Page 1 of 1

System temperature issues with CABB zoom configurations

PostPosted: Thu May 29, 2014 12:02 pm
by ste616
It has been apparent for some time that CABB configurations that offer bands other than the two 2048 MHz continuum IFs with 1 MHz resolution do not properly measure the system temperature online. This post aims to summarise the state of the CABB modes with respect to the system temperature capability.

1 MHz resolution, continuum only
Online system temperature calculation works as expected, in both IFs and for all bands.

Pulsar binning mode (two 1 MHz resolution continuum IFs, two 4 MHz resolution continuum binned IFs)
Online system temperature calculation works as expected for 1 MHz continuum IF1, but it does not work at all for the 1 MHz continuum IF2.

1 MHz resolution continuum plus 16 zooms in each IF (the 1 MHz zoom mode)
Online system temperature calculation works as expected for both IFs, in each band except for 3mm. At 3mm, where the paddle is used to calculate the system temperature, online system temperature calculation does not work.

64 MHz resolution continuum plus 16 zooms in each IF (the 64 MHz zoom mode)
Online system temperature calculation works as expected for both IFs, in each band except for 3mm. At 3mm, where the paddle is used to calculate the system temperature, online system temperature calculation does not work.

64 MHz bandwidth VLBI tied-array mode
Online system temperature calculation does not work at all in this mode.

1 MHz continuum in IF1, and 64 MHz continuum plus 16 zooms in IF2 (the 1 MHz - 64 MHz hybrid mode)
Online system temperature calculation works as expected, in both IFs and for all bands.