Recent Posts

1

Projects, Designs, and Technical Stuff / Re: No interrupt from AS6501...

« Last post by Denge on Today at 03:21:53 pm »

Hello,

Thanks for the reply!
For CF2 the datasheet says that bits 6&7 are useful or SPI.

I copied your setup but without any succes for the interrupt pulse: the interrupt simply doesn't go low and I have still no idea why this is not happening!
The sequence I us is:
- write the config registers
- verify the setup
- initialise and start the measurement
- readout of measurement data

However, I never reach the read out as my program stalls on waiting for the interrupt.

The stopA and stopB pulses are generated with an AFG, so well defined.
Any idea why this interrupt is not going low?

Groeten.

2

Repair / Re: Rigol DP712 Output Shorted; Fuse? / I Screwed Up

« Last post by macboy on Today at 03:20:00 pm »

Nearly all lab supplies will have a reverse-biased rectifier diode across the output terminals. In some "normal" usage cases, this will prevent a reverse voltage from appearing across the terminals, which could damage various components (output transistors, output capacitors, etc.). Such a case is when using two supplies in series (to get higher output voltage), and one goes into current limiting mode, while the other continues to try to push more current.

Anyway, this diode is easily damaged by doing things like connecting a powerful battery or another power supply in reverse, or sometimes even just by using the supply/supplies in "normal" series operation. I've seen 1 A reverse diodes on a 3 A supply! You can imagine what would happen in the above scenario if the second supply is pushing 3 A through a 1 A diode.

Rectifier diodes usually fail short circuit. Of course, not a perfect short, but with some resistance (it is a semiconductor after all). Based on the symptoms you see, I would strongly suggest looking for this diode and testing it. You can check if the diode is the problem simply by removing it (or lifting one leg), then testing the supply.

You could also test it with a multimeter in diode test mode. Turn off and unplug the supply. Short the terminals (to discharge the output capacitor, just in case) then remove the short. With a multimeter in diode mode, connect test leads to the + and - outputs of the supply. Test in both directions. If the diode is good, the meter will show approx 0.6 V forward voltage (a good diode) in one direction, and open/over limit in the other direction (it may start low and slowly climb up, as the output capacitor of the supply is charged by the multimeter test current). If the diode is bad, you will measure 0.6 V or lower in both directions.

3

Dodgy Technology / Re: KCD-11 rocker switch from aliexpress is junk

« Last post by Stray Electron on Today at 03:19:47 pm »

Mechnical contacts can be tricky with small signals. A good low ohm contact may need a certain minimum current to flow.
The switch could well be OK for other uses (e.g. to switch a light or possibly even mains).

  X2.  The OP should look up the term "sealing current" or "wetting current".   I found out about this early in my career when I tried to use a normal AC switch in a low current digital circuit.  A digital rated switch was about 3x the price but it worked and a standard switch simply wouldn't, even when brand new.

   Also on those Chinese made switches it very likely that the contacts were made of steel and had a very thin layer of tin on them and that the plating wore through very quickly. I've found that to be VERY common in cheaply made wire, bulbs, sockets, switches, etc. 

4

Beginners / Re: Bulk input caps and impedance

« Last post by paulca on Today at 03:14:55 pm »

I hooked a 220uF (cheap) cap to a 14.5V PSU.

Put the scope on it.  Connected the power with no resistor.  15us.  63kHz.  With only 1/4 of that accounting for the majority of the rise.

(The PSU does have a 5Amp limit, but it did not click with such a small cap.)

With a 47Ohm resistor it takes 82 miliseconds.

The linear (almost) portion of the initial rise, I can get a V/s for that.  I should be able to calculate the current to produce that gradient?  I should also be able to then compute the ESR of the full circuit?  With or without resistor?

Now I want to try what an inductor does.

5

Test Equipment / Re: New Zoyi multimeter+oscilloscopes - ZT-70xS, up to 50MHz/250MSps (nov 2022)

« Last post by ksxx on Today at 03:09:34 pm »

I did some tests with the Zoyi and some other meters I have access to. The AD780 was trimmed to give a 2.5000V output on the (old) HP desktop meter. The film capacitors were measured with an Agilent 4294A impedance analyser at 10KHz. The table shows that my 703S gives the results closest to the ones by the more advanced equipment. Yet most of the meters tested do well enough for most situations. Even the 10$ T7 component tester gives great results!

