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February 28, 2005 Prime Focus 800 MHz Receiver Checkout Report

IF Manager Linux Bug FIX

The IF Manager and the PF Support Rack are now both under linux (migrated from VxWorks). There is a bug that doesn't setup the If Manger correctly for the Prime Focus receivers. The workaround to fix this is:

• In IF Manager set both IFConditioner_RF_relay-switchA and IFConditioner_RF_relay-switchB to have the value of 2 if the PF Support Rack RF_relay_switch is set to StandardPF.
• IF the PF Support Rack RF_relay_switch is set to 1070MHz then the If Manager IFConditioner_RF_relay-switchA and IFConditioner_RF_relay-switchB values should be 1.

Codes Used In Report

== Everything was OK.
== Some problems but not critical.
== Critical problems encountered.

Notes

This receiver checkout was done during a snow storm. The antenna was not available to be moved.

The antenna was at an Azimuth of 44.15 degrees and at an elevation of 5.12 degrees.

Checkout Results

• 1. Check that the config_tool sets things up right.
  • Used the config script in /home/astro-util/projects/PF1800/setup.py
  • Setup failed.
    • CLEO message: Signal was routed only as far as PF_IF_Conditioners.
      • Signal was making it to the IF Rack.
      • Problem is either a bad cabling file or with the IF Manager?
        • Mark Clark was called and had us reload the cabling file.
        • Mark Clark finally found that the PF_Support Rack was not talking with the IF Manager correctly.
        • Problem was resolved.
    • IF Manager is reporting wrong frequencies after the PF_IF_Conditioner.
  • Setup problem was resolved.
    • The Fix for both of these problems:
      • In IF Manager set both IFConditioner_RF_relay-switchA and IFConditioner_RF_relay-switchB to have the value of 2 if the PF Support Rack RF_relay_switch is set to StandardPF.
      • IF the PF Support Rack RF_relay_switch is set to 1070MHz then the If Manager IFConditioner_RF_relay-switchA and IFConditioner_RF_relay-switchB values should be 1.

• 2. Check all the basic receiver controls:
  • Amplifier power switches.
  • Noise cal high/low and External/MCB switches.
  • Lnear/circular polarizations.
  • Tuning frequency and phase/attenuator settings for circular polarization.
  • IF bandpass filters.
    • 20 MHz filter on YRB does not let any power through.

• 3. Do a couple of pointing and focus scans on a strong calibrator
  • Could not perform these tests due to being at snow dump.

• 4. Do spectra of the whole band (900-1250 MHz).
  • Used config script in /home/astro-util/projects/PF1800/setup.py
  • Do on/offs in both linear and circular polarization.
    • Could not due full tests due to being at snow dump.
    • Do these on/offs on - can be 2 minute of/ 2 minutes off.
      • a)blank sky
      • b)weak calibrator
      • c)strong calibrator
    • These can all be used to
      • survey RFI
      • calibrate Tcals vs frequency
      • investigate linearity/non-linearity.
      • check that dish gets the right frequency axis
        • IARDS could not connect to glishd
        • IARDS did not have the correct frequency - related to the cabling file/ IF Manager problem.
        • After the If Manger - PF_Support Rack communications problem was initial fixed the IF Manager is still reporting incorrect frequencies in the spectrometer. IARDS is also showing incorrect frequencies.
        • After the IF Manger problem was fixed the frequencies were OK.

RFI

At times we would see some RFI that saturated the first amplifiers!
A plot of this is available here: http://wwwlocal.gb.nrao.edu/~tminter/rfi/PF800/05feb28-amp-saturated.ps

• rfi-low-raw.jpg:
  

• rfi-low-zoom.jpg:
  

• rfi-high-raw.jpg:
  

• rfi-high-zoom.jpg:
  

-- ToneyMinter - 28 Feb 2005

Attachment:	Action:	Size:	Date:	Who:	Comment:
rfi-low-raw.jpg	action	40865	28 Feb 2005 - 16:31	ToneyMinter
rfi-low-zoom.jpg	action	58324	28 Feb 2005 - 16:29	ToneyMinter
rfi-high-raw.jpg	action	39088	28 Feb 2005 - 16:31	ToneyMinter
rfi-high-zoom.jpg	action	56337	28 Feb 2005 - 16:33	ToneyMinter