====== 2cm double beam secondary focus receiver (12000-18000 MHz) ======

This receiver replaced the old 2cm secondary focus system. It is a two horn system for continuum, spectroscopy and VLBI observations. The system is currently tested and all values are preliminary. \\
**Note, that for technical reasons, no spectroscopic frequency-switch observations are possible!**

==== Calibration Information ====

^ Frequency [GHz] ^ Feed ^ Polarisation ^ Tcal [K] ^ Tsys [K] ^ Sensitivity [K/Jy] ^ SEFD [Jy] ^ Aperture Eff. [%] ^ TMB/S [K/Jy] ^ Main Beam Eff. [%] ^ FWHM [arcsec] ^ Last update ^
| 13.0 | 1 | LCP | 4.2 | 55 | 1.42 | 77 | 50 | 2.13 | 66 | 58.3 | Nov 2019 |
| 13.0 | 1 | RCP | 4.5 | 55 | 1.42 | 78 | 50 | 2.14 | 66 | 58.3 | Nov 2019 |
| 15.0 | 1 | LCP | 2.5 | 59 | 1.31 | 77 | 46 | 1.97 | 66 | 52.7 | Nov 2019 |
| 15.0 | 1 | RCP | 2.4 | 61 | 1.30 | 80 | 46 | 1.96 | 66 | 52.5 | Nov 2019 |
| 17.0 | 1 | LCP | 4.1 | 64 | 1.19 | 76 | 42 | 1.80 | 66 | 48.4 | Nov 2019 |
| 17.0 | 1 | RCP | 4.5 | 65 | 1.17 | 76 | 41 | 1.79 | 66 | 48.6 | Nov 2019 |
 

^ normalized Gain curve (G = A0 + A1·Elv + A2·Elv2)^^^ Observed in ^ confirmed ^
|A0 = 0.97099 |A1 = 1.8327E-3 |A2 = -2.8674E-5 | (from old S20mm) | ---  |


**Comments:**
   * Note that the system temperature at this frequency depends strongly on weather conditions! 
   * Zenith tau values can range from ??? to ???. 

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

^ RX Name ^ Wavelength [cm] ^ Frequency (center) [GHz] ^ Nr. of Horns ^
| **S20mm Double Beam RX ** | 2.0 | 12.0-18.0 (15.0) | 2 | 
| **Version:** |   **Comment**   |||
|1. Continuum (BW: 2 GHz) | Broad Band Continuum |||
| **Horn offsets** (Azi, Elv, from center of SFK)| Horn 1: -525" ; 63" -- Horn 2: -762" ; 63" |||
|relative offset of horn 2 from 1 (Azi, Elv)| -237" ; 0"|||


==== Receiver Bands ====

The receiver delivers the data in two 2.5GHz-wide IF-subbands, which can be shifted in to cover the 12-18 GHz range.

==== Spectroscopy modes and resolution ====
=== Low-res mode (2 basebands for each of 2 feeds and 2 polarizations) ===
**Note, that due to technical reasons the LSR correction has to be applied via software (regridding). This will decrease the effective spectral resolution to some degree.**


**TODO: update numbers!**

^   BW ^ nchan ^    nu ^     Df ^     Dv ^     dv ^
^  MHz ^       ^   MHz ^    kHz ^   km/s ^   km/s ^
| 2500 | 16384 | 18000 |  152.6 |  2.541 |  2.948 |
| 2500 | 16384 | 20000 |  152.6 |  2.287 |  2.653 |
| 2500 | 16384 | 22000 |  152.6 |  2.079 |  2.412 |
| 2500 | 16384 | 24000 |  152.6 |  1.906 |  2.211 |
| 2500 | 16384 | 26000 |  152.6 |  1.759 |  2.041 |
| 2500 | 32768 | 18000 |   76.3 |  1.271 |  1.474 |
| 2500 | 32768 | 20000 |   76.3 |  1.144 |  1.327 |
| 2500 | 32768 | 22000 |   76.3 |  1.040 |  1.206 |
| 2500 | 32768 | 24000 |   76.3 |  0.953 |  1.105 |
| 2500 | 32768 | 26000 |   76.3 |  0.880 |  1.020 |
| 2500 | 65536 | 18000 |   38.1 |  0.635 |  0.737 |
| 2500 | 65536 | 20000 |   38.1 |  0.572 |  0.663 |
| 2500 | 65536 | 22000 |   38.1 |  0.520 |  0.603 |
| 2500 | 65536 | 24000 |   38.1 |  0.477 |  0.553 |
| 2500 | 65536 | 26000 |   38.1 |  0.440 |  0.510 |
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)


