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 = 0.97323A1 = 1.2702E-3A2 = -1.5059E-5May 2004
A0 = 0.995A1 = 5.2022E-4A2 = -1.27874e-05Feb 2008

Comments:

  • The values for LCP and RCP do not differ significantly.
  • The new gain curve (Feb 2007) was corrected for opacity.
  • If no other information about the opacity is available a typical zenith tau value of about 0.016 should do a good job.

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/s60mm.txt · Last modified: 2014/12/17 13:35 by akraus     Back to top