Arecibo Observatory C-Band Receiver

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C-Band

Basic Information

Calibration & Beam Parameters

RFI Situation

Recent Events

Receiver History

Contact Info

1. Basic Information:

Frequency Range (GHz):	3.95 - 6.05 GHz*
Name and Number:	C-Band (cb, 9)
Measured Sensitivity (K/Jy):	7.0 - 9.0 (4.5 GHz) 6.0 - 8.5 (5.0 GHz) 5.5 - 8.0 (5.4 GHz) 5.0 - 7.5 (5.9 GHz)**
Measured System Temp (K):	25 - 31 (4.5 GHz) 25 - 30 (5.0 GHz) 27 - 32 (5.4 GHz) 26 - 31 (5.9 GHz)**
Native Polarization:	Dual Linear
Beam Size (at 5 GHz):	54 x 60 arcsec

*Although the bandpass of this receiver is over 2 GHz wide, currently only a 1-GHz wide chunk can be brought to the Control Room for processing at any given time.

**See calibration info below for a more accurate description of the telescope parameters! Note that these values depend upon the accuracy of the noise-diode calibration in estimating the system temperature and K/Jy. As well as both sensitivity and Trx being functions of zenith angle, the telescope sensitivity will also, at some level, be a function of azimuth. See calibration info below for a more accurate description of the telescope parameters!

Warnings & Important Notes: Resonances in the passband of the C-Band receiver occur at 4160.5, 5246.5, and 5676.5 MHz. Click here for more detailed information,

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2. Calibration & Beam Parameters:

Gain and Tsys

Cal Values

Beam Maps

Polarization

Misc. Info

Gain and Tsys
For detailed plots of the C-Band performance as a function of zenith angle back to 01 Sept. 2001, click here.
Cal Values
For detailed information on measured values for the C-Band calibration noise diode/s,
click here
Beam Maps
For detailed information on the magnitudes of C-Band coma-lobe and sidelobe levels, plus beam efficiencies, back to 01 Sept. 2001, click here
Polarization
While the native polarization of the receiver is linear, circular polarization can be produced using the 90-deg hybrid present in the 10-GHz IF chain. If this is required, consult your Local Friend.

BE WARNED that the calibration noise diodes should be used in "hcal" or "lcal" mode for circular polarization. The "cal steps" in degrees K that results for each channel is then the mean of the noise diode values measured for "hval" and "lcal" in linear polarization.
Misc. Info
To see an up-to-date plot of Tsys, just type tsys on your terminal after logging into Arecibo's computer network.

For detailed plots of the C-Band System Equivalent Flux Density (SEFD) and pointing performance back to 01 Sept. 2001, click here .

For the most recent focus curve for the C-Band receiver, click here .

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3. RFI situation:

As yet, C-band suffers relatively little from Radio Frequency Interference (RFI). 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 C-Band RFI plot from the Arecibo "hill-top" monitoring system, click here .
For the current frequency v time C-band RFI plot from the Arecibo "hill-top" monitoring system, click here .
For the current frequency v time C-band RFI plot (with band-pass correction) from the Arecibo "hill-top" monitoring system, click here .
For the current daily rms/mean v frequency C-band 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 C-Band link on this web page.

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4. Recent Events:

click here.

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5. Receiver History:

For a full history of the C-Band receiver, click here.

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6. Contact Info:

For further information on this receiver, please contact Chris Salter at
csalter (append @naic.edu)

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