1.9-cm primary focus receiver (13500-18700 MHz)

This is a 1-channel broad-band system used for spectroscopy. It has a linearly polarized feed. So far, only few test observations could be made to measure the variation of its parameters with frequency.

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
13.75 B linear 1.5 35 1.1 32 39 1.8 61 60.3 Mar 2001
15.42 B linear 1.7 37 1.2 32 41 1.8 64 53.5 Apr 2003
18.00 B linear 1.2 46 0.90 51 32 1.7 53 46.5 Mar 2001
normalized Gain curve (G = A0 + A1·Elv + A2·Elv2) Observed in confirmed
A0=0.95912A1= 2.5000E-3A2=-3.8149E-5Apr 2003

Comments:

  • The values at 15.4 GHz could be derived from cross-scans during spectroscopic observations. Thanks to N. Nagar!
  • Values at 18 GHz are a bit uncertain.

Version description for OBSINP

RX Name Wavelength [cm] Frequency (center) [GHz] Nr. of Horns
P19mm 4-Box (13.5-18.7 GHz) 2.2-1.6 13.5-18.7 1
Version: Comment
1. Cont./Line: 13,3-16,75 GHz (BW: 500 MHz) VLBA IF Continuum and spectroscopy version, 1st freq. range
2. Cont./Line: 16,55-18,5 GHz (BW: 500 MHz) VLBA IF Continuum and spectroscopy version, 2nd freq. range
3. Cont./Line: 13,5-16,95 GHz (BW: 100 MHz) narrow band IF Continuum and spectroscopy version, 1st freq. range
4. Cont./Line: 16,3-18,5 GHz (BW: 100 MHz) narrow band IF Continuum and spectroscopy version, 2nd freq. range
Horn offsets [arcsec] -904.0, 1077.4

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
optical: optical fibre with 4 GHz of band width
BW: band width
TP: total power

1.9cm PFK (Multi-RX-Box I)
Channel IF Pol. Comment
1 SB linear TP A
2 BB linear TP A
3 VLBA linear TP A

Spectroscopy modes and resolution

BW nchan nu Df Dv dv
MHz MHz kHz km/s km/s
100 32768 13500 3.1 0.068 0.079
100 32768 14000 3.1 0.065 0.076
100 32768 14500 3.1 0.063 0.073
100 32768 15000 3.1 0.061 0.071
100 32768 15500 3.1 0.059 0.068
100 32768 16000 3.1 0.057 0.066
100 32768 16500 3.1 0.055 0.064
100 32768 17000 3.1 0.054 0.062
100 32768 17500 3.1 0.052 0.061
100 32768 18000 3.1 0.051 0.059
100 32768 18500 3.1 0.049 0.057
500 32768 13500 15.3 0.339 0.393
500 32768 14000 15.3 0.327 0.379
500 32768 14500 15.3 0.315 0.366
500 32768 15000 15.3 0.305 0.354
500 32768 15500 15.3 0.295 0.342
500 32768 16000 15.3 0.286 0.332
500 32768 16500 15.3 0.277 0.322
500 32768 17000 15.3 0.269 0.312
500 32768 17500 15.3 0.261 0.303
500 32768 18000 15.3 0.254 0.295
500 32768 18500 15.3 0.247 0.287

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/p19mm.txt · Last modified: 2013/11/28 12:04 by bwinkel     Back to top