====== 13cm secondary focus receiver (2200-2300 MHz) ======

This receiver was constructed for S/X VLBI observations together with the 3.6cm system. It is a single channel system (RCP) illuminated by a paraboloid mirror (with a central opening) which is built around the 3.6cm horn. There is no S130mm receiver version, but the S-band signal is available as a 5th channel of the S36mm X-band receiver (see this {{information_for_astronomers:rx:sfk.png?linkonly|picture}}).

==== 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 ^
|2.250| A |RCP |13.6 |150 |0.49 |306 |17 | | |354 |Dez 2004 |

^ normalized Gain curve (G = A0 + A1·Elv + A2·Elv2)^^^ Observed in ^ confirmed ^
|A0 = 1.0|A1 = 0.0|A2 = 0.0|Feb 2007| |

**Comments:**
   * The special configuration (tertiary mirror) leads to an additional loss of sensitivity. 

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

^ RX Name ^ Wavelength [cm] ^ Frequency (center) [GHz] ^ Nr. of Horns ^
| **S36mm + 13cm** | 3.6/13 | 7.9-9.0 (8.35)/2.4 | 1 | 
| **Version:** |   **Comment**   |||
|1. Continuum (BW: 1.1 GHz) | Broad Band Continuum + Polarimeter |||
|2. Line (BW: 100 MHz) | Spectroscopy/Continuum using narrow band IF + VLBI IF Polarimeter|||
|3. Line (BW: 500 MHz) | Spectroscopy/Continuum using VLBA IF + VLBA IF Polarimeter |||
|4. Pulsar (BW: 1.1 GHz) | Pulsar 1.1 GHz BW Version |||
|5. Pulsar (BW: 500 MHz) | Pulsar 500 MHz BW Version |||
|6. Pulsar (BW: 100 MHz) | Pulsar 100 MHz BW Version |||



==== 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

^ 3.6cm SFK single horn receiver with polarimeter (+13cm offset horn for Geo-VLBI) ^^^^
^ Channel ^ IF ^ Pol. ^ Comment ^
|  1  |    SB     |     RCP    | TP A  |
|  2  |    SB     |     LCP    | TP B  |
|  3  |    SB     |    cross   | cos AB  |
|  4  |    SB     |    cross   | sin AB  |
|  **5**  |    **SB**     |     **RCP**    | **13cm, TP A**  |
|  6  |    BB     |     LCP    | TP A  |
|  7  |    BB     |     RCP    | TP B  |
|  8  |    BB     |    cross   | cos AB  |
|  9  |    BB     |    cross   | sin AB  |
|  10  |   VLBA	 |    LCP    | TP A  |
|  11  |   VLBA	 |    RCP    | TP B  |
|  12  |   VLBA	 |   cross   | cos AB  |
|  13  |   VLBA	 |   cross   | sin AB  |

==== Spectroscopy modes and resolution ====
^   BW ^ nchan ^    nu ^     Df ^     Dv ^     dv ^
^  MHz ^       ^   MHz ^    kHz ^   km/s ^   km/s ^
|  100 | 32768 |  2200 |    3.1 |  0.416 |  0.482 |
|  100 | 32768 |  2250 |    3.1 |  0.407 |  0.472 |
|  100 | 32768 |  2300 |    3.1 |  0.398 |  0.461 |
|  500 | 32768 |  2200 |   15.3 |  2.079 |  2.412 |
|  500 | 32768 |  2250 |   15.3 |  2.033 |  2.358 |
|  500 | 32768 |  2300 |   15.3 |  1.989 |  2.307 |

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 ====