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Hantek HDG2002B AWG: 5Mhz or 100MHz? Let's see!
Control:Eng:
Hmm...looking at the spectrum...Hantek's design really seems to be imperfect.
This is what the AD9747 is capable of:
http://wiki.analog.com/_detail/resources/fpga/xilinx/interposer/cf_ad9747_ebz_spectrum_1.jpg?id=resources%3Afpga%3Axilinx%3Ainterposer%3Aad9747
Could somebody maybe explain why we get these spurious spectrums?
fremen67:
--- Quote from: idpromnut on May 20, 2014, 11:45:34 pm ---
--- Code: ---./test_bkl on 105
--- End code ---
Poof the display popped back on! Of course on reboot it turned back off again. So after temporarily re-enabling the backlight, I went back into Utility -> System Status -> Startup and set it to Default, power cycled and boom, back in business no worries. :palm:
--- End quote ---
Nice that you discovered that it was related to backlight :)
I also had the same problem but I solved it with the def.hsf file. I should have posted it before but It went out of my mind. I will try again this evening to see exactly how I did.
--- Quote from: idpromnut on May 20, 2014, 11:45:34 pm ---
--- Code: ---./test_bkl on 105
--- End code ---
Well I guess there are still a few bugs in the firmware ::) Please note that you can run into this bug REGARDLESS OF WHETHER YOU CRACK THIS FUNCTION GENERATOR OPEN OR NOT, and it has nothing to do with modifying the HDG2002. Except that if you don't crack it open after you do this, you seemingly have no way to recover. :-//
--- End quote ---
I think we should investigate on how the firmware update process is working (like Tinhead did for DSO5000) so that we can have a way of backing up/restoring files... doing things from the front USB jack or SD slot without opening the enclosure.
Of course in that case it would be difficult to restore things easily that way but for this one, we could at least describe the blind "key push "sequence to follow in order to restore settings (I think we can do it without turning the knob, just with simple keys).
tinhead:
--- Quote from: Control:Eng on May 21, 2014, 07:16:05 am ---Hmm...looking at the spectrum...Hantek's design really seems to be imperfect.
This is what the AD9747 is capable of:
http://wiki.analog.com/_detail/resources/fpga/xilinx/interposer/cf_ad9747_ebz_spectrum_1.jpg?id=resources%3Afpga%3Axilinx%3Ainterposer%3Aad9747
Could somebody maybe explain why we get these spurious spectrums?
--- End quote ---
two things: on the AD board the SMA is connected directly (except transformer) to DDS, so the spectrum will be worse than on Hantek. And of course when you check what setting they used on SA "span 115MHz/RBW 20kHz" then no wonder that there is nothing visible. There is as well clock aspect, AD is using 250MHz clock on that picture, comming directly from "external source", and you can bet they used good and clean source. With good jitter"free" clock the noise floor is for sure better (and less spurious, but whatever there is, it is not visible due the SA settings).
Hantek is using (variable?) clock coming from FPGA (LVDS AC coupled via C191/C187, with DC offset R150/R151). Everything out of FPGA have lot of jitter (minimum 100ps from internal logic pk-pk + pin driver jitter). Such "phase modulated" clock is creating all that spurious and phase noise degradations as shown here:
Of course is Hantek using good clock source for FPGA (a bad source would add additional jitter, overloaded external source as well), and some filtering after all, but one will not get better results when clocking with FPGA (they doing this probably to run variable clocks, however if not then one could add clock jitter attenuator from e.g. Silabs to get rid of that jitter. But of course, that extra 20USD or so, one have not to forget that this is not highend AWG). Sure, everything can be done better, and it has been already done, but if one buy gear for nearly price of the compoenents then please don't expect wonder :)
idpromnut:
@tinhead: nice SA screen caps, thanks for that!
@fremen67: I will take a full back up (manually) tonight and then start poking around. I think the first order of business would be to find a way of booting off either the SD card or the front USB. Perhaps we'll get lucky and it "just works" :-DD
tinhead:
--- Quote from: idpromnut on May 21, 2014, 01:49:02 pm ---@tinhead: nice SA screen caps, thanks for that!
--- End quote ---
they has been made by RFasic, i only re-posting them
https://www.eevblog.com/forum/testgear/hantek-hdg2002b-awg-5mhz-or-100mhz-let's-see!/msg447032/#msg447032
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