Signal envelope changing...?

[snuzzbff]

I'm trying to generate two sinuosoids (one right after the other) that are offset from a carrier.  I know they are being generated and can be picked up and displayed by the RFSA.  Everything up to that point appears fine.  However the envelope of the signal is not constant even when I go above and below the carrier the same amount for the same power level, etc.  So my question is if there's any way to fix this issue?  Any insight is appreciated. 

Thanks.

- Eric

[Travis G.]

Hello Eric,

The first thing I would check is to make sure that you are using the latest version of the NI-RFSA driver (NI-RFSA 2.0.1).  There have been a few fixes implemented in this driver that impact how the attenuaters in the PXI-566x work.  Which brings up the question, what exact hardware are you using?

It would be helpful if you could attach a screenshot of the behavior you are seeing, along with the specific settings used to configure the device.  Is there a specific NI-RFSA shipping example that you are running to demonstrate this behavior?  Let us know some more information about the behavior you are seeing and we can probably provide some suggestions.

Travis G.
Applications Engineering
National Instruments
www.ni.com/support