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lbaops:mopranotessetup [2008/07/09 13:46]
chris.phillips
lbaops:mopranotessetup [2009/11/27 16:15]
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 ====  Linear - Circular conversion ==== ====  Linear - Circular conversion ====
  
-All Mopra receivers produce linear polarizations. These are converted to circulars through tunable hybrids. Generally only the C-band need to be tuned (when changing between 6.7 and 4.8 GHz).+All Mopra receivers produce linear polarizations. These are converted to circulars through tunable hybrids. Generally only the C-band need to be tuned (when changing between 6.7 and 4.8 GHz). Such tuning is done manually and need ATNF staff at Mopra.
  
 ====  IF cabling ==== ====  IF cabling ====
  
-Rcp and Lcp from IF#1 comes from the equipment room on cables C13 and C31. IF#2 comes down cables ​XX and XX (Rcp and Lcp respectively).+Rcp and Lcp from IF#1 comes from the equipment room on cables C13 and C31. IF#2 comes down cables ​CC11 and CC13 (Rcp and Lcp respectively).
  
-These are normally connected directly to DAS1 and DAS2. Historically for Lcp only experiments one had to re-cable Lcp (ie C31) to DAS IFP#1 input. However depending on the experiment this is probably not required and a suitable "disko" channel selection can be used.+These are normally connected directly to DAS1 and DAS2. Historically for Lcp only experiments one had to re-cable Lcp (ie C31) to DAS IFP#1 input. However depending on the experiment this is probably not required and a suitable "cdisko" channel selection can be used.
  
 ====  Coherence test/test tone ==== ====  Coherence test/test tone ====
  
-**//There is a remotely accessible CRO now. This has notes been tested, ​but Tasso and Chris have some notes on how to access this over the network//​** ​+This has to be done with a CRO locally. ​There are plans for a remotely accessible CRO but it is not yet operational.
  
-To test coherence, you need to inject a test tone 5 MHz above the lower band edge first IFP channel. For the normal 16 MHz "​vsop"​ profiles this means injecting a tone MHz //below// the tuning frequency. ​Use ''​mmdrive''​ to turn on the test tone:+To test coherence, you need to inject a test tone 5 MHz above the lower band edge first IFP channel. For the normal 16 MHz "​vsop"​ profiles this means injecting a tone 11 MHz //below// the tuning frequency. ​
  
-Log onto bigrock as observer ​and run+The test tone is generated by Wiltron #2 (W-2), which is located in the control room downstairs (it leaks too much RFI when located in the vertex room) and can be controlled remotely.
  
- > ​mmdrive+One can use ''​mmdrive''​ to control W-1 and W-2 but that often had difficulties with W-2. 
 +{Useful mmdrive commands are 
 + > w:2 freq <​freq> ​  - to set the frequency 
 +> w:2 rflvl <​level> ​ - to set the level from -70 to +20 dBm 
 + w:2 rfon | rfoff   - to turn the output on or off}
  
-Set tone frequency+However, a special program ''​mmd''​ has been developed to control W-2 only. 
 +Commands are: 
 + > mmd - to get started 
 + > freq <MHz> - to set the frequency 
 + > rflvl <dBm> - to set the power level (-70 to +20) 
 + > rfon OR rfoff - to turn output on or off 
 + > status - to show what has been setup 
 + > quit - to exit mmd 
 + > ?  - to get a list of all commands.
  
- > w:2 freq <​freq>​+For a coherence test tone:
  
-Set power level (typically -20 to -10). Higher frequencies (e.g. 8 GHz) need more power.+Log onto bigrock as observer and run
  
- > ​w:2 rflvl <​level>​+ > ​mmd
  
-Turn tone on+ > freq <MHz> - to set test tone frequency (5 MHz above edge of band)
  
- > ​w:2 rfon+ > ​rflvl <dBm> - to set power level (typically -20 to -10). Higher frequencies (e.g. 8 GHz) may need more power (Up to +20 dBm).
  
-Look at the CRO in rack F(??). Input one is connected ​to the 5 MHz reference from the maser and is used as a trigger. Input two should be connected to DAS monitor port XXX, which should contain the test tone you have injected. If the system is coherence, you have got the right frequency and the band has the connect inversion (ie right DAS profile, you should see the test tone 5 MHz locked to the 5 MHz.+ > rfon - to turn tone on
  
-Turn tone off+Look at the CRO in rack F(??). Input one is connected to the 5 MHz reference from the maser and is used as a trigger. Input two should be connected to DAS monitor port XXX, which should contain the test tone you have injected. If the system is setup correctly (right DAS profile) and coherent, you should see the test tone 5 MHz locked to the 5 MHz from the reference.
  
- > ​w:2 rfoff+ > rfoff - to turn tone off
  
 When observing remotely, it is still worth turning the test tone on (at a lower power level) and recording some data and checking it is visible at the expected frequency using fauto. When observing remotely, it is still worth turning the test tone on (at a lower power level) and recording some data and checking it is visible at the expected frequency using fauto.
  
  
lbaops/mopranotessetup.txt · Last modified: 2015/12/18 16:39 (external edit)