Author Topic: MSOX-2000 Owners - Does your scope have this problem #1? (Read 9899 times)

jstarr · « **on:** May 14, 2013, 12:05:06 pm »

I was looking at Dave's video on the Rigol DS2000 to show the effect of persistence and intensity of signal on the screen and tried to reproduce it on my MSOX2024. Either with the WavGen option or an independent external source Set up for a 1 Mhz Sine wave with AM modulation of 100 hz and 100% modulation. Set scope for either 5ms or 2 ms - can you find a stable trigger lock? My MSOX2024 cannot and has quite a bit of jitter in RUN. You can try this also with 1Mhz sine and 1khz AM modulation and a horizontal of 500us or 200us and same thing - jitter and not a stable screen picture in RUN. IS this inherent problem or just my scope?

j

Nermash · « **Reply #1 on:** May 14, 2013, 12:41:46 pm »

Think a little about triggering... Don't blame the scope first

jstarr · « **Reply #2 on:** May 14, 2013, 12:55:52 pm »

I reproduced what Dave showed in his Rigol DS2000 video, I did not see any instability in the his vidoe on the DS2000 display. Identical conditions in MSOX2024 cannot get stable signal. Perhaps you can explain why the different behaviour between the two scopes? I can understand that at 0% modulation you may lose the trigger but then there should be a missed trigger event not a shift in the underlying heterodyne frequency. Is it a "feature" or a "problem"

j

EV · « **Reply #3 on:** May 14, 2013, 01:14:41 pm »

You must set trigger level and holdoff to a suitable value.

Hydrawerk · « **Reply #4 on:** May 14, 2013, 02:03:22 pm »

In complex signals, never rely on the Autoset button.

ben_r_ · « **Reply #5 on:** May 14, 2013, 03:23:31 pm »

Quote from: Hydrawerk on May 14, 2013, 02:03:22 pm

In complex signals, never rely on the Autoset button.

Taking that a step further I never rely on the Autoset button AT ALL!

jstarr · « **Reply #6 on:** May 14, 2013, 04:45:15 pm »

I did NOTuse Auto but tried a variety of trigger settings, levels, holdoff/delays and no setting could provide a stable triggered signal under the conditions tested (same as Dave's in his DS2000video). I am not trying to bad-mouth the MSOX-2024 - I own it! I just want to find out if this is an intrinsic problem in the model or a problem only with my scope.

Can anyone who owns a MSOX2000 try this PLEASE and provide feedback here?

tia
john

PA4TIM · « **Reply #7 on:** May 14, 2013, 05:02:04 pm »

I have not seen that video so I probably am thinking the wrong way but just to be sure
- you have no troubles triggering in normal use ? ( could it be something in the menu settings ? Just a wild guess. Something that is not a menu choise on the Rigol but is on the Agilent, so Dave does not show that setting ? like a friend with the same scope as me did not manage to get the same picture as me because a menu setting I had switched on and he had never used)
- not to offend you but you are only human too ( I hope ;-) ) the trigger source is on the right channel ?

Do you have a link to that video ? The Agilent is an other scope as the Rigol and I have a good DSO from Hameg ( 350 MHz) . If you have a link I will try the same thing on my Hameg and see if it does the same thing as Agilent or as the Rigol.

EV · « **Reply #8 on:** May 14, 2013, 05:09:05 pm »

Here is 1 MHz sine modulated with 1 kHz. Holdoff is 800 us. Look at the picture.

AndyC_772 · « **Reply #9 on:** May 14, 2013, 05:20:44 pm »

Here's the signal you describe, with a perfectly stable trigger on my 3054A.

The trick is to set the holdoff correctly. You want the scope to trigger when the waveform first crosses the trigger threshold, but then to not re-arm the trigger circuit again until after that particular AM cycle has decayed away. In this example, the amplitude of the AM signal exceeds the trigger level for a period of about 4ms per cycle, so by setting the holdoff to 5ms I ensure that when the scope has triggered once, it won't trigger again until the next cycle reaches the necessary amplitude.

jstarr · « **Reply #10 on:** May 15, 2013, 02:18:06 am »

Thanks EV and AndyC_772.

This confirms my MSOX2024a needs servicing. I cannot get the display to stop the jittering even when setting my scope with holdoff as you describe... Holdoff seems to have no effect at any setting. I have one other problem in the Wavgen I want to post in a new topic to see if that needs repair as well.

j

ben_r_ · « **Reply #11 on:** May 15, 2013, 05:27:59 am »

Just setup the same wave on my MSOX2024A: 1Mhz Sine, 1Vp-p, AM Modulation, 100Hz Freq, 100% Depth outputted from an Agilent 33220A.

