How do I setup my DPO7354C for Phase Noise Plot

I have a DPO7354C with DJE option. I have a 10 MHz source I need to measure phase noise on. 
When I setup my limits of integration for 0 kHz to 100 kHz I only get a portion of this to show up on the plot.
Am I setting up the sampling or scaling wrong?

Hi,

The lowest measurable frequency is the inverse of the acquisition time (which is ten times the time/div). This means that to get measurements for lower frequencies, you should increase the time/div.
To do this you can go into the Horizontal/Acquisition menu and set the Horizontal mode to Manual and then increase the record length (increases processing times) or, if that isn't enough, the sample rate. Make sure not to drop the sample rate to the point that it might cause aliasing of your signal. In your specific case, the sample rate should stay at 25 MS/s and above.

Measurements down to ~10 Hz should be possible, with 25 MS/s sample rate and 250 M record length.

Thanks very much for your help.

Could you clarify what a 250 M record length is? Is that something I setup on DOPJET?

250M record length is about scope acquisition 

As Jeff said, the record length can be configured on the scope horizontal/acquisition menu, not on DPOJET.

For clarification, the record length is the number of points saved to memory per acquisition. That is to say, a 250 M record length implies that 250 million points are saved to memory per acquisition (the duration of the acquisition being 10 times the configured scale or time/div).

Hi Afonso,
A further question about record length.
how can we extend this record length? in my DSA70000, the limit is about 30M that looks for 2 channels at least at same time, can i make it 30M*2 if i just want to measure one channel signal?
or do you have any other suggestion to expand the record length in additional to buy a newer scope:) 
thanks
jeff

Hi Jeff,

From a quick test with my DSA72004, the max record length is 250 million points, no matter the number of channels enabled (this isn't necessarily true for all oscilloscopes). I would assume this is also true for yours with 30 million points.

If 30 million points is not enough for your needs, you can buy an option to enable higher record lengths. The max one is called 20XL (allows up to 250 million points), but there are others for lower record lengths.
 

To order a part call 1-800-833-9200 opt 1.

Or send an email to buy@tektronix.com