2. Calibration & Beam Parameters:
| Gain and Tsys | Cal Values | Beam Maps | Polarization | Misc. Info |
- Gain and Tsys
For detailed plots of the 610-MHz receiver performance as a function of zenith angle back to 01 May, 2001, click here.- Cal Values
Only a single noise diode with a single intensity is available for this receiver. This is denoted as "lcorcal", and gives measured temperature steps of 42.49 K in Polarization A, and 41.09 in Polarization B for linear polarization.
- Beam Maps
For detailed information on the magnitudes of the coma-lobe and sidelobe levels at 610 MHz, plus beam efficiencies, back to 01 May, 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 as there is only a "correlated" calibration from the noise diode available with this receiver, the "cal step" that results when using circular polarization with this receiver is effectively unknown in degrees K.- 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 610-MHz System Equivalent Flux Density (SEFD) and pointing performance back to 01 May, 2001, click here .
- Cal Values
The 610-MHz band is a protected band for radio astronomy between 608 and 614 MHz, (i.e. the purposely-vacant T.V. Channel 37). However, at Arecibo this band has historically suffered extreme RFI from out-of-band emissions originating from a nearby (spatially and in frequency) TV station. This is why the present relatively narrow-band filter is in the system at 610 MHz. It is hoped to obtain a wider-band filter in the near future to cover at least the complete protected band.
A recent spectrum showing the presence of RFI at 607.78 (mostly in Poln. A), 608.56 (Poln. B only), and 609.25 MHz, also illustrates the present pass-bands for the two polarization in native linear mode.
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 610-MHz RFI plot from the Arecibo
"hill-top" monitoring system, click here .
- For the current frequency v time 610-MHz RFI plot
from the Arecibo
"hill-top" monitoring system, click here .
- For the current frequency v time 610-MHz RFI plot (with band-pass
correction)
from the Arecibo
"hill-top" monitoring system, click here .
- For the current daily rms/mean v frequency 610-MHz RFI plot
from the Arecibo
"hill-top" monitoring system, click here .
The 710-MHz band is only usable between MIDNIGHT and 6 AM. During that time, in accordance with a local agreement, TV Channel 54 at 711 MHz switches off.
-
For the most recent history of the 610-MHz receiver,
click here.
For a full history of the 610-MHz receiver, click here.
For further information on this receiver, please contact Chris Salter at
csalter (append @naic.edu)