====== 7mm secondary focus receiver (41600-44400 MHz) ======

 This is a 2-channel system for VLBI observations. The whole receiver was reconditioned in late 2012.\\
A new double-horn system is under construction. It should become operational in 2016.

==== 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 ^
|42.0 |A |LCP |13.8 |108 |0.53 |196 |19 |1.5 |36 |19.8 |Mar 2009 |
|42.0 |B |RCP |12.2 |131 |0.53 |248 |19 |1.5 |35 |19.8 |Mar 2009 |

^ normalized Gain curve (G = A0 + A1·Elv + A2·Elv2)^^^ Observed in ^ confirmed ^
|A0 = 0.8806|A1 = 5.8673E-3|A2 = -7.1243E-05|Dec 2007| |
|A0 = 0.8800 |A1 = 6.9970E-3|A2 = -1.0210E-04|Mar 2009| |

**Comments:**
   * The new gain curves were corrected for opacity.
   * Opacity correction was done with a zenith opacity of 0.08. Typical zenith opacities under good weather conditions are around 0.07 to 0.1 at 42 GHz. 
   * For informations about the old parameters please contact Uwe Bach (ubach_at_mpifr.de).

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

^ RX Name ^ Wavelength [cm] ^ Frequency (center) [GHz] ^ Nr. of Horns ^
| **S7mm Multifrequency RX ** | 0.7 | 41.6-44.4 (42.9) | 1 | 
| **Version:** |   **Comment**   |||
|1. Continuum (BW: 2 GHz) | Broad Band Continuum |||
|2. Line (BW: 500 MHz) | Spectroscopy/Continuum using VLBA IF + VLBA IF Polarimeter |||
|3. Pulsar (BW: 500 MHz) | Pulsar 500 MHz BW Version |||
| **Horn offsets** [arcsec]| -466.2,58.6 |||


==== 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


^ 7mm SFK single horn receiver ^^^^
^ Channel ^ IF ^ Pol. ^ Comment ^
|  1  |    SB     |     LCP    | TP A  |
|  2  |    SB     |     RCP    | TP B  |
|  3  |    SB     |     cross  | cos AB  |
|  4  |    SB     |     cross  | sin AB  |
|  5  |   VLBA    |     LCP   | TP A  |
|  6  |   VLBA    |     RCP   | TP B  |
|  7  |   VLBA    |    cross  | cos AB  |
|  8  |   VLBA    |    cross  | sin AB  |
|  9  |    BB    |     LCP   | TP A  |
|  10  |   BB    |     RCP    | TP B  |

==== Spectroscopy modes and resolution ====
^   BW ^ nchan ^    nu ^     Df ^     Dv ^     dv ^
^  MHz ^       ^   MHz ^    kHz ^   km/s ^   km/s ^
|  100 | 32768 | 41500 |    3.1 |  0.022 |  0.026 |
|  100 | 32768 | 42500 |    3.1 |  0.022 |  0.025 |
|  100 | 32768 | 43500 |    3.1 |  0.021 |  0.024 |
|  100 | 32768 | 44500 |    3.1 |  0.021 |  0.024 |
|  500 | 32768 | 41500 |   15.3 |  0.110 |  0.128 |
|  500 | 32768 | 42500 |   15.3 |  0.108 |  0.125 |
|  500 | 32768 | 43500 |   15.3 |  0.105 |  0.122 |
|  500 | 32768 | 44500 |   15.3 |  0.103 |  0.119 |

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:s7mm_2015aug7_ngc7027_aatm_tsys0_from_specpointing_using_tau_spec.png?675|}}

{{:information_for_astronomers:rx:s7mm_2015aug7_ngc7027_aatm_tcal_from_specpointing_using_tau_spec.png?675|}}

{{:information_for_astronomers:rx:s7mm_2015aug7_ngc7027_aatm_tau_from_specpointing_using_tau_spec.png?675|}}

{{:information_for_astronomers:rx:s7mm_2015aug7_ngc7027_aatm_hpbw_from_specpointing.png?350|}}
{{:information_for_astronomers:rx:s7mm_2015aug7_ngc7027_aatm_taper_from_specpointing.png?350|}}

{{:information_for_astronomers:rx:s7mm_2015aug7_ngc7027_aatm_eta_from_specpointing.png?350|}}
{{:information_for_astronomers:rx:s7mm_2015aug7_ngc7027_aatm_etamb_from_specpointing.png?350|}}

{{:information_for_astronomers:rx:s7mm_2015aug7_ngc7027_aatm_gamma_from_specpointing.png?350|}}
{{:information_for_astronomers:rx:s7mm_2015aug7_ngc7027_aatm_gammamb_from_specpointing.png?350|}}

(No correction for angular size of NGC7027 was applied!)