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Best 6cm center frequency with CABB

PostPosted: Tue Feb 09, 2010 1:05 pm
by Mark.Wieringa
The current recommended frequency for 6cm observing is 5500MHz. Looking at the autocorrelation noise cal it looks like wild things are happening at the top of the band (from 6380 upwards). Jamie took some data with 5300 MHz as the center frequency to see if things were better at the bottom end.

Here is the standard 5500 MHz setting:
Image

and here is the 5300 MHz setting:
Image

On most antennas the second setting is better, but antenna 4 has a massive spike around 4420 which spoils the picture.

Still, it looks like shifting down 100 MHz, to a center frequency of 5400MHz might be a slightly better option.

Cheers,

Mark

Re: Best 6cm center frequency with CABB

PostPosted: Tue Jun 22, 2010 4:39 pm
by ste616
As part of our attempt to characterise the system temperature at C & X bands, we were able to determine the shape of the noise cal for antennas 3 and 4.

This page fully describes our process, but I've also attached here the noise cal shapes at 6cm.

Image