Rigol DSO question

[bitrex]

Is there a way to set up a Rigol scope, DS1102E in this case, to check
for longer term frequency stability of some signal?

It seems to display frequency of signals sometimes when it can figure it
out, and you can pull up a FFT, but the averaging period is pretty short

 

[George Herold]

On Wednesday, August 7, 2019 at 11:52:46 AM UTC-4, bitrex wrote:

Is there a way to set up a Rigol scope, DS1102E in this case, to check
for longer term frequency stability of some signal?

It seems to display frequency of signals sometimes when it can figure it
out, and you can pull up a FFT, but the averaging period is pretty short

What frequency and how much change might you want to see?
You can trigger on the signal, set the scope for a long time delay,
and then watch it, or put the the 'scope into infinite persistence and see
if the waveform moves.

George H.

 

[bitrex]

On 8/7/19 12:22 PM, George Herold wrote:

On Wednesday, August 7, 2019 at 11:52:46 AM UTC-4, bitrex wrote:
Is there a way to set up a Rigol scope, DS1102E in this case, to check
for longer term frequency stability of some signal?

It seems to display frequency of signals sometimes when it can figure it
out, and you can pull up a FFT, but the averaging period is pretty short

What frequency and how much change might you want to see?
You can trigger on the signal, set the scope for a long time delay,
and then watch it, or put the the 'scope into infinite persistence and see
if the waveform moves.

George H.

Thanks, Display > Persist = Infinite is perfect

 

[Dave Platt]

In article <etC2F.535360$xm4.330232@fx45.iad>,
bitrex <user@example.net> wrote:

Is there a way to set up a Rigol scope, DS1102E in this case, to check
for longer term frequency stability of some signal?

It seems to display frequency of signals sometimes when it can figure it
out, and you can pull up a FFT, but the averaging period is pretty short

If you have a good, stable frequency reference operating at the signal
frequency, you can set up the Rigol in dual-trace mode (triggering on
either one of the signals) and have it measure the time between the
zero crossings of the two signals. Plot this and you can determine
the phase shift per sweep, and figure out the frequency difference.

This only works (meaningfully) if your reference and test frequencies
are very close together. I used this approach to compare two 10 MHz
signals... one from a GPS-disciplined oscillator I was working on, and
the other from a surplus rubidium reference.