=== Hi-res mode (?? basebands) ===

**TODO: update numbers!**
^   BW ^ nchan ^    nu ^     Df ^     Dv ^     dv ^
^  MHz ^       ^   MHz ^    kHz ^   km/s ^   km/s ^
|  300 | 16384 | 18000 |   18.3 |  0.305 |  0.354 |
|  300 | 16384 | 20000 |   18.3 |  0.274 |  0.318 |
|  300 | 16384 | 22000 |   18.3 |  0.250 |  0.289 |
|  300 | 16384 | 24000 |   18.3 |  0.229 |  0.265 |
|  300 | 16384 | 26000 |   18.3 |  0.211 |  0.245 |
|  300 | 32768 | 18000 |    9.2 |  0.152 |  0.177 |
|  300 | 32768 | 20000 |    9.2 |  0.137 |  0.159 |
|  300 | 32768 | 22000 |    9.2 |  0.125 |  0.145 |
|  300 | 32768 | 24000 |    9.2 |  0.114 |  0.133 |
|  300 | 32768 | 26000 |    9.2 |  0.106 |  0.122 |
|  300 | 65536 | 18000 |    4.6 |  0.076 |  0.088 |
|  300 | 65536 | 20000 |    4.6 |  0.069 |  0.080 |
|  300 | 65536 | 22000 |    4.6 |  0.062 |  0.072 |
|  300 | 65536 | 24000 |    4.6 |  0.057 |  0.066 |
|  300 | 65536 | 26000 |    4.6 |  0.053 |  0.061 |

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 measurements ====
=== Mar 2020 ===
== Tcal and Tsys ==
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_tcal_from_specpointing_using_tau_spec.png?365 |}}
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_tsys0_from_specpointing_using_tau_spec.png?365 |}}

== Opacity and Tebb (WVR+AATM) ==
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_tau_from_specpointing_using_tau_spec.png?365 |}}
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_tebb_from_specpointing_using_tau_spec.png?365 |}}

== T0 ==
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_t0_from_specpointing_using_tau_spec.png?365 |}}

== Antenna model ==
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_taper_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_hpbw_from_specpointing.png?365 |}}

{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_gamma_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_gammamb_from_specpointing.png?365 |}}

{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_eta_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:effbg_s20mm_kuband_2020mar27_ngc7027_wrv_etamb_from_specpointing.png?365 |}}

=== Nov 2019 ===
== Tcal and Tsys ==
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_tcal_from_specpointing_using_tau_spec.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_tcal_from_specpointing_using_tau_spec.png?365 |}}\\
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_tsys0_from_specpointing_using_tau_spec.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_tsys0_from_specpointing_using_tau_spec.png?365 |}}

== Opacity and Tebb (WVR+AATM) ==
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_tau_from_specpointing_using_tau_spec.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_tau_from_specpointing_using_tau_spec.png?365 |}}\\
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_tebb_from_specpointing_using_tau_spec.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_tebb_from_specpointing_using_tau_spec.png?365 |}}

== T0 ==
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_t0_from_specpointing_using_tau_spec.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_t0_from_specpointing_using_tau_spec.png?365 |}}

== Antenna model ==
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_taper_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_taper_from_specpointing.png?365 |}}\\
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_hpbw_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_hpbw_from_specpointing.png?365 |}}

{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_gamma_from_specpointing.png?365 |}}\\
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_gamma_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_gammamb_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_gammamb_from_specpointing.png?365 |}}

{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_eta_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_eta_from_specpointing.png?365 |}}\\
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_L_etamb_from_specpointing.png?365 |}}
{{:information_for_astronomers:rx:EFFBG_S20mm_Cband_2019Nov22_3C286_aatm_R_etamb_from_specpointing.png?365 |}}