3.6cm secondary focus receiver (7800-8900 MHz)

This is a 4-channel system mainly for sensitive continuum observations, polarimetry, VLBI and pulsar observations. Simultaneous operation with the S-band (13cm, 2.2 GHz) receiver for geo VLBI observations are possible.

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
8.410 I (BB) RCP 2.5 22 1.35 18 45 2.6 49 81.7 Jul 2008
8.410 J (BB) LCP 2.5 22 1.35 18 45 2.6 49 81.7 Jul 2008
8.550 I (BB) RCP 2.5 23 1.35 18 46 2.6 50 80.6 Jul 2008
8.550 J (BB) LCP 2.5 25 1.35 19 46 2.6 50 80.6 Jul 2008
normalized Gain curve (G = A0 + A1·Elv + A2·Elv2) Observed in confirmed
A0 = 0.97453A1 = 1.192E-3A2 = -1.389E-5Dec 2001
A0 = 0.99500A1 = 4.3434e-04A2 = -1.0562e-05Feb 2007

Comments:

  • All values are valid for the new receiver which was installed in September 2001. If you need data for the old one, please contact akraus_at_mpifr-bonn.mpg.de.
  • Note that (against our usual designation) Channel A is RCP and B LCP!
  • 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 0.018 should do a good job.

Version description for OBSINP

RX Name Wavelength [cm] Frequency (center) [GHz] Nr. of Horns
S36mm + 13cm 3.6/13 7.9-9.0 (8.35)/2.4 1
Version: Comment
1. Continuum (BW: 1.1 GHz) Broad Band Continuum + Polarimeter
2. Line (BW: 100 MHz) Spectroscopy/Continuum using narrow band IF + VLBI IF Polarimeter
3. Line (BW: 500 MHz) Spectroscopy/Continuum using VLBA IF + VLBA IF Polarimeter
4. Pulsar (BW: 1.1 GHz) Pulsar 1.1 GHz BW Version
5. Pulsar (BW: 500 MHz) Pulsar 500 MHz BW Version
6. Pulsar (BW: 100 MHz) Pulsar 100 MHz BW Version

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

3.6cm SFK single horn receiver with polarimeter (+13cm offset horn for Geo-VLBI)
Channel IF Pol. Comment
1 SB RCP TP A
2 SB LCP TP B
3 SB cross cos AB
4 SB cross sin AB
5 SB RCP 13cm, TP A
6 BB LCP TP A
7 BB RCP TP B
8 BB cross cos AB
9 BB cross sin AB
10 VLBA LCP TP A
11 VLBA RCP TP B
12 VLBA cross cos AB
13 VLBA cross sin AB

Spectroscopy modes and resolution

BW nchan nu Df Dv dv
MHz MHz kHz km/s km/s
100 32768 7800 3.1 0.117 0.136
100 32768 8000 3.1 0.114 0.133
100 32768 8200 3.1 0.112 0.129
100 32768 8400 3.1 0.109 0.126
100 32768 8600 3.1 0.106 0.123
100 32768 8800 3.1 0.104 0.121
500 32768 7800 15.3 0.586 0.680
500 32768 8000 15.3 0.572 0.663
500 32768 8200 15.3 0.558 0.647
500 32768 8400 15.3 0.545 0.632
500 32768 8600 15.3 0.532 0.617
500 32768 8800 15.3 0.520 0.603

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/s36mm.txt · Last modified: 2013/11/20 15:48 by bwinkel     Back to top