====== 6-cm secondary focus receiver (4600-5100 MHz) ======

This is a 4-channel 2-horn system for sensitive continuum, polarimetry, VLBI, and pulsar observations. 

==== 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 ^
|4.850 |A / B |LCP / RCP |1.8 |27 |1.55 |18 |53 |2.4 |63 |146 |June 2008|

^ normalized Gain curve (G = A0 + A1·Elv + A2·Elv2)^^^ Observed in ^ confirmed ^
|A0 = 0.9870|A1 = 8.692E-4|A2 = -1.453E-5|Aug 2023|  |

**Comments:**
  * The values for LCP and RCP do not differ significantly.
  * The opacity is usually very small. Typical zenith tau values are < 0.01.

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

^ RX Name ^ Wavelength [cm] ^ Frequency (center) [GHz] ^ Nr. of Horns ^
| **S60mm Double Beam** | 6 | 4.6-5.1 (4.85) | 2 | 
| **Version:** |   **Comment**   |||
|1. Continuum (BW: 500 MHz) | Broad Band Continuum + Polarimeter |||
|2. Pulsar (BW: 500 MHz) | Pulsar 500 MHz Version |||
|3. Line (BW: 100 MHz) | Spectroscopy/Continuum using narrow band IF + VLBI IF Polarimeter|||
|4. Line (BW: 500 MHz) | Spectroscopy/Continuum using VLBA IF + VLBA IF Polarimeter |||
|5. Pulsar+8dB(BW: 500 MHz) | Pulsar with attenuation |||
| **Horn offsets** [arcsec]| Horn 1: 236.6,-1336.0, Horn 2: -248.4,-1336.0 |||


==== 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

^ 6cm SFK multi horn receiver with polarimeter, 2 horns ^^^^
^ Channel ^ IF ^ Pol. ^ Comment ^
|  1   |    SB     |     LCP    | Horn 1, TP A  |
|  2   |    SB     |     RCP    | Horn 1, TP B  |
|  3   |    SB     |    cross   | Horn 1, cos AB  |
|  4   |    SB     |    cross   | Horn 1, sin AB  |
|  5   |    BB     |     LCP    | Horn 1, TP A  |
|  6   |    BB     |     RCP    | Horn 1, TP B  |
|  7   |    BB     |    cross   | Horn 1, cos AB  |
|  8   |    BB     |    cross   | Horn 1, sin AB  |
|  9   |    BB     |     LCP    | Horn 2, TP A  |
|  10  |    BB	 |     RCP    | Horn 2, TP B  |
|  11  |    BB	 |    cross   | Horn 2, cos AB  |
|  12  |    BB	 |    cross   | Horn 2, sin AB  |
|  13  |   VLBA	 |    LCP    | Horn 1, TP A  |
|  14  |   VLBA	 |    RCP    | Horn 1, TP B  |
|  15  |   VLBA	 |   cross   | Horn 1, cos AB  |
|  16  |   VLBA	 |   cross   | Horn 1, sin AB  |

==== Spectroscopy modes and resolution ====
^   BW ^ nchan ^    nu ^     Df ^     Dv ^     dv ^
^  MHz ^       ^   MHz ^    kHz ^   km/s ^   km/s ^
|  100 | 32768 |  4600 |    3.1 |  0.199 |  0.231 |
|  100 | 32768 |  4700 |    3.1 |  0.195 |  0.226 |
|  100 | 32768 |  4800 |    3.1 |  0.191 |  0.221 |
|  100 | 32768 |  4900 |    3.1 |  0.187 |  0.217 |
|  100 | 32768 |  5000 |    3.1 |  0.183 |  0.212 |
|  100 | 32768 |  5100 |    3.1 |  0.179 |  0.208 |
|  500 | 32768 |  4600 |   15.3 |  0.994 |  1.154 |
|  500 | 32768 |  4700 |   15.3 |  0.973 |  1.129 |
|  500 | 32768 |  4800 |   15.3 |  0.953 |  1.105 |
|  500 | 32768 |  4900 |   15.3 |  0.934 |  1.083 |
|  500 | 32768 |  5000 |   15.3 |  0.915 |  1.061 |
|  500 | 32768 |  5100 |   15.3 |  0.897 |  1.040 |

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 ====
{{:information_for_astronomers:rx:s60mmb_tcal_from_specpointing_using_tau_spec.png?675 |}}
{{:information_for_astronomers:rx:s60mmb_tsys0_from_specpointing_using_tau_spec.png?675 |}}
{{:information_for_astronomers:rx:s60mmb_tau_from_specpointing_using_tau_spec.png?675 |}}
{{:information_for_astronomers:rx:s60mmb_hpbw_from_specpointing.png?675 |}}