Please select To the mobile version | Continue to access the desktop computer version

Electronic Engineer Discuss

12Next
Return to list New
View: 3319|Reply: 10

Hantek 6254BD USB scope probe pp-250 not 250MHz capable

[Copy link]

1

Threads

5

Posts

5

Credits

新手上路

Rank: 1

Credits
5
Post time 2017-6-15 09:31:31 | Show all posts |Read mode
Dear madam, sir,
Recently I purchased a 6254BD 250MHz USB oscilloscope, I must say I’m impressed with the build quality of the unit, but there are a few problems however.
Most important, the supplied PP-250 probes are not capable of reaching the 250MHz bandwidth, after some testing they appear to be about 120MHz capable ( I will include some screenshots in which I compare a 150MHz probe to the PP-250 probe at 20MHz and 125MHz sinewave. The yellow trace is the PP-250 and the blue trace is the Rigol probe). The probes were compensated on the 1KHz square wave and set to 10x. I also contacted the seller about this, because without proper probes the oscilloscope cannot be used to its full potential.
   

Other, less important, things are:
  • There seems to be a significant amount of jitter on the trigger, especially visible on low time basis.
  • When I try to store a screenshot with the Hantek software it doesn’t show the full screen (I use a 4K display)
              

There some other things that don’t seem to work well but I leave it at these, because I think they are the most important. If you are interested, I have also some feature requests which would make the software more useful (in my opinion).
I hope you can help me.
Best regards,
Jeroen


This post contains more resources

You have to Login for download or view attachment(s). No Account? Register

x
Reply

Use magic Report

14

Threads

1047

Posts

1208

Credits

实习版主

Rank: 7Rank: 7Rank: 7

Credits
1208
Post time 2017-6-15 09:35:44 | Show all posts
Dear sir, thanks for your feedback.

We will test the PP-250 probe and reply you later.

In addition, about the jitter and store a screenshot, please register a username and login to download the latest software on our official website:
http://www.hantek.com/en/ProductDetail_2_10164.html

If the problem exists, please give us a video to study.

1

Threads

5

Posts

5

Credits

新手上路

Rank: 1

Credits
5
 Author| Post time 2017-6-18 06:14:14 | Show all posts
Dear Amy,
Thank you for your reply.
I am curious what your findings are with the PP-250 probe. I installed the latest software and drivers.
regarding the jitter,now I'm not sure if it's trigger related or maybe noise related, today I also noticed a small negative offset which goes away when I connect the unit to mains ground/earth, the jitter stays. If I have time I will make a video.

regards,
Jeroen

14

Threads

1047

Posts

1208

Credits

实习版主

Rank: 7Rank: 7Rank: 7

Credits
1208
Post time 2017-6-22 16:24:00 | Show all posts
Edited by amy at 2017-6-26 13:39

Sir, we have used the keysight oscilloscope MSO-X 3054A and FLUKE5500A multifunction calibrator to test the PP-250 probe.
The input signal is 25MHz and 125MHz @2Vpp.
The test results are as following pictures.



In addition, please give us a picture about your connection mode.



This post contains more resources

You have to Login for download or view attachment(s). No Account? Register

x

14

Threads

1047

Posts

1208

Credits

实习版主

Rank: 7Rank: 7Rank: 7

Credits
1208
Post time 2017-6-28 16:55:42 | Show all posts
We have test the bandwidth of the PP-250 probe, and the bandwidth is greater than 250MHz.



I'm not sure whether there is something wrong with the probe, please give us some pictures of your connection.

This post contains more resources

You have to Login for download or view attachment(s). No Account? Register

x

1

Threads

5

Posts

5

Credits

新手上路

Rank: 1

Credits
5
 Author| Post time 2017-7-5 01:26:04 | Show all posts
Dear Amy,

Thank you for the follow-up. I don't have the expensive equipment you used for your tests, all I have is a DIY 125MHz square wave generator and a 20MHz Siglent function generator. Not having the proper equipment I wouldn't dare to compare my findings to the ones of your set-up.
To be honest, I don't use the Hantek scope any more. I was frustrated with so many little things (mostly software related) and I lost confidence in my measurements,  I decided to buy a Rigol hardware oscilloscope and haven't really looked at the Hantek any more. I hope someday it will improve and better (maybe third party) software will become available.
This USB-scope is not much cheaper than its hardware equivalent so I would expect it to do more and have more features and have a better interface than a normal hardware oscilloscope.

Best regards,
Jeroen

14

Threads

1047

Posts

1208

Credits

实习版主

Rank: 7Rank: 7Rank: 7

Credits
1208
Post time 2017-7-7 14:49:13 | Show all posts
Sir, we are trying to verify the bandwidth of the probe.
But we can't judge whether your probe's bandwidth is not enough or it's out of order.
So we would like to see your connection method.

1

Threads

5

Posts

5

Credits

新手上路

Rank: 1

Credits
5
 Author| Post time 2017-7-13 05:46:10 | Show all posts
Dear Amy,
Thank you for your and coworkers diligence, that is a big plus in my book.
The original test I did was based on only one probe, the first I unpacked after I received the oscilloscope, and it appears it was the that probe that was damaged. I conclude this because the first probe doesn't let any signal through now, it is completely dead now. I tested the other probe and compared them to my other 300MHz probes and this one seems to work fine (with a small voltage deviation and being a bit microphonic), the green trace in the first image. In hind sight, I should have tested both probes before I contacted you, I'm sorry about that. In my defence it was a bit of a weird problem with a signal coming through, but just not very good, before it completely died on me. If you want I can take it apart to find where the malfunction occurred?
I included some pictures, the first picture shows a screenshot of the measured signals of a 150MHz(red), two 300MHz(gray and blue) probes and the working PP250 probe (green), the others show the working PP250 and the broken PP250 with a bit of the measurement set-up ( the yellow traces on the screen).

Best regards,
Jeroen

This post contains more resources

You have to Login for download or view attachment(s). No Account? Register

x

1

Threads

5

Posts

5

Credits

新手上路

Rank: 1

Credits
5
 Author| Post time 2017-7-17 02:22:40 | Show all posts
Dear Amy,
Today I took apart the broken probe and I noticed a couple of things. First, on the PCB near the BNC a white capacitor(?) is broken, it is sheared just before the end cap, I couldn't measure any capacitance or resistance on it. And second, the connection is lost in the cable, between the board which connects to the BNC and the connector which attaches to the probe part. The probe part itself is fine.
I did my best to make it clear on the pictures I attached, if you want to see more or have any questions just ask.

Best regards,
Jeroen

This post contains more resources

You have to Login for download or view attachment(s). No Account? Register

x

1

Threads

3

Posts

3

Credits

新手上路

Rank: 1

Credits
3
Post time 2018-3-18 06:31:40 | Show all posts
I got exactly the same problem in both probes I got with my scope. It seems the Hantek probes break at random inside of the cabling, the wire inside the co-axial cable is broken off. This means the probe is useless because the bandwidth will depend on the parasitic capacitances caused by the platstic between the inner wire and the outer ground wire, but the inner wire is broken off, inside the cable.
12Next
Return to list New
You have to log in before you can reply Login | Register

Points Rules

QQ|Dark room|Mobile|Archiver|Electronic Engineer Discuss

2018-10-17 22:38 GMT+8 , Processed in 0.373908 second(s), 21 queries .

Powered by Discuz! X3.2

© 2001-2013 Comsenz Inc.

Quick Reply To Top Return to the list