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Review: Hantek DDS 3X25. Anyone own one?
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marmad:
I've been reading with interest this thread because I've been thinking about buying either the Hantek DDS-3X25 or the Velleman PCGU 1000 - they are currently the best bang-for-the-buck AWGs available - and they cost close to the same amount from my location (~€102 vs ~€126).

The Velleman seems more stable, has less distortion, better resolution, galvanic isolation of the USB, and a bigger waveform sample depth than the Hantek (8KSa vs 4KSa) - but it's lacking the external trigger in, frequency counter, or ARB Express file compatibility - and it's waveform editing software is primitive.  The Hantek has a much higher frequency range, the aforementioned I/O and file compatibility, and it can work independently of the PC (which might be useful) - but it appears more buggy, and it seems to have a rather crappy set of programming functions and procedures.   It's important to me that I'll be able to write functional software for which ever I buy - I need to create Bode Plotter software with it and the DS1052E.

I guess I'm asking any owners of the DDS-3X25 in general what their current feelings are about the Hantek - and Mechatrommer in particular about the pains of programming it - e.g. it doesn't appear to even have functions for turning the DDS generator on and off - or for elegantly handling sweeps.

BTW, if any current owners of the Hantek have not downloaded Tektronix's free waveform editing software (http://www.tek.com/products/signal-generator/arbexpress.html) - you should get it immediately.  It's MUCH better than what Hantek provides you - and because Hantek uses Tektronix's ARB format - you can easily create waveforms in it (keeping the sample depth below 4096, Vpp below 3.5, and export as CSV) and read them directly into Hantek's software (and AWG).  It also comes with a great library of predefined waveforms as well.

Edit: The link to the actual download page of Tektronix's software: http://www2.tek.com/cmswpt/swdetails.lotr?ct=SW&cs=sap&ci=17700&lc=EN
Mechatrommer:

--- Quote from: marmad on July 08, 2011, 02:33:48 am ---I guess I'm asking any owners of the DDS-3X25 in general what their current feelings are about the Hantek - and Mechatrommer in particular about the pains of programming it - e.g. it doesn't appear to even have functions for turning the DDS generator on and off - or for elegantly handling sweeps.

--- End quote ---
the pain? the pain is in learning programming language and how much complexity of your software, nothing to do with the device. i programmed in VB for this particular application. turning the DDS generator on and off? with little hack in function calls and parameters, you can set DDS to off (no signal), its in my so called "Open Source" link earlier (Halt Button). elegantly handling sweeps? this is yet to be studied. my current method is not elegant due to no available device api function that do this specifically/directly. or maybe thats the limitation in software, hardware, fpga or the dds awg design that we cannot do much about it.
marmad:

--- Quote --- the pain is in learning programming language and how much complexity of your software, nothing to do with the device.
--- End quote ---

@Mechatrommer - well, learning a language is certainly the bulk of the work... but certain devices can be a headache when trying to get them to perform certain functions.  I program a lot of devices - many of them of my own design - and even some of them can be a pain in the ass.  ;D


--- Quote ---my current method is not elegant due to no available device api function that do this specifically/directly. or maybe thats the limitation in software, hardware, fpga or the dds awg design that we cannot do much about it.
--- End quote ---

Yes, I've studied the API calls - though I don't have a DDS-3X25 to try them on - and it seems that there's no way to know exactly where the FPGA is in the sample memory - which could lead to glitches when changing frequency.  The Velleman AWG has the procedure: SetSweep(freq1, freq2, ampl, offset, time, form) to avoid this problem.  But the English in the Hantek manual is terrible, so it's sometimes not easy to know exactly how a procedure works without a device to test it on.  But I'm studying your source code now for more info.  :)

Selamat malam  -  Mark
saturation:
Some side comments.

The Hantek is disappearing, so get it while you can.  Last I checked gone are vendors from EU, America, and what was 2-3 pages of product listing is down to just 3 sellers, all now in China.

Since Velleman has more software tools listed, and they have been demonstrably good in responding to their product issues such as posted on eevblog,  your chances are good of getting tech support from them as you write your software; support is unlikely from Hantek, given too, the device is probably off production.

https://www.eevblog.com/forum/index.php?topic=2885.0

I've had trouble with ArbExpress; for a time Tek changed the arb file format many times but they didn't change the file extension.  So what version works and is compatible is unknown.  Its easier to use the CSV format.

The Velleman is 2 MHz, the Hantek is at 20 MHz.  See rf-loop post on the 'flatness' of the spectrum, suggests there are minimal sine harmonics to 3 MHz to be on par with the Velleman for say, audio work, to compare with Velleman, were a tests has it it clean to ~ -90dB.

http://forum.velleman.eu/viewtopic.php?f=11&t=2041

https://www.eevblog.com/forum/index.php?topic=2170.msg50564#msg50564



--- Quote from: marmad on July 08, 2011, 02:33:48 am ---I've been reading with interest this thread because I've been thinking about buying either the Hantek DDS-3X25 or the Velleman PCGU 1000 - they are currently the best bang-for-the-buck AWGs available - and they cost close to the same amount from my location (~€102 vs ~€126).

The Velleman seems more stable, has less distortion, better resolution, galvanic isolation of the USB, and a bigger waveform sample depth than the Hantek (8KSa vs 4KSa) - but it's lacking the external trigger in, frequency counter, or ARB Express file compatibility - and it's waveform editing software is primitive.  The Hantek has a much higher frequency range, the aforementioned I/O and file compatibility, and it can work independently of the PC (which might be useful) - but it appears more buggy, and it seems to have a rather crappy set of programming functions and procedures.   It's important to me that I'll be able to write functional software for which ever I buy - I need to create Bode Plotter software with it and the DS1052E.

I guess I'm asking any owners of the DDS-3X25 in general what their current feelings are about the Hantek - and Mechatrommer in particular about the pains of programming it - e.g. it doesn't appear to even have functions for turning the DDS generator on and off - or for elegantly handling sweeps.

BTW, if any current owners of the Hantek have not downloaded Tektronix's free waveform editing software (http://www.tek.com/products/signal-generator/arbexpress.html) - you should get it immediately.  It's MUCH better than what Hantek provides you - and because Hantek uses Tektronix's ARB format - you can easily create waveforms in it (keeping the sample depth below 4096 - and the Vpp below 3.5) and read them directly into Hantek's software (and AWG).  It also comes with a great library of predefined waveforms as well.

Edit: The link to the actual download page of Tektronix's software: http://www2.tek.com/cmswpt/swdetails.lotr?ct=SW&cs=sap&ci=17700&lc=EN

--- End quote ---
Mechatrommer:

--- Quote from: marmad on July 08, 2011, 01:30:45 pm ---but certain devices can be a headache when trying to get them to perform certain functions.  I program a lot of devices - many of them of my own design - and even some of them can be a pain in the ass.  ;D

--- End quote ---
from my experience working with 3x25, its painless. every functions do what they suppose to do. its just tinkering on how to make the dds "OFF" in software, you need to find out the indirect way (several api calls), because there is no direct way. and there's no SetSweep function like you said, it will be alot more painless if it is.

about the code. maybe you need some effort digging the functions call in my code. the simpler explanation is to send "zero valued" (volt) data to DDSDownload and then call the DDSSetSingleWave (not compulsory). if you want something about pain. DDSSetSingleWave is the most painfull function to call, i dont know what it does, its just stop the device from outputting data (which i was expecting it to output a "one time/once" data from the name.

and my "not elegant" method in sweeping is by repeatedly calling DDSSetFrequency and DDSDownload, that also can be a pain, depending on your definition of "pain".
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