AnsweredAssumed Answered

unwanted signals around the desired signals on M8190A

Question asked by ray on Aug 29, 2012
Latest reply on Sep 1, 2012 by tdippon
Hi, Agilent guru on M8190A,
I just got 2 of M8910As (product version 2) to replace original version 1 unit. I was trying to generate multiple tone signals from M8190As. But I always got unwanted multiple products of signals around my desired signals with freq. offset 20.8KHz (for 312,000 sample length), or 2.08KHz for 3,120,000 sample length.  Even if I loaded all "1" to channel 1 and "0" to channel 2, I still got the same problem. Sometimes it didn't show up and the signals were very clean. But most of time it happened, on both of my units. 

I didn't get this problem with my version 1 unit. 

I have thought of and checked ref signal, sampling signals from internal (which always has +/1 270Hz signals around from "Sample Clock out" port) and rebooted PC and M8190A (and driver) many times, but couldn't find even a workaround!!  Very frustrated!!  

FYI, I am using C# to generate the DAC values and load to the unit with IVI driver.  But like I said, even loading "1" and "0" will cause the same problem. I am almost coming to the conclusion that the hardware has the problem.

Your timely help is truly appreciated!!!