Author Topic: Which scope below $300 has best. FFT function  (Read 1984 times)

0 Members and 1 Guest are viewing this topic.

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10790
  • Country: 00
Re: Which scope below $300 has best. FFT function
« Reply #25 on: June 02, 2020, 03:18:21 pm »
Does the GDS1054B have serial decode and triggering?

It does if you copy the relevant firmware modules onto the internal storage.  :)

It's a modular firmware system and you can copy modules from higher-up Instek models onto lower-down models.

https://www.eevblog.com/forum/testgear/possible-gw-instek-gds-1000b-hack/

They also have 4 channels (with per-channel controls) and a proper push button next to the twisty knob - no more pushing twisty knobs to select things.

« Last Edit: June 02, 2020, 03:24:13 pm by Fungus »
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10790
  • Country: 00
Re: Which scope below $300 has best. FFT function
« Reply #26 on: June 02, 2020, 03:22:13 pm »
Really, Fungus links a 4 year old video on FFT shootout and thinks it's relevant to todays offerings ?  ::)  :horse:

What's changed since that video?

(...apart from the Rigol DS1054Z getting a firmware update to do FFT from memory instead of "screen")

 

Online TK

  • Super Contributor
  • ***
  • Posts: 1495
  • Country: us
  • I am a Systems Analyst who plays with Electronics
Re: Which scope below $300 has best. FFT function
« Reply #27 on: June 02, 2020, 03:25:35 pm »
Does the GDS1054B have serial decode and triggering?

It does if you copy the relevant firmware modules onto the internal storage.  :)

It's a modular firmware system and you can copy modules from higher-up Instek models onto lower-down models.

https://www.eevblog.com/forum/testgear/possible-gw-instek-gds-1000b-hack/
They also have 4 channels (with per-channel controls) and a proper push button next to the twisty knob - no more pushing twisty knobs to select things.
It is now included standard (official) with the latest firmware update
 
The following users thanked this post: edavid, Fungus

Online TK

  • Super Contributor
  • ***
  • Posts: 1495
  • Country: us
  • I am a Systems Analyst who plays with Electronics
Re: Which scope below $300 has best. FFT function
« Reply #28 on: June 02, 2020, 03:29:35 pm »
Does the GDS1054B have serial decode and triggering?

It does if you copy the relevant firmware modules onto the internal storage.  :)

It's a modular firmware system and you can copy modules from higher-up Instek models onto lower-down models.

https://www.eevblog.com/forum/testgear/possible-gw-instek-gds-1000b-hack/

They also have 4 channels (with per-channel controls) and a proper push button next to the twisty knob - no more pushing twisty knobs to select things.
I am waiting for my unit to arrive to test if the hack still works with the latest firmware.  I had one in the past and I was able to downgrade to a firmware that supported the hack, then you can upgrade from there.  In theory you can hack to 200MHz and I remember measuring signals all the way up to 300MHz or above
 

Offline khutch004

  • Contributor
  • Posts: 5
  • Country: us
Re: Which scope below $300 has best. FFT function
« Reply #29 on: June 02, 2020, 06:23:13 pm »
Quote from: Fungus link=topic=243619.msg3086244#msg3086244 date=1591076169
The GW-Instek is similarly priced to your Siglent but does a much better job.
[/quote

If the GW-Instek is priced similarly to the Siglent then neither are under $300 are they? My point was that if good FFT performance is important to you then you should be willing to spend what it takes to get it. I don't care which brand and model of scope anyone else here buys. But it is better to spend $360 on something that satisfies you than $285 on something you will use for a while and then replace with what you should have bought in the first place. The Siglent I bought met several requirements that I had, not just good FFT performance. But the FFT performance is quite good enough for my needs. If some other brand/model suits you better I am neither surprised nor offended by that. If something else had suited me better I would have bought it instead. This was my first Siglent purchase, I have no emotional attachment to them.
 

Online jjoonathan

  • Frequent Contributor
  • **
  • Posts: 421
  • Country: us
Re: Which scope below $300 has best. FFT function
« Reply #30 on: June 02, 2020, 07:14:02 pm »
Ooh, good catch! The GW Instek is in a completely different FFT league from the rigol and siglent.
:-DD
Yep, Dave hated it.

Really, Fungus links a 4 year old video on FFT shootout and thinks it's relevant to todays offerings ?  ::)  :horse:
Are siglent's current entry-level scope FFTs still this bad:

https://youtu.be/Cwbwq-AKbPc?t=475

?
 

Online 2N3055

  • Super Contributor
  • ***
  • Posts: 2541
  • Country: hr
Re: Which scope below $300 has best. FFT function
« Reply #31 on: June 02, 2020, 07:42:26 pm »
Ooh, good catch! The GW Instek is in a completely different FFT league from the rigol and siglent.
:-DD
Yep, Dave hated it.

Really, Fungus links a 4 year old video on FFT shootout and thinks it's relevant to todays offerings ?  ::)  :horse:
Are siglent's current entry-level scope FFTs still this bad:

https://youtu.be/Cwbwq-AKbPc?t=475

?