6

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by wasedadoc on Today at 03:09:31 pm »

by theory, Sinc should be able to reconstruct grey wave (original wave) from blue dots (sampled points)

Riddle me this:

Signal theory also says there's only one curve that fits a set of sampled points in a bandwidth limited signal.

The "AM" signal fits perfectly so how can we say it's possible to reconstruct the original sine wave? It contradicts theory.

The theory applies if the reconstruction filter is a perfect low pass filter with regard to the highest frequency component that was present in the original continuous version.  (And that the sampling rate was at least twice that of the highest frequency component in the original.)  A perfect low pass has a sinc impulse response and that has infinitely long pre and post tails.  No practical implementation can achieve that.  The '/x' part of sin(x)/x diminishes only slowly as x increases.  Truncating or windowing the sinc introduces discrepancies which become more significant as one approaches half sample rate.

The undulations

7

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by awakephd on Today at 03:05:51 pm »

Friends, again I thank you for filling in some of the gaps in my ignorance. I probably will not attempt to keep up in this thread, as the discussion has left me behind - I sorta kinda understand some of what is being discussed, but it is way beyond my current needs and abilities. This is not a complaint - it is the nature of open discussions to go where they will. I just don't want anyone to ask a question to the OP (me), get no response, and think I have taken my marble (only one, and it is cracked!) and gone home. I may start a new thread when I am about to pull the trigger on a purchase - only about a month away, now - can't wait!

8

Test Equipment / Re: Hacking the Rigol MSO5000 series oscilloscopes

« Last post by BTO on Today at 03:04:59 pm »

Regarding Restore Defaults in the Pre Boot Menu, I believe this is a pretty important step when downgrading firmware as the stored settings are not necessarily backwards compatible and could cause weird behaviour.

- After my testing, i disagree (i was off that opinion 2 days ago as well, I'm off a new opinion now)
[snip]
I wouldn't worry about it,  I did this several times

Hi mate,
sorry i was in a rush before and when i replied i thought it was a P.M.  so let me address those points again for the entire forum to see.

Sure.  You may not see any problems between those two recent firmware releases you tested with, but that is quite a limited test especially if you aren't using the scope feature between versions in such a way that defaults get changed.

- In a way it's limited, because it's limited to only my scope, but if our concern is between "Only 2 versions".. No i have done more than that.
I have gone from 1.3.3.0 - 1.3.2.2   then i have gone down to 1.3.0.3  and i think the other one was 1.1.4.4 (Just to push my luck)
After using Dr Mefisto's method i was able to downgrade to basically any version and still retain my unlock options with NO PROBLEM WITH THE SCOPE.

then i repeated this multiple times, 15 times or more all in all.  I really wanted to test it specifically so that it was not a one-off test. i really tried
to get the scope to fail at certain point.. It never did.
Now, Most users will not even attempt what i have done, Most are just going to go from their current version which is either going to be
1.3.2.2  or 1.3.3.0

There have definitely been issues in the past when going between various releases without defaulting the settings

- I have literally read and re read through the ENTIRETY of Unlocking DS1052E , Unlocking DS2000A and Unlocking MSO5000 .
i did this just to catch up again and when it read through you start to see (with hindsight) what the problems were, so my response to this point is..

- There have been issues, Definitely
- But those issues were made without hindsight and jumping in the deep end and a lot of assumptions took place, then people jumped to conclusions
based on false logic that we should DEFINITELY do the Restore Default thing... or else !!

No that's not the case.
I also read that a few users said that Restore Defaults gets rid of the installed Options.. THAT'S NOT CORRECT.
Restore defaults just takes your scope to default settings (if you have custom settings applied or a .stp setup file applied) that's all it does.
i have tested and proven that it does not uninstall your options , nor does it downgrade your scope to the factory state that you bought it in (after an uprade).

BUT. I AM AN ADVOCATE OF DOING THIS STEP JUST FOR GOOD MEASURE.... i mean.. Why not . it doesn't take long to do so i agree it is a good idea.
but i would stress. it's not a necessity and don't see it as such.

