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 = 0.8806A1 = 5.8673E-3A2 = -7.1243E-05Dec 2007
A0 = 0.8800 A1 = 6.9970E-3A2 = -1.0210E-04Mar 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

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

 
information_for_astronomers/rx/s7mm.txt · Last modified: 2016/05/12 09:57 by ubach     Back to top