No.
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10790
  • Country: 00
Re: Which scope below $300 has best. FFT function
« Reply #32 on: June 02, 2020, 07:48:16 pm »
If the GW-Instek is priced similarly to the Siglent then neither are under $300 are they?

What if it's only $310?

https://www.tequipment.net/Instek/GDS-1054B/Digital-Oscilloscopes/?search=true

 

Online nctnico

  • Super Contributor
  • ***
  • Posts: 19654
  • Country: nl
    • NCT Developments
Re: Which scope below $300 has best. FFT function
« Reply #33 on: June 02, 2020, 08:18:02 pm »
And don't forget the Tequipment EEVblog discount. Don't know how much it is exactly but 5% already takes the GDS-1054B below $300.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online TK

  • Super Contributor
  • ***
  • Posts: 1495
  • Country: us
  • I am a Systems Analyst who plays with Electronics
Re: Which scope below $300 has best. FFT function
« Reply #34 on: June 02, 2020, 08:38:51 pm »
And don't forget the Tequipment EEVblog discount. Don't know how much it is exactly but 5% already takes the GDS-1054B below $300.
Don’t tell me they also have EEVblog discount!  Well, little bit late for me but good news anyway
 

Online rsjsouza

  • Super Contributor
  • ***
  • Posts: 3875
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Which scope below $300 has best. FFT function
« Reply #35 on: June 02, 2020, 08:50:31 pm »
Ooh, good catch! The GW Instek is in a completely different FFT league from the rigol and siglent.
:-DD
Yep, Dave hated it.

Really, Fungus links a 4 year old video on FFT shootout and thinks it's relevant to todays offerings ?  ::)  :horse:
The FFT on the Instek looks alright, but the interface is terrible with having to go back and forth on the buttons to change the center, span and magnitude. I can see why he hated it; I would as well.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Online nctnico

  • Super Contributor
  • ***
  • Posts: 19654
  • Country: nl
    • NCT Developments
Re: Which scope below $300 has best. FFT function
« Reply #36 on: June 02, 2020, 08:53:07 pm »
Once you get the hang of it, it is actually is quite productive for doing real measurements. I've used my GW Instek scope's FFT function extensively during the development of a project a couple of years ago.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline gfmucci

  • Regular Contributor
  • *
  • Posts: 74
  • Country: us
Re: Which scope below $300 has best. FFT function
« Reply #37 on: June 07, 2020, 01:02:30 am »
That is the Analog discovery.

FFT length is important to get a high frequency resolution. More bits means more dynamic range.

I don't have an extra computer to devote to the bench and not another $1K for one, so no Discovery 2. 

And yes, use is for audio frequency, distortion testing and diagnostics.   The newish Rigol DS 1202Z ($299; ~$30 less than current Intek previously mentioned) has 24M bit depth which I thought would help with fft.
 

Online TK

  • Super Contributor
  • ***
  • Posts: 1495
  • Country: us
  • I am a Systems Analyst who plays with Electronics
Re: Which scope below $300 has best. FFT function
« Reply #38 on: June 07, 2020, 02:00:48 am »
FFT on Rigol is bad. The GDS1054B is less than $300 if you apply the eevblog coupon. The 24Mpts does not help with FFT
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10790
  • Country: 00
Re: Which scope below $300 has best. FFT function
« Reply #39 on: June 07, 2020, 04:02:52 am »
And yes, use is for audio frequency, distortion testing and diagnostics.   The newish Rigol DS 1202Z ($299; ~$30 less than current Intek previously mentioned) has 24M bit depth which I thought would help with fft.

The FFT on that series of Rigols is awful, limited to 64k points and terrible UI. Do not buy one if "use is for audio frequency, distortion testing and diagnostics".

(if that really is the main use for this then get an Analog Discovery instead, it has 14-bit ADC for much lower noise floor and built-in signal generator for bode plots)

« Last Edit: June 07, 2020, 07:34:23 am by Fungus »
 

Online TK

  • Super Contributor
  • ***
  • Posts: 1495
  • Country: us
  • I am a Systems Analyst who plays with Electronics
Re: Which scope below $300 has best. FFT function
« Reply #40 on: June 07, 2020, 07:22:54 am »
DS1000Z vs GDS-1054Z FFT comparison video

 

Offline Gandalf_Sr

  • Super Contributor
  • ***
  • Posts: 1632
  • Country: us
Re: Which scope below $300 has best. FFT function
« Reply #41 on: June 07, 2020, 10:29:44 am »
Yes the GW Instek GDS-1054Z has a 'better' FFT than the Rigol DS1054Z but the UI on the GDS-1054Z is "Ugh" according Dave Jones' video comparing many O'scope brands.



It's like asking which is the better 50" TV to buy when I have only $50 to spend.

My point being that, if you really want to do FFT, you'd be better bumping up your budget to the $600 - $900 range.

