APPENDIX: GBT Prime Focus Receivers

Receiver Center f(GHz) Fsky (GHz) waveLen(cm) FWHM est.Tsys IF1 (GHz)
PF1.1 0.3425 0.290 - 0.395 88 36' 30 K 1.080
PF1.2 0.450 0.385 - 0.520 66 27' 30 K 1.080
PF1.3 0.600 0.510 - 0.690 50 21' 30 K 1.080
PF1.4 0.800 0.680 - 0.920 37 15' 25 K 1.080
PF2 1.070 0.910 - 1.230 28 12' 25 K 1.500


Calibration data may be viewed by clicking in the "Receiver" column.

All prime focus receivers have one beam and two polarizations. Either dual linear or dual circular polarizations may be selected.

Note that when the PF focus-rotation mount is oriented at +/- 90 degrees, the X-channel is horizontal polarization and the Y-channel is vertical polarization.

The first stages of the receivers are cooled FET amplifiers. The feeds for bands 1-3 (0.290-0.690 GHz) are short-backfire dipoles. The feeds for bands 4 and 5 (0.68-0.92 and 0.91-1.23 GHz) are corrugated feed horns with orthomode transducers (OMT) to split the polarizations. The OMTs have certain resonant frequencies creating spikes in the response that may show up as emission features, or absorption features on continuum sources. For band 4, the approximate resonant frequencies are: 797 and 818 MHz. For band 5, the approximate resonant frequencies are: 922, 1056, and 1174 MHz.

Receiver Changes:

IF conversion:


First LO setting (LO1) :
LO1 range for PF1 :
Filters:
Attenuators:

PF1.1: Prime Focus Receiver 1.1 (290-395 MHz)


Calibration data.

PF_1 Feed:340 calibration data

PF1.2: Prime Focus Receiver 1.2 (385-520 MHz)


Calibration data 

PF_1 Feed:450 calibration data

PF1.3: Receiver 1.3 (510-690 MHz)


Calibration data.

PF_1 Feed:600 calibration data.

PF1.4: Prime Focus Receiver 1.4 (680-920 MHz)


Calibration data.

PF_1 Feed:800 calibration data.

PF2: Prime Focus Receiver 2 (910-1230 MHz)


Calibration data. 

Prime Focus Receiver 2 calibration.