Signal sits perfectly still once the trigger level was set at around 500mV for this example or about half way to the peak.

EEVblog · « **Reply #12 on:** May 15, 2013, 05:43:04 am »

Quote from: jstarr on May 15, 2013, 02:18:06 am

This confirms my MSOX2024a needs servicing. I cannot get the display to stop the jittering even when setting my scope with holdoff as you describe... Holdoff seems to have no effect at any setting. I have one other problem in the Wavgen I want to post in a new topic to see if that needs repair as well.

I find it hard to believe your scope is faulty in this respect. It is just very very unlikely.
Are you absolutely sure you don't have anything else screwing up the triggering?
Yes, like the others, it goes stable with about 500ns of holdoff and say level at 3/4 peak.

ben_r_ · « **Reply #13 on:** May 15, 2013, 05:49:42 am »

Yes, like so:

EV · « **Reply #14 on:** May 15, 2013, 07:50:22 am »

Quote from: jstarr on May 15, 2013, 02:18:06 am

I cannot get the display to stop the jittering even when setting my scope with holdoff as you describe... Holdoff seems to have no effect at any setting.

Have you set the tigger level also as in my picture?

jahonen · « **Reply #15 on:** May 15, 2013, 08:17:24 am »

Perhaps you have trigger HF reject and/or noise reject turned on?

Regards,
Janne

Sander · « **Reply #16 on:** May 15, 2013, 04:34:22 pm »

ben_r_ have you got the memup-option? I can't get it to use 10.0MSa/s, might be because I haven't got that option (yet...).

Looks like this on my unit:

ben_r_ · « **Reply #17 on:** May 15, 2013, 05:14:29 pm »

Quote from: Sander on May 15, 2013, 04:34:22 pm

ben_r_ have you got the memup-option? I can't get it to use 10.0MSa/s, might be because I haven't got that option (yet...).

Yes, I do have it.

EV · « **Reply #18 on:** May 15, 2013, 05:54:00 pm »

Quote from: jstarr on May 15, 2013, 02:18:06 am

Holdoff seems to have no effect at any setting.

Press the Single key. What do you get then? Attach a picture for us.

jstarr · « **Reply #19 on:** May 15, 2013, 06:15:49 pm »

EV, Ben_r_

I am almost certain but will check again when I get home. BTW, what software/link are you using to get the nice colored screen shots? I have IntuiLink and it seems only to provide B&W. I guess I need the VGA/Lan adapter?

thanks
j

ben_r_ · « **Reply #20 on:** May 15, 2013, 06:21:35 pm »

Quote from: jstarr on May 15, 2013, 06:15:49 pm

EV, Ben_r_

I am almost certain but will check again when I get home. BTW, what software/link are you using to get the nice colored screen shots? I have IntuiLink and it seems only to provide B&W. I guess I need the VGA/Lan adapter?

thanks
j

I am using the Agilent VGA/LAN card. Gives you tablet control, VGA out, screen capture, browser control, and setup options. Pretty cool actually if you can get it for a good price.

EV · « **Reply #21 on:** May 15, 2013, 08:06:40 pm »

Quote from: jstarr on May 15, 2013, 06:15:49 pm

BTW, what software/link are you using to get the nice colored screen shots?

I don't have this scope, but it should be possile to save screen image with Save key. Look at your users manual.

Hydrawerk · « **Reply #22 on:** May 15, 2013, 08:19:20 pm »

You can save the png printscreen to your USB flash disc by pressing Save/Recall or you can use the Quick Action button. (After you configure it!)

ben_r_ · « **Reply #23 on:** May 15, 2013, 08:26:22 pm »

Yea thats whats nice about having the VGA/LAN card in the Agilent scopes. All I have to do to get a screen shot is go to my computer, click the saved link to my scopes IP address and click the Get Image button on the first page and I have a screen shot ready to save. Super fast and convenient. If you need/want the feature its very nice to have.

EV · « **Reply #24 on:** May 16, 2013, 09:54:46 am »

If you can not get the trigger work from CH1, you can at least do like I have done in the attached picture. There is 1 MHz sine wave modulated with 1 kHz sine wave in CH1. Scope is triggered from CH2 where is 1 kHz sine wave. Trigger position and holdoff value are not critical.


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Author Topic: MSOX-2000 Owners - Does your scope have this problem #1? (Read 9899 times)

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