If you really want to do spectrum analysis, buy a spectrum analyzer.
« Last Edit: June 07, 2020, 10:31:46 am by Gandalf_Sr »
If at first you don't succeed, get a bigger hammer
 

Online nctnico

  • Super Contributor
  • ***
  • Posts: 19654
  • Country: nl
    • NCT Developments
Re: Which scope below $300 has best. FFT function
« Reply #42 on: June 07, 2020, 10:38:07 am »
Yes the GW Instek GDS-1054Z has a 'better' FFT than the Rigol DS1054Z but the UI on the GDS-1054Z is "Ugh" according Dave Jones' video comparing many O'scope brands.
The UI on the GW Instek isn't that bad. It is just compact with dual function keys in order to minimize the number of menus to go through. And nowadays GW Instek has a spectrum analysis mode as well.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10790
  • Country: 00
Re: Which scope below $300 has best. FFT function
« Reply #43 on: June 07, 2020, 11:07:27 am »
Yes the GW Instek GDS-1054Z has a 'better' FFT than the Rigol DS1054Z but the UI on the GDS-1054Z is "Ugh" according Dave Jones' video comparing many O'scope brands.

He also said, "...ultimately, it can do the business".
 

Offline Gandalf_Sr

  • Super Contributor
  • ***
  • Posts: 1632
  • Country: us
Re: Which scope below $300 has best. FFT function
« Reply #44 on: June 07, 2020, 12:22:53 pm »
I'm not bashing GW Instek and I'm certainly not saying that the DS1054Z has a usable FFT; I watched the video and I see why Dave described the UI controls for the FFT function on the GDS-1054Z as "Ugh".  This has fired me up to go into my mancave and test out the FFT FUNctionality of my Rigol MSO5074.

[EDIT] I repeated Dave's FFT test on my MSO5074 and it works like a dream...
« Last Edit: June 07, 2020, 01:33:56 pm by Gandalf_Sr »
If at first you don't succeed, get a bigger hammer
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10790
  • Country: 00
Re: Which scope below $300 has best. FFT function
« Reply #45 on: June 07, 2020, 02:01:33 pm »
[EDIT] I repeated Dave's FFT test on my MSO5074 and it works like a dream...

Not exactly "below $300" though.

If we're going to be strict about the competition rules then here's a signal with four harmonics being shown on my DSO Quad:



It updates at full screen rate. It also has a built-in signal generator and can do Bode plots. They cost about $160.  :)


nb. The signal is coming from a digital pin on an Arduino going into an RC filter so S:N ratio is about 48dB.
« Last Edit: June 07, 2020, 02:04:33 pm by Fungus »
 

Offline Gandalf_Sr

  • Super Contributor
  • ***
  • Posts: 1632
  • Country: us
Re: Which scope below $300 has best. FFT function
« Reply #46 on: June 07, 2020, 02:31:02 pm »
What's a DSO Quad? The graphics look like an old Pong machine.
If at first you don't succeed, get a bigger hammer
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10790
  • Country: 00
Re: Which scope below $300 has best. FFT function
« Reply #47 on: June 07, 2020, 02:51:26 pm »
 

Offline gfmucci

  • Regular Contributor
  • *
  • Posts: 74
  • Country: us
Re: Which scope below $300 has best. FFT function
« Reply #48 on: June 07, 2020, 03:34:15 pm »
Yes the GW Instek GDS-1054Z has a 'better' FFT than the Rigol DS1054Z but the UI on the GDS-1054Z is "Ugh" ...

My point being that, if you really want to do FFT, you'd be better bumping up your budget to the $600 - $900 range.

If you really want to do spectrum analysis, buy a spectrum analyzer.

When I receive your $500 check in the mail, I'll consider your recommendation.  Even then I might use the $500 to pay next month's mortgage. 

As for 55" tv's, I got a perfectly fine one for $350 a few months ago.  And yes, if I wanted to be a tv elitist, I know I could spend over a few grand.  I find that some have the same view of scopes.

Consider me in the Fungus camp, or even a few levels below.  I have seen videos by audio techs using their scope to measure >0.1% amplifier harmonic distortion using scopes rated fairly poorly for their fft function.
https://youtu.be/n8hNrDcJMCw

I was looking for something that is considered the top of the heap with regard to fft, maybe a little or somewhat better than what the audio guy was using for under $300.  It looks like the GW Instek fits the bill, with the only downside being a little more knob fiddling being required. 

Thanks for the recommendations.  The GW will be added to my  "maybe" list.
« Last Edit: June 07, 2020, 03:48:44 pm by gfmucci »
 

Online Mr. Scram

  • Super Contributor
  • ***
  • Posts: 9217
  • Country: 00
  • Display aficionado
Re: Which scope below $300 has best. FFT function
« Reply #49 on: June 07, 2020, 03:39:43 pm »
I've seen a DS1054Z used to pipe data to a PC for FFT a long time ago and I've been surprised this isn't much more common. I see some people talking about Matlab or Python here but there doesn't seem to be any common program or method, despite proper spectrum analyzers still being stupidly expensive. Is anyone willing to share their method or setup?
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf