_14:01:56A

Filter is >200 MHz wide. Approved by Rick. Birdies in passband are from test fixture.

2w4-40123-200

200 MHz

0, 1

HSS 0, 1, 2, 3

!!!!illegal mode!!!!

Required mode; needs to be tested, high priority.

note: double nyquist sampling is NOT available in 200 MHz BW, despite being advertised on web

Note: The 8 sampler mode advertised on the web is obtained by using combinations of 2 and 4
sampler modes in 2 and 4 quadrants.

1W1-00-800

800 MHz

HSS 0

2002_10_14_15:15:36A

Need to retest with better analog filter shape

2W1-40-800

800 MHz

0,1

HSS 0

2002_10_14_15:31:06A

Need to retest with better analog filter shape

2W1-50-800

800 MHz

2,3

HSS 0

4W1-60-800

800 MHz

0,1,2,3

HSS 0

2002_10_14_15:27:26A

Need to retest with better analog filter shape

2W1-40-800

800 MHz

0,1

HSS 0

2002_3_18_20:27:07A.fits

Need to account for 8 db slope and 100 MHz birdie.

2W1-52-800

800 MHz

2,3

HSS 2

2002_3_18_20:27:07B.fits

Need to account for 8 db slope and 100 MHz birdie.

1W1-00-800

800 MHz

HSS 0

2002_03_27_18:31:47A.fits

Rick has analyzed the transfer function. Need to account for 10 db slope across passband.

1W1-01-800

800 MHz

HSS 1

2002_11_26_15:17:48A.fits

Approved by Rick

1W1-02-800

800 MHz

HSS 2

2002_11_26_15:17:48A.fits

Approved by Rick

1W1-03-800

800 MHz

HSS 3

2002_11_26_15:26:00A.fits

Approved by Rick

1W1-04-800

800 MHz

HSS 4

2002_11_26_15:30:54A.fits

Approved by Rick

1W1-05-800

800 MHz

HSS 5

2002_11_26_15:36:11A.fits

Approved by Rick

1W1-06-800

800 MHz

HSS 6

2002_11_26_15:42:09A.fits

Approved by Rick

1W1-07-800

800 MHz

HSS 7

2002_11_26_15:45:53A.fits

Approved by Rick

1W1-11-800

1W1-22-800

1W1-33-800

Test in multi-bank config

1w2-123-800

800 MHz

HSS 2,3

2002_12_06_16:00:39A.fits

retested, waiting for Rick to check

1W2-001-800

800 MHz

HSS 0, 1

2002_12_06_15:50:17A.fits

retested, waiting for Rick to check

2W1-40-800

800 MHz

0,1

HSS 0

2002_04_04_21:16:10A.fits

P/O 800 MHz, 2IF. Need to account for 14 db slope across passband; high priority

2W1-52-800

800 MHz

2,3

HSS 2

2002_04_04_21:16:10B.fits

P/O 800 MHz, 2IF. Need to account for 14 db slope across passband; high priority

800 MHz

0, 1, 2, 3

a few combinations

Advertised mode that needs to be tested.

2W1-52-800

800 MHz

2,3

HSS 2

2002_04_04_21:16:10B.fits

P/O 800 MHz, 2IF. Need to account for 14 db slope across passband

4W2-601-800

800 MHz

0, 1, 2, 3

HSS 0, 1

Required mode; needs to be tested, high priority.

Note: 4 and 8 sampler modes advertised on the web are obtained by using combinations of 2
sampler modes in 2 and 4 quadrants.

1N2P-0A-12-9

12.5 MHz

Yes

LSS 0, 4

2002_06_24_17:14:54A.fits

OK with identical signals. Need to check with more realistic signals.

2N2P-4A-12-9

12.5 MHz

Yes

0,1

LSS 0, 4

2002_06_24_19:27:27A.fits

OK with identical signals. Need to check with more realistic signals.

4N2P-6A-12-9

12.5 MHz

Yes

0,1,2,3

LSS 0, 4

2002_06_24_19:31:00A.fits

OK with identical signals. Need to check with more realistic signals.

