Prime Focus 1 (PF1) receiver
----------------------------

The PF1 (0.29 - 0.92 GHz) receiver is divided into 4 frequency bands within the same receiver box.
The frequency ranges are 290-395 MHz, 385-520 MHz, 510-690 MHz, and 680-920 MHz.

The receivers are cooled Field Effect Transistor (FET) amplifiers. The feeds for the lower three bands are short-backfire dipoles, and the feed for the fourth (680-920 MHz) is a corrugated feed horn with an Ortho-Mode Transducer (OMT) polarization splitter. A feed change, required to switch between bands, takes 2-4 hours and must occur on a scheduled maintenance day.

The user can select one of four IF filters in the PF1 receiver. These have bandwidths of 20, 40, 80, 240 MHz.


.. note:: 

   The 450 MHz (385-520 MHz) and 600 MHz (510-690 MHz) PF1 feeds are unlikely to be considered for installation on the GBT.



PF450 and PF600 RFI
^^^^^^^^^^^^^^^^^^^

Digital TV signals at frequencies from 470 to 700 MHz will make observing very difficult with these receivers. Available RFI plots do not show the strength of these signals very well as they overpower the system. Please consult the GBO support scientists through the NRAO helpdesk before submitting a proposal for these feeds.