John, It's interesting that there is almost no evidence of the 500 MHz ADC clock, except perhaps the 2000 MHz tone. I guess that means the ADC clock transmission lines are well terminated and not radiating. Most of the lines look like they are related to the PPC (multiples of 33 MHz) and the 100 MHz system clock. Glenn
On Tue, Sep 6, 2011 at 1:14 PM, John Ford <jf...@nrao.edu> wrote: > Hi all. > > We tested a ROACH and and 2 ADC boards (3 GS/s boards) in our anechoic > chamber to get a feel for the emissions to expect from the new > spectrometer being designed. The ADC clock was running at 500 MHz. > > The results of the test are attached. In summary, to use these at our > site, we will have to have a supplementary shielded enclosure in addition > to our shielded equipment room. > > Thanks to Carla Beaudet at NRAO for the testing. > > (If anyone has anything they'd like us to test in the chamber, let me > know.) > > John
