October 2009 band 3 beam scans

Using Band 7 BEAm Scanner Test source (BEAST) without the multiplier

  • Shows bad leakage

Scan Images Polarization Orientation Tilt (deg) Frequency Sideband AMC-E V_drain Pol. eff on secondary
2 1 co 0 100 USB 1.74 99.4237% = -22.39dB
3 cross 0 100 USB

Using Band 3 BEAST without the power amp

  • LO power of Band 3 BEAST can be adjusted by lowering the drain voltage of final AMC stage (stage E).
    • This is accomplished by setting negative values of the gate voltage in the Labview window (-1.50V used on March 2, 2010, which gave -62dB IF power on NSI strip chart; -1.0V gave -52dB).
    • The gate voltage in reality does not change -- suggesting either a software error, or that hardware lines are swapped).
  • In all cases, the cross pol scans have 20dB extra gain (compared to co pol scans).

Scan Images Polarization Orientation Tilt (deg) Frequency Sideband AMC-E V_drain Pol. Eff
5 1 cross 0 100 USB 0.57 99.4411% = -22.53dB
6 co 0 100 USB
7 0 co 0 100 USB 99.6244% = -24.25dB
8 cross 0 100 USB
9 1 co 45 100 USB 99.5210% = -23.20dB
10 cross 45 100 USB
11 0 co 45 100 USB 99.5952% = -23.93dB
12 cross 45 100 LSB
13 1 co 45 115 USB 1.48  
14 cross 45 115 USB
15 0 co 45 115 USB  
16 cross 45 115 USB
17 0 co 45 85 LSB 1.54 97.7149% = -16.41dB
18 cross 45 85 LSB
19 1 co 45 85 LSB 97.7554% = -16.49dB
20 cross 45 85 LSB
21 0 co 45 115 USB    
22 cross 45 115 USB    
23 1 co 45 115 USB    
24 cross 45 115 USB    
25 1 cross 45 85 LSB   99.8429% = -28.04dB
26 1 co 45 85 LSB  

-- ToddHunter - 2009-10-15

Topic attachments
I Attachment Action Size Date Who Comment
pol0.pngpng pol0.png manage 280 K 2009-10-15 - 11:45 ToddHunter 100 GHz polarization 0 tilt=0 images
pol0_100_45.pngpng pol0_100_45.png manage 287 K 2009-10-18 - 20:02 ToddHunter 100 GHz Pol0 tilt45
pol0_115_45.pngpng pol0_115_45.png manage 284 K 2009-10-19 - 12:50 ToddHunter 115 GHz pol 0 tilt 45
pol0_85_45.pngpng pol0_85_45.png manage 372 K 2009-10-19 - 12:51 ToddHunter 85 GHz pol0 tilt45
pol1.pngpng pol1.png manage 269 K 2009-10-15 - 11:45 ToddHunter 100 GHz pol 1 tilt=0 images
pol1_100_45.pngpng pol1_100_45.png manage 271 K 2009-10-18 - 20:01 ToddHunter 100 GHz pol1 tilt45
pol1_115_45.pngpng pol1_115_45.png manage 294 K 2009-10-19 - 12:50 ToddHunter 115 GHz pol 1 tilt 45
pol1_85_45.pngpng pol1_85_45.png manage 369 K 2009-10-19 - 12:51 ToddHunter 85 GHz polarization 1 tilt 45
pol1_85_45_2.pngpng pol1_85_45_2.png manage 346 K 2009-10-20 - 16:07 ToddHunter 85 GHz pol 1 tilt 45
pol1_band7beast.pngpng pol1_band7beast.png manage 317 K 2009-10-15 - 11:46 ToddHunter 100 GHz pol 1 tilt=0 images using band 7 beast (showing leakage)
This topic: ALMA > WebHome > FrontEndIntegrationCenter > FEICBeamScanningResults > Band3_October2009beamscans
Topic revision: 2010-12-21, ToddHunter
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding NRAO Public Wiki? Send feedback