DSO4072c AFG AM modulation frequencies

pavlenkoa

wangshuang replied at 2020-5-23 14:44
New firmware has been released, you can download corresponding file in Hantek website:
http://hant ...

Good afternoon!
On this topic, the new firmware practically did not fix anything. The only thing that is fixed is that the carrier frequency is now not divided in half.
Below are screenshots that show that the carrier frequency is shifted relative to the frequency deviation set by the value. I ask developers to finally study what the spectrum of the FM signal looks like! Why are we doing this here? This is a school? Why are they relentlessly releasing a product unsuitable for work ?! I was hoping that a couple of frames in the previous posts would be enough to understand what was going on.









This is what the spectrum of the fm signal should look like.
This is how it looks on my oscilloscope DSO4102c , but from an external generator.



And further. I wrote in a neighboring post about the terrible color scheme of the themes of this device. No one answered me. Can you really make out the line at the bottom of the screen? I assure you - on the screen it reads even worse than this screenshot. Perhaps this gives joy to the developers so, I’m not afraid of it, to mock buyers?
Give us the opportunity to redefine the colors in the theme ourselves! It's horrible! Is it really not visible ?!



I want to apologize to those who may have offended my words, but I can no longer tolerate. I purchased your device for work, but I'm starting to regret it .....

wangshuang

pavlenkoa replied at 2020-5-21 16:32
Please give and on dso4102c .........
The problem is the same.

New firmware has been released, you can download corresponding file in Hantek website:
http://hantek.com/en/ProductDetail_3_4163.html

pavlenkoa

wangshuang replied at 2020-5-21 11:42
Please use this firmware to do measurement.
https://fil.email/PmZozBWb

Please give and on dso4102c .........
The problem is the same.

wangshuang

Please use this firmware to do measurement.
https://fil.email/PmZozBWb

pavlenkoa

wangshuang replied at 2020-5-12 10:31
The manual is wrong, F0 is the modulation frequency, Freq is the carrier frequency, and MaximFreq ...

Good afternoon! The error in the manual was understandable even earlier, but how do you explain the discrepancy between the output signal and the values set in the menu?
As you can see above, I set the carrier frequency to 20 kHz. Modulation frequency 1 kHz. And what do we see at the output of the generator? The carrier frequency decreased by half and shifted by the magnitude of the modulation frequency. She became equal to 11 kHz !!!f I set the modulation frequency to 0, then the carrier frequency at the output is half the set frequency, namely 10 kHz.

Below I posted a picture from another external generator with the same signal parameters - everything is fine there!

wangshuang

The manual is wrong, F0 is the modulation frequency, Freq is the carrier frequency, and MaximFreq is the FM deviation.

pavlenkoa

Do the developer representatives see our comments?
5 days have passed - no reaction.
We did not write about impressions about the oscilloscope - we wrote about a really idle generator sold to us under the guise of working!
Where are the answers?

pavlenkoa

FSC replied at 2020-4-28 15:38
I agree that it might "only" be a documentation/naming issue. But what really bugs me is that the di ...

What kind of correspondence are you talking about ?! THIS IS NOT ALLOWED TO BE USED! Compare the set carrier frequency and the spectrum readings on the first two frames. Then I added modulation. I wish I didn’t! New laws of radio technology.





Куда уплыла несущая?
Что это? Это генератор?


Where did the carrier go?
What is it? Is this a generator?





IN THIS TYPE IT IS IMPOSSIBLE TO SELL. PLEASE READ THE TIME WHICH IT IS PERFORMING!
DSO4102c

p.s.
By the way, here's how an external generator FY6900 works with the same parameters. Pay attention to the carrier frequency - it does not move anywhere and is equal to exactly 20 kHz.
See the difference !!!!!
Although I have DSO4102c, but I think the generator we wrote the same programmer. (He was in a hurry somewhere and did not check much that he wrote - there are still bugs for several posts).
There is no time for jokes.
They sell an appliance that cannot be used.
I really ask the developers to respond and fix all the errors, although it costs us nerves.



Model: DSO4102C
sw version: 3.50.0(200410.0)
hw version: 1020xffffa000

FSC

I agree that it might "only" be a documentation/naming issue. But what really bugs me is that the displayed signal is not what the output is. I set the parameters according to "common" understandig (and the documentation), hope that the values are applied and get a signal displayed that looks correct but the output differs...
Similar issues apply (as you said) to the FM.

Best regards
Florian

pavlenkoa

I believe that everything is correct in the device, and the error is contained in the instruction, where F0 was erroneously called the carrier frequency. Look - everything is logical on the first page of the generator we set the carrier frequency of the generator, and the second - the type of modulation, and then either the modulation frequency or the deviation frequency. It would be strange to first select the modulation frequency on the first page. They really messed up the names. On the first page, the carrier really needs to be called F0, and on the second page, Fmod and Fdev, respectively. Let them fix it. There are still many shortcomings in the generator. Later I want to describe those that I found.
DSO4102c.