327-MHz Gregorian
Basic Information

Calibration & Beam Parameters

RFI Situation

Recent Events

Receiver History

Contact Info

 

 

 

1. Basic Information:

 

Frequency Range (GHz): 0.302 - 0.352

Name and Number:

327-MHz Gregorian (P Band)
Measured Sensitivity (K/Jy): 10*
Measured System Temp (K): 110-135*
Native Polarization: Dual linear
Beam Size (at 0.327 GHz): 14' x 15'
Available Filters: 50 MHz (302 - 352 MHz)
30 MHz (312 - 342 MHz)
Plot of frequency response with the 30 MHz filter can be found here
Warnings and Important Notes: click here

*See calibration info below for a more accurate description of the telescope parameters!

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2. Calibration & Beam Parameters:


Gain and Tsys Cal Values Beam Maps Polarization Misc. Info


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3. RFI situation:

The P band is now quite clean, specially at night, compared to the 10-MHz band centered at 430 MHz. There was previously a 2-MHz comb originating in the radar system, this has been dealt with successfuly, the comb is still detectable, but very weak.

During my preliminary observations with this receiver I have seen very strong interference at 307 MHz. This is already outside the nominal bandpass, but even with more than 20 dB of attenuation, this line can completely saturate the system. In such situations, one should increase the central (sky) frequency, or, if observing with the WAPP, use a filter with 25 MHz or less of bandwidth.

This is an UNIDENTIFIED radio FREQUENCY INTERFERENCE. For RFI with known identifications, click here.

Daily RFI monitoring plots for the past several years from the Observatory "hill-top" monitoring system can be found in binders in either the telescope Control Room or by asking the Arecibo Spectrum Manager.

  • For the current daily average 327-MHz RFI plot from the Arecibo "hill-top" monitoring system, click here .

  • For the current frequency v time 327-MHz RFI plot from the Arecibo "hill-top" monitoring system, click here .

  • For the current frequency v time 327-MHz RFI plot (with band-pass correction) from the Arecibo "hill-top" monitoring system, click here .

  • For the current daily rms/mean v frequency 327-MHz RFI plot from the Arecibo "hill-top" monitoring system, click here .

The occurrence of RFI versus frequency by month and year since Jan 2001 can be found via the 327 link on this web page.

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4. Recent Events:

    Link to electronics department containing updated receiver log

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5. Receiver History:

July 2002: Room temperature receiver installed.

The 327 receiver had been removed in 2001 to be worked on. It was re-installed in July 2002 with a room temperature receiver. The initial plan was to make it a cooled receiver, however leaks in the cryogenic dewar used to cool the receiver's LNA's have made that impossible. The current plan calls for the installation of a new receiver.

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6. Contact Info:

For further information on this receiver, please contact Julia Deneva
deneva (append @naic.edu)

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