So a user who has an unit that they've been actively using with older firmware is more likely to have a problem.

Ummm,  No, i would say not, Because i downgraded to 1.1.4.4 and had no issues and i don't know anyone who has gone that low.
When i bought my scope it was on 1.3.0.3 , i think at this stage no one is on a lower version, Everyone is one 1.3.3.0  or 1.3.2.2  or 1.3.0.3
i haven't seen any lower.
But i am so confident that this method works that , If a member of the forum has a lower version, i am happy to test their version on my scope
before they upgrade it.
Seriously mate, i have tested the shit out of this, from version to version , up and down and sideways and switching between patched and licensed
and basically combining any option that popped into my head.  Never had a problem.

Not a big deal, it just wasted some of my time when I encountered it and had to got back to that menu.  And in my case I was upgrading not downgrading - I believe from 0A.01.03.00.01 to 00.01.03.03.00.

- Sure and when i started trying this out i also encountered a lot of errors, but as we said before
A Lot of users seem to lack technical experience and programming experince
I had the benefit of having coding experience and I.T. and Electronics for decades. Granted i had to dust off my Python Cobwebs in my brain
from my Uni years but.. it came back to me.
and since i hadn't installed Python for a very very very long time i also had hitches with the modules, but i worked it out pretty quickly.

I can absolutely see how a newbie user would get stuck here.
i can also see how that rumour of the black screen hanging came about,  it doesn't actually hang, you just need to be patient.
worse case scenario, Just restart your scope, it'll be fine
Another thing that accidentally happened, .... while using Powershell (Because i tried it on Powershell and Windows C.L.I.) i accidentally clicked
on the screen while the chip was being flashed.  AND THE PROGRESS BAR STOPPED !!!
i felt like Lefty on Donnie Brasco when he got "sent for " for a second.   then i realized   P.E.B.K.A.C. .
You just need to right click on the screen to take it out of Pause.  the install didn't fail, you just need to know not to click on the screen while
it's progressing

I think a lot of these issues arise from misunderstanding or lack of knowledge

Similarly, it is pretty important to run the self cal after an upgrade (and warm up).  The scope will work without it, but may not meet specifications.  I haven't watched all your videos, but I expect you cover that.

- Yes i've definitely covered that and i agree, it is essential after the upgrade to do a few things

1. DO A SELF CAL
2. DO A SELF CHECK (go through all 3 tests)
3. then DO THOSE 2 BACKUPS AGAIN

I would deem these POST Steps to be mandatory

I thought I saw it was available for the MSO7000

so for everyone's benefit
THIS IS REGARDING JITTER AND EYE ANALYSIS on the MSO5000
Which was seen in the scope with the patched version, And.. For me
- Jitter did work
- Eye Analysis worked for a bit and then it stopped and i couldn't get it to work again

Let me also explain for the benefit of the newbies....
JITTER is a "Software Option Package" they call it a "Bundle" so.. when Rigol unlocks software options they unlock it on a Bundle to Bundle basis.
they don't unlock it on a feature per feature basis, Meaning, if you want Eye Analysis, you MUST take Jitter as well.

so, that being said
Yes i also thought it was on the MSO7000,  Apparently not. Apparently (According to the manuals) it doesn't kick in until MSO8000.
which now leaves me wondering, since you can do Eye Analysis and Jitter on the scope anyway, what is the point of having that option anyhow ?
I"m still looking into that

However if we could figure out a hack to have that option in the MSO500 that would be cool, but as i understand the hardware doesn't support it.
However that doesn't really make sense to me since it's all just a software calculation isn't it ?

i have also seen you tube videos on Eye Analysis, but not many, and of those that i've seen they are using either Tek Scopes (It apparently comes standard) or they are using Rigol MSO8000, there is one guy using an MSO5000 HOWEVER HE IS NOT USING EYE ANALYSIS MODE, But instead
he is just using the scope to show how to troubleshoot with COLOR GRADE while doing Eye Analysis and Jitter.


