Help with Rigol DS4014E on 10MHz external ref

[picitup]

I've replied saying I'm unhappy with the response so wait and see what he says.

Cheers

Steve

[picitup]

Well the 10MHz oscillator for £2.98 from fleabay arrived today so i thought I'd give it a go.  As per previous tests, it work well as an external reference as far as the jitter goes which disappeared when it was connected.  So a cheap as chips xtal has less jitter than the DS4000 series internal timebase lol.

I've not heard back from Rigol eu yet, but I'll give it a few more days and then escalate it.

One saving grace though, as discussed earlier, if you start the scope and THEN connect the ext ref, it doesn't lock, you have to cycle the clockout/clockin.  However, if the extref was set to clockin the last time you turned it off, it will lock.  so.... if you have your ext ref always connected and the extref to clockin it does lock during boot up.  Pity there's no indicator on the screen 

I also tried different voltages for the ext clock and it actually works down to 100mV which is nice.  Differing voltages from 100mV to 4V don't help the locking/jitter situation though.

Cheers

Steve

[TurboTom]

There's a new firmware for the DS4000 series available from Rigol's chinese download site: http://www.rigol.com/Support/SoftDownload/3
It is version 02.02.01.01 (02.03 SP1), released on August, 15 2017. Strange enough it apparently didn't show up un any english-language server. I tested it but unfortunately, regarding the problem discussed here in this thread, it wouldn't make any difference. Most notable change is that the vertical position controls are now dynamically accelerated which in my opinion is quite comfortable. Let's hope Rigol continues to support the firmware, also taking care of the clock jitter problem.

Cheers,
Thomas

[picitup]

Hi Thomas

Thanks for the link and info.  I've downloaded the firmware and will install it later on today.  I wonder what the "Storage Problems" were that have been fixed?

Well it's been 6 days now since I complained I wasn't happy with the answer from Rigol EU so I've knocked up an email for Rigol NA as follows:

Dear Sir/Madam

I wonder if you could help me escalate an issue with my DS4014E oscilloscope.  I have been dealing with tech support at Rigol Europe but have been unable to make any progress.

There are a number of issues I am trying to address and here's a summary below:

1) Poor documentation for the external ref input
2) Difficulty making the scope phase lock to the timebase
3) Difficulty proving a the phase is currently locked
4) High jitter when using long timebase delays

I have been very pleased with the scope so far, in terms of price, features and value for money, but am surprised at the lack of support for the 10MHz ref input.  I'll run through the list above in order:

1) Documentation
===============
If you look at the product manual here:

https://www.rigol.eu/products/digital-oscilloscopes/4000/

The page deals with the reference clock.  There are no electrical specs for the interface such as allowable voltage range, input impedance, frequency range, sine/square and so on.  These specs would be very helpful.

2) Achieving phase lock
====================
If you switch the scope on, switch the RefClock to ClockInput and then connect the external 10MHz reference, the scope does not lock.  You have to change RefClock to ClockOutput then ClockInput and it then locks.  If you then remove the 10MHz and plug it in again, phase lock is lost.  You have to once again toggle ClockOutput/Clockinput and it locks again.

I've tried the above with a range of voltages from 1-3.9vpp and with sine and square waves and the result is always the same.

What I expected was to plug the external 10MHz reference in and the scope would phase lock without me toggling the RefClock.  I don't feel very comfortable connecting two outputs together as I worry about damaging the equipment.

3) Demonstrating Lock is Achieved
=============================
There is no indicator on screen I can see to show that phase lock has been achieved.  This would be very helpful, especially given the difficulties above.  Just an icon or filled in circle or square would be great on the LCD.

4) Excessive Jitter
===============
When using long timebase delays of, say 100mS, the jitter becomes excessive.  I've attached a couple of screenshots for you to look at.  The one with high jitter is the internal timebase measuring a 10MHz gpsdo signal on CH1.  The one with no jitter is using the gpsdo as the external 10Mhz reference.

As a sanity test, I purchase a tin can 10Mhz crystal oscillator from eBay for under £3.00 and used this as the external reference in the same test.  There was no discernable jitter so it seems a cheap oscillator has much less jitter than the DS4000 internal timebase.

I'm sorry this email is so long, but I wanted to include as much detail as possible.  Hopefully all of the above issues could be dealt with in a firmware upgrade.

Kind Regards

Steve

Let's see what they have to say.

[picitup]

Well 20 minutes after emailing Rigol NA I got a message from Rigol EU.  Coincidence? lol.

He's passed it on to Rigol China but it's the new year now till the 25th so there will be a delay in the reply.

I'll keep everyone posted.

Cheers

Steve

[picitup]

Well it's been a week since the end of the Chinese new year without a reply so I've given Rigol EU a nudge.

I'll post up any response.

Cheers

Steve

[picitup]

Well still no reply from Rigol EU and it's been another couple of weeks, so I've nudged again.

Cheers

Steve

[Gandalf_Sr]

I just read through the entire thread.  The Rigol test seems to say that you should input a 3Vpp square wave into the Ext 10 MHz in but you said that your 10 MHz signal was only 1 Vpp - are you sure this isn't the issue?

I've been thinking about making a distribution Amp for my workshop so I can use my GPSDO, the design I'm favoring has both sine and square wave outputs so clearly the 10 MHz in is not a standard thing, I've read that some people using 10 MHz square waves have problems with their equipment being confused by harmonics.

[Performa01]

I just read through the entire thread.  ...

Are you sure?

The documentation for this feature is very poor and after a number of emails to Rigol I managed to extract from them that the external clock is 10MHz, 1-4vpp square or sine wave and is a high impedance input.

I tested the external sync on my DS4054.

* Connected 9.999MHz sine at 3.3Vpp to CH1.

I tried a few different voltage measurements from 1 - 3.9 vpp and square an sine wave, but all worked in the same weird fashion.

I also tried different voltages for the ext clock and it actually works down to 100mV which is nice.  Differing voltages from 100mV to 4V don't help the locking/jitter situation though.

... plus some more quoted mentions

[Gandalf_Sr]

The Rigol 10MHz Test pdf Document that picitup linked to is where I got that from - see picture.

[picitup]

Hi

Just to clarify I did try a range of voltages from 1-3.9vpp but it didn't change anything.  There are also the issues of jitter and having to cycle the extref in/out.

I'm in Spain now lol so might be slow to reply.

Cheers

Steve