====== 2.2cm/2.5cm prime focus receiver (12100-12280 MHz/12900-13600 MHz) ======

This is a 2-channel system used for spectroscopy. The 2.5cm part is realized by a new filter. The calibration parameters are still somewhat uncertain (about 10%). The lower part of the band at 12.1 GHz is affected by RFI from TV satellites which might also explain the higher Tsys.

==== Calibration Information ====

^ Frequency [GHz] ^ Channel ^ Polarisation ^ Tcal [K] ^ Tsys [K] ^ Sensitivity [K/Jy] ^ SEFD [Jy] ^ Aperture Eff. [%] ^ TMB/S [K/Jy] ^ Main Beam Eff. [%] ^ FWHM [arcsec] ^ Last update ^
|12.10 |A |LCP |6.5 |128 |1.4 |93 |48 |1.9 |71 |65.0 |Dec 2009  |
|12.10 |A |RCP |5.6 |210 |1.4 |155 |48 |1.9 |70 |65.0 |Dec 2009 |
|12.18 |A |LCP |5.2 |79 |1.4 |57 |47 |1.9 |75 |65.0 |Dec 2009	|
|12.18 |A |RCP |4.5 |102 |1.4 |78 |47 |1.9 |71 |65.0 |Dec 2009  |
|13.09 |A |LCP |2.0 |64 |1.45 |44 |51 |1.9 |78 |62.0 |Aug 2009  |
|13.09 |B |RCP |2.0 |65 |1.45 |45 |51 |1.9 |78 |62.0 |Aug 2009  |
|13.39 |A |LCP |1.8 |61 |1.4 |42 |50 |1.9 |74 |59.3 |Sep 2005	|
|13.39 |B |RCP |2.1 |63 |1.4 |44 |50 |1.9 |74 |59.3 |Sep 2005	|

^ normalized Gain curve (G = A0 + A1·Elv + A2·Elv2)^^^ Observed in ^ confirmed ^
|A0 = 0.9644|A1 = 2.1838E-03|A2 = -3.3018E-05|Dec 2009| |

**Comments:**
   * The values across the band and for LCP and RCP do not differ significantly in the 2.2cm band. 

==== Version description for OBSINP ====

^ RX Name ^ Wavelength [cm] ^ Frequency (center) [GHz] ^ Nr. of Horns ^
| **P22mm 4-Box (12,1- 13,6 GHz) ** | 2.2-2.5 | 12.1-13.6 (13.1) | 1 | 
| **Version:** |   **Comment**   |||
|1. Cont./Line: 12,1-12,25 GHz (2,5 cm) (BW: 100 MHz) | Continuum and spectroscopy at 2.5cm |||
|2. Cont./Line: 12,9-13,6 GHz (2,2 cm) (BW: 100 MHz) | Continuum and spectroscopy at 2.2cm  |||
| **Horn offsets** [arcsec]| -1155.5, 1066.7 |||


==== Channel assignment in the MBFITS data files ====

Note that the narrow line and VLBA IF channels are usually only available when the specific line version of the receiver was selected. In addition for most receivers with narrow line channels the cables at the patch board need to be connected by the receiver group.

To select different channel numbers in OBSINP, the online plot, or the toolbox the numbers have to be specified like c(1)+c(2) to add channel 1 and 2. E.g. channel 1 and 2 contain the LCP and RCP broadband channels, then "OnlPlot pen='c(1)+c(2)'" or "toolbox use='c(1)+c(2)'" will select these channels. In OBSINP the pen can be directly specified in the receiver selection menu.

Abbreviations:\\
SB: narrow band channel (Schmalband-Kanal), 100 MHz band width\\
BB: digital broad band channel (Breitband-Kanal), band width varies for different receivers\\
VLBA: VLBA IF, 500 MHz band width\\
BW: band width\\
TP: total power

^ 2.2cm/2.5cm PFK (Multi-RX-Box II) ^^^^
^ Channel ^ IF ^ Pol. ^ Comment ^
|  1  |  SB    |     LCP    | 2.2cm, TP A  |
|  2  |  SB    |     RCP    | 2.2cm, TP B  |
|  3  |  SB    |     cross  | 2.2cm, cos AB   |
|  4  |  SB    |     cross  | 2.2cm, sin AB   |
|  5  |   SB    |     LCP   | 2.5cm, TP A  |
|  6  |   SB    |     RCP   | 2.5cm, TP B  |

==== Spectroscopy modes and resolution ====
^   BW ^ nchan ^    nu ^     Df ^     Dv ^     dv ^
^  MHz ^       ^   MHz ^    kHz ^   km/s ^   km/s ^
|  100 | 32768 | 12100 |    3.1 |  0.076 |  0.088 |
|  100 | 32768 | 12150 |    3.1 |  0.075 |  0.087 |
|  100 | 32768 | 12200 |    3.1 |  0.075 |  0.087 |
|  100 | 32768 | 12250 |    3.1 |  0.075 |  0.087 |
|  100 | 32768 | 12900 |    3.1 |  0.071 |  0.082 |
|  100 | 32768 | 13000 |    3.1 |  0.070 |  0.082 |
|  100 | 32768 | 13100 |    3.1 |  0.070 |  0.081 |
|  100 | 32768 | 13200 |    3.1 |  0.069 |  0.080 |
|  100 | 32768 | 13300 |    3.1 |  0.069 |  0.080 |
|  100 | 32768 | 13400 |    3.1 |  0.068 |  0.079 |
|  100 | 32768 | 13500 |    3.1 |  0.068 |  0.079 |
|  100 | 32768 | 13600 |    3.1 |  0.067 |  0.078 |

BW    ... band width\\
nchan ... number of spectral channels\\
nu    ... center frequency\\
Df    ... Channel separation (in frequency)\\
Dv    ... Channel separation (in velocity)\\
dv    ... Velocity resolution (dv=1.16*Dv)

==== Tcal and Tsys measurements ====

TODO