Measured Interference Plots at the AT Compact Array

The recommended frequencies for the four main observing bands are shown on the white-board in the control room of the ATCA, including the fluz of 1934-638 at each band. Currently these frequencies are 1384/1344, 2368, 4800 and 8640MHz for 20, 13, 6 and 3cm.

Particular points to note for interference, you should take care to avoid multiples of 128MHz. Also narrow band (a few MHz) interference from mobile phones can be found in harmonics of 824-849MHz.


Figures: Worst interference at 20, 13, 6 and 3cm at the Compact Array on 5 April 1995. The baseline length was 153m, the frequency resolution 62.5kHz, and the fringe rotators were switched off. The data plotted are a 1 min scalar average. Arrows indicate 128MHz sampler clock harmonics. Observations by D.J. McKay.