IN CONCLUSION :
I am EXTREMELY CONFIDENT that Dr Mefisto's full licensing method via the python script works very well.
HAT OFF TO DR MEFISTO

i think we currently have the following issues that are stopping people from proceeding with the upgrade

- FEAR (in general)
- FEAR OF CHANGE

- Perhaps there is a feeling of... "Ohh well it's patched and working so why bother"
The answer is.. Because you'll have to do it eventually.   I can assure you all of you (as i am currently speaking to a senior engineer at rigol)
there will be another upgrade, it will primarily be resolving all the stupid grammatical and spelling errors so that we have a manual that is actually readable and makes sense especially to beginners and they are going to address memory optimization issues , hopefully the scope starts faster
as well as getting rid of 1ks/div Timebase in an effort to make COLOR GRADE more responsive at the lower time frames)  so.. there is another one coming i can assure you.
so if you don't do Dr Mefisto's method now, You'll be doing it later, that's for certain

- Then there are lingering rumours of this and that crashing.  I have found most of these are misunderstandings

- There is "it just seems so hard to do " thing....  No worries, I'm happy to walk anyone throught it, and .. it really isn't that hard to be honest.

- there is the "will it brick my scope" thing.
Well... NO IT WON'T
You just need to ensure a few things and be very careful
1. Ensure it doesn't lose power, so .. maybe like.. you can't kick the power board accidentally or something
2. Dont' do it during a lightning storm or if your area recently had power outages
3. Ensure that under no circumstances does your ethernet cable get disconnected during the flash process
4. Ensure that your router isn't a shit router and that it doesn't lose power during the process

and it's not the entire process we are worried about , it's only for that .. maybe 2mins of Flashing (Where Power and network is critical)
or
When you're doing a firmware upgrade or downgrade (here, Only power is critical, Network doesn't matter)
that aside.. You are not going to brick your scope.

- then there's the "but what if there's something in the script that stuffs up my scope"  thing
well..........THERE ISN'T , I've checked it out

- Then there's the (i have heard rumours)  and maybe Dr Mefisto can she some light.
the rumour is since we all have MSO5000  (5074) for the most part. the script is written for 5074
but,, if you have MSO5014 (as i heard)  it doesn't work on it

- Well, i can't see that making sense as the MSO 5014 is the same scope just with 70MHz - 100MHz Unlocked

SO IF THAT WAS THE CASE,  You could just use the script and since that's a software options, Just uninstall the option.
After that treat is as normal

I can't see how it's relevant, because
- The script checks for installed Bundles
- It then checks for available bundles
- it then installs ALL AVAILABLE BUNDLES FOR THAT SCOPE

I have also heard that there is a solution for the MSO5014 issue and that is to change a line of code.............. OK, WE'LL CHANGE IT,
it's not a big deal


so i think we are at the point where people just need to stop being scared , as i said I'M HAPPY TO TEST THIS AND SHOW RESULTS

so if you guys have any fear (i am that confident in Dr Mefisto's method)  Tell me your fear and i'll test it on my scope and let's put the fears to rest
and get everyone upgraded

I'm still in the process of making that video to upgrade via Dr Mefisto's method,   it will contain a lot of things you guys are talking about and i'll hopefullly put all that to rest.

speak soon
sorry for the long post

9

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by gf on Today at 03:04:38 pm »

Riddle me this:
Signal theory also says there's only one curve that fits a set of sampled points in a bandwidth limited signal.
The "AM" signal fits perfectly so how can we say it's possible to reconstruct the original sine wave? It contradicts theory.

Perfect reconstruction requires an ideal brickwall interpolation filter (-> infinte length).

With a realizable interpolation filter, the reconstructible bandwidth becomes lower.
For example samle_rate / 2.5. The actual denominator depends on the frequency response of the filter, see my previous message.
The point where the filter starts rolling off is basically the the reconstructability limit.

10

Buy/Sell/Wanted / Selling Signal Hound SA124B

« Last post by gsmaudis on Today at 02:56:22 pm »

I'm selling my Signal Hound SA124B 100kHz to12.4 GHz spectrum analyzer.
In full working order, it was bought directly from the manufacturer.
I'm asking $980 including shipping within the wordwide.
Included are the SA124B and USB cables.
Software is available off Signal Hound's website: https://signalhound.com/spike/