Products > Test Equipment
Hantek HDG2002B AWG: 5Mhz or 100MHz? Let's see!
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markone:

--- Quote from: robert_ on February 08, 2016, 09:58:48 pm ---Also i did not pay anything even near the 25k for the HRO.

--- End quote ---

At the time was the street price with some sw options, it was a demo, at the end was not purchased..., so i guess your is from second hand market.
TurboTom:
Thanks Robert -

I already got the voltage supply stuff sorted, that was rather simple. I only didn't use an adjustable LT1117 for the 1.8V supply  -- I found a fixed version in my "salvage box" and rather removed the divider network on the HDG PCB. I also did some further testing on the U14 data direction issue and came to a different conclusion: It's got to be an ADuM2402 / 3402 version with two channels in each direction. I came to this result for two reasons: Firstly, it makes no sense to use two different components for U13 and U14 to provide a single additional channel in the Control -> Signal section direction if there's one such channel unused on the other (U14) isolator. Every half-way sane electronics designer (if this doesn't mutually exclude each other  :-DD ) would use identical parts to keep BOM diversity low and get better prices by sourcing higher quantities of individual components. So in this case, two ADuM2400 / 3400 would have been the way to go (that's what I initially thought without taking a closer look). Secondly, I probed the data direction by injecting a small current (via a multimeter in diode test mode) across the damping network RA8 (fortuantely, there are test pads available). And this test gives clear evidence that the signals on Tp27 and TP28 are driven from the control section.

Yet, when playing with the generator (toy...) I've never seen any activity on the line connected to Tp27 which may explain why your setup works perfectly well with the ADuM3401 isolator.

In general, I agree with what's been said here ragarding the value of the whole gadget - for economic reasons, it's not worth throwing any effort/money after the thing, it's basically crap. With a half-way decent firmware/software package it had some potential but this will most probably never happen. Anyway, I just enjoy playing with it and poking around. If I make a mistake, it wouldn't mean a considerable loss and on the other hand, it works well enough to replace my existing, simple DDS generator. So I simply consider it a toy, no more, no less.

Cheers,
Thomas
markone:

--- Quote from: TurboTom on February 09, 2016, 09:55:02 am ---So I simply consider it a toy, no more, no less.

--- End quote ---

If it wasn't  that Robert spotted an unsafe PSU inside the toy ... i could agree with you.

When i saw his warning post i trusted him and fearing to put in jeopardy myself and all attached devices i returned the toy in its cardbox, afterwhile i went for the SDG2042X.

It costed me 550 Euro but  it works a treat and it's worth every Euro spent, conversely the toy was a total wast of money and time.

Anyway, now i'm under the impression that most people that bought the HDG2002B used it only as single tone generator, meanwhile not being able to understand that all the rest do not work or work bad. 
TurboTom:
Markone - actually my HDG doesn't seem to be that bad (H/W 1004.1, S/W 1.00.3.03.05, FPGA 42). After calibration, amplitude flatness is acceptable (of course wide-range sweeps are a different thing), Modulation works, dual output no problem. "Real" arbitrary and PC-based functions are a joke and unusable but the internal "arbitrary" functions work okay as well. In "everyday's use" it hardly crashes. The PSU is a different story but as I understood there have to be at least two different versions around (those with the separate 5V supply and those without). I've got the same version as Robert has (without the separate 5V output) and I agree with him that it's quite a bad design. But I did a high-pot test on it up to 2.5kV and didn't find any problems. So, for the time being I use it but will replace it eventually with a home-brewn one with a toroidal transformer (similar to Robert's approach). What I added is a 40V bidirectional 4kA suppressor diode between output ground and earth. This limits the voltage coupled through the capacitor across the transformer and will also provide a little more safety in case of a catastrophic failure of the power supply while still keeping the output ground floating for all practical means. So as a toy for hobby use, it appears just acceptable to me, especially considering the price.

Cheers,
Thomas
markone:

--- Quote from: TurboTom on February 10, 2016, 08:20:07 am ---But I did a high-pot test on it up to 2.5kV and didn't find any problems. So, for the time being I use it but will replace it eventually with a home-brewn one with a toroidal transformer (similar to Robert's approach). What I added is a 40V bidirectional 4kA suppressor diode between output ground and earth. This limits the voltage coupled through the capacitor across the transformer and will also provide a little more safety in case of a catastrophic failure of the power supply while still keeping the output ground floating for all practical means. So as a toy for hobby use, it appears just acceptable to me, especially considering the price.

Cheers,
Thomas

--- End quote ---

That's good Thomas, safety first !

I assume that last FW works good with your PCB version (1004.1), with mine (1004) it utterly brokes any signal modulation function, so i had to revert.
Just out of curiosity, if you can try AM 1Khz 100%/ FM 5Khz 500Hz dev modulation on 1-20Mhz sine carrier and let me know.

It could be also feasable to supply the toy with a small isolation transformer, just to not to have the live power line inside the box and eventually on the output BNCs.

Anyway if i wer to replace the internal PSU i would go for a linear unregulated stage (transformer/ diode bridge / cap) plus a bunch of Traco DC/DC converters, or even better for a 19V laptop external PSU and inside again a bunch of  bla bla bla.

But this would mean additional time / money outgoings for a toy that is kidding me most of the time, and looking how good (or how normally ?) works my SDG2042X, i definitely think to have thrown every Euro spent for HDG2002B out of a running car's window .

Marco.
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