256 QAM source won't lock

[cbohanno]

I am trying to use the Modulation toolkit to make some measurements on a M-256 QAM digital video RF signal. I am unable to get it to lock and I am (unfortunately) very new to Labview as well.

I can see the signal clearly in the power spectrum, so I know that it's there, but I'm not sure if the problem is the signal itself or my code. I'd appreciate if someone could tell me if there's any obvious mistakes.

Thanks!

[Sastry]

Try increasing the number of symbols and/or the filter length as well. I am assuming you have 5660 ? With 5660, I would doubt if you would get lock at rates as high as 5M.  But please try the above and see if it helps.  Furthermore, try locking the reference clocks between your signal generator and analyzer as well.