1N4P-0A-12-9

12.5 MHz

Yes

LSS 0, 1, 4,5

2002_06_24_19:38:00A.fits

Per Rick, has negative power in cross products.

2N4P-4A-12-9

12.5 MHz

Yes

0,1

LSS 0, 1, 4,5

Illegal mode due to hardware limitations

4N4P-6A-12-9

12.5 MHz

Yes

0,1,2,3

LSS 0, 1, 4,5

Illegal mode due to hardware limitations

1N2P-0A-12-3

12.5 MHz

Yes

LSS 0, 4

2002_06_24_19:44:11A.fits

Per Rick, has negative power in cross products.

2N2P-4A-12-3

12.5 MHz

Yes

0,1

LSS 0, 4

2002_06_24_19:47:28A.fits

Per Rick, has negative power in cross products.

4N2P-6A-12-3

12.5 MHz

Yes

0,1,2,3

LSS 0, 4

2002_06_24_19:50:09A.fits

Per Rick, has negative power in cross products.

1N4P-0A-12-3

12.5 MHz

Yes

LSS 0, 1, 4, 5

2002_06_24_19:52:44A.fits

Per Rick, has negative power in cross products. Xprods 3 & 4 really bad.

2N4P-4A-12-3

12.5 MHz

Yes

0, 1

LSS 0, 1, 4, 5

2002_06_24_19:54:30A.fits

Per Rick, has negative power in cross products. Xprods 3 & 4 really bad.

4N4P-6A-12-3

12.5 MHz

Yes

0,1,2,3

LSS 0, 1, 4, 5

2002_06_24_19:56:37A.fits

Per Rick, has negative power in cross products. Xprods 3 & 4 really bad.

Note: 8 and 16 sampler modes advertised on the web are obtained by using combinations of 2 and
4 samplers modes in 2 and 4 quadrants.

1N2P-0A-50-9

50 MHz

Yes

LSS 0, 4

2002_06_24_19:59:40A.fits

OK with identical signals. Need to check with more realistic signals.

2N2P-4A-50-9

50 MHz

Yes

0,1

LSS 0, 4

2002_06_24_20:02:37A.fits

OK with identical signals. Need to check with more realistic signals.

4N2P-6A-50-9

50 MHz

Yes

0,1,2,3

LSS 0, 4

2002_06_24_20:04:26A.fits

OK with identical signals. Need to check with more realistic signals.

1N4P-0A-50-9

50 MHz

Yes

LSS 0, 1, 4, 5

2002_06_24_20:05:58A.fits

Per Rick, has negative power in cross products. Xprods 3 & 4 really bad.

2N4P-4A-50-9

50 MHz

Yes

0,1

LSS 0, 1, 4, 5

Illegal mode due to hardware limitations

4N4P-6A-50-9

50 MHz

Yes

0,1,2,3

LSS 0, 1, 4, 5

Illegal mode due to hardware limitations

Note: 32 sampler modes are not available due to IF limitations, despite being advertised on the we

1N2P-0A-50-3

50 MHz

Yes

LSS 0, 4

2002_06_24_20:12:41A.fits

OK with identical signals. Need to check with more realistic signals.

2N2P-4A-50-3

50 MHz

Yes

0,1

LSS 0, 4

2002_06_24_20:14:15A.fits

OK with identical signals. Need to check with more realistic signals.

4N2P-6A-50-3

50 MHz

Yes

0,1,2,3

LSS 0, 4

2002_06_24_20:15:54A.fits

OK with identical signals. Need to check with more realistic signals.

1N4P-0A-50-3

50 MHz

Yes

LSS 0, 1, 4, 5

2002_06_24_20:17:42A.fits

Per Rick, has negative power in cross products. Xprods 3 & 4 really bad.

2N4P-4A-50-3

50 MHz

Yes

0,1

LSS 0, 1, 4, 5

2002_06_24_20:19:11A.fits

Per Rick, has negative power in cross products. Xprods 3 & 4 really bad.

4N4P-6A-50-3

50 MHz

Yes

0,1,2,3

LSS 0, 1, 4, 5

2002_06_24_20:21:03A.fits

Per Rick, has negative power in cross products. Xprods 3 & 4 really bad.

