Facilities > GBT > Observer Alerts > VEGAS Analog IF module Improvements

VEGAS Analog IF module Improvements

by Toney Minter last modified Sep 09, 2015

VEGAS Spectrometer:  New Analog IF Modules – 2015/09/09

In a previous Observer Alert (VEGAS Spectrometer Bank to Bank Variations Resolved) we reported that VEGAS bank-to-bank variations in system temperature and line intensity had been traced to excess crosstalk (signal leakage) between the two polarizations (X and Y, or L and R) processed by the same VEGAS Analog IF Module. As the long-term solution, we have redesigned these modules, and packaged each polarization for each Bank separately. The first such pair of modules have been tested, and demonstrated to resolve the problem, as expected.

The first module was inserted into VEGAS Bank A on 9th September 2015. Observers should see no change in behavior compared to the current (interim fix) configuration. As we remove old modules from service, the microwave components will be repackaged into the new design, and additional new modules released. This work will continue over the next few weeks.