Note: 8 and 16 sampler modes advertised on the web are obtained by using combinations of 2 and
2 samplers modes in 1 , 2 and 4 quadrants.

200 MHz

Yes

0,1,2,3

a few combinations

Advertised mode that needs to be tested.

200 MHz

Yes

0,1,2,3

a few combinations

Advertised mode that needs to be tested.

note: double nyquist sampling is NOT available in 200 MHz BW, despite being advertised on web

Note: the 8 sampler mode advertised on the web is obtained by using combinations of 2 or 4
samplers modes in 2 and 4 quadrants.

800 MHz

Yes

various

a few combinations

Advertised mode that needs to be tested.

Note: 4 and 8 sampler modes advertised on the web are obtained by using combinations of 2
samplers modes in 2 and 4 quadrants.

GBT Spectrometer Mode Nomenclature

Modes in the GBT spectrometer are named using a few simple conventions. The

first 3 digits of most spectrometer modes are comprised of a number, a letter

and a number (pulsar modes have 4 initial digits). The first number in the

mode name is the number of quadrants required for the mode. The possible

values for this first digit are;

1 indicates a mode occupying 1 spectrometer quadrant

2 indicates a mode occupying 2 spectrometer quadrants

4 indicates a mode occupying 4 spectrometer quadrants

The next letter (letters for pulsar modes) indicated the type of mode. The

possible letters for this second digit are;

W indicates a 800 MHz or 200 MHz bandwidth mode

N indicates a 50 MHz or 12.5 MHz bandwidth mode

PW indicates a pulsar mode using the 1.6 GHz samplers

PN indicates a pulsar mode using the 100 MHz samplers

The last of the 3 initial digits in a spectrometer mode name gives the number

of active samplers the mode uses. The possible values for this third digits

are;

1 indicates a mode processing the output of one sampler

2 indicates a mode processing the output of two samplers

4 indicates a mode processing the output of four samplers

8 indicates a mode processing the output of eight samplers

If the letter P follows the 3rd digit (4th for pulsar modes), the mode

produces polarization cross products.

After the first dash, the first digit specifies which quadrant or group of quadrants is used

The possible values for this digit are:

0 indicates quadrant 0

1 indicates quadrant 1

2 indicates quadrant 2

3 indicates quadrant 3

4 indicates quadrants 0 and 1

5 indicates quadrants 2 and 3

6 indicates quadrants 0, 1, 2, and 3

The rest of the characters after the first dash depend on whether the modes is a

wide-band mode ("W" for the second digit in the first group) or

narrow-band mode ("N" for the second digit in the first group)

For wideband mode, up to four charaters may follow the initial digit.

The specify the number(s) of the sampler(s) used and can each range from

0 to 7. They should be in ascending order.

For narrow-band mode, a single letter follow the initial number after the first dash

The letter indicates which group of samplers is used for this mode. The possible

values include:

A for samplers 0 to 7

B for samplers 8 to 15

C for sampelrs 16 to 23

D for samplers 24 to 31

see Table I below for the allocation of sampler numbers for all groups and number of samplers.

The numbers after the second dash indicate the bandwidth of the mode. Possible

values include

800 for 800 MHz bandwidth

200 for 200 MHz bandwidth

50 for 50 MHz bandwidth

12 for 12.5 MHz bandwidth.

For narrow band modes, there is a third dash in the mode specification to indicate

the number of sampling levels. Possible values include

If a spectrometer mode using the low speed samplers is followed by -3 or -9

the mode indicated is a 3-level or 9-level operation respectively.

3 for 3-level sampling

9 for 9-level sampling.

Pulsar modes have a -1024, -512 or -256 following the initial 4 digit field.

This number gives the number of time bins produced by the mode.

Table I

Sampler Numbers for all sampler group and numbers of samplers

Sampler Group

Number of Samplers

0, 4

8, 12

16, 20

24, 28

0, 1, 4, 5

8, 9, 12, 13

16, 17, 18,

24, 25, 28, 29

0 to 7

8 to 15

16 to 23

24 to 31