Hantek DDS-3X25 AWG review interest? - Page 1
Forum section: electronics / general

author: EricF
author_rank: Contributor
timestamp: January 09, 2011, 03:33:50 pm
content: There is a small discussion in the General forum regarding the Hantek DDS-3x25 PC based waveform generator that is available on ebay for around 150 dollars US. If there is enough interest, I would be willing to buy one so that Dave (if he would be willing) could review it as to its usefulness for a home lab. Anyone else interested in having this reviewed?EricF

author: saturation
author_rank: Super Contributor
timestamp: January 09, 2011, 05:02:50 pm
content: Of course me, EricF! I've spoken to one dealer and 'made an offer' for $140, so I'll have it in a week.I'm getting one not so much for the quality of the frequency response, but to simulate digital waveforms, like PWM, serial data outputs etc., and since there is no other AWG remotely close to its capacity at this price point. Its really an AWG for the hobbyist/home lab person for anyone working to 25MHz, maybe to 75MHz, as per its spec.I don't think it will replace the Instek 1003 in terms of quality waveforms, but it makes up for its what the 1003 can not do while providing an AWG capacity, such as modulation, sweeping, if you need it.

author: EricF
author_rank: Contributor
timestamp: January 11, 2011, 01:04:38 am
content: Given whats going on in the General chat regarding this device, I think I will wait for another product for review...EricF

author: saturation
author_rank: Super Contributor
timestamp: January 11, 2011, 01:07:32 pm
content: All is not lost! As I suggested in my post, frequency response quality willbequestionable. Issues with the waveform response is to be expected. What need be found is how good, or how bad?Hantek has an "upgraded" DDS 3005 5MHz USB DDS AWG for 2x the cost of this model, so clearly, there is something going to be unstable in the 3x25, why is a 25MHz rated devicecheaper?; dajones evaluation at least suggests its stable to 2.5 MHz. There are probably more limitations that aren't in the spec sheet.http://cgi.ebay.com/DDS-3005-USB-PC-Function-Arbitrary-Waveform-Generator-/130313245353?pt=BI_Signal_Sources&hash=item1e574652a9A trick to cheapies is to characterize the device, so you know where it will be useful; don't expect it to live up to the spec sheets but make your own and limit its applications to that level; even the best devices are the same way they all have limitations, you limit its application to where it performs best.As I wrote previously, if you want solid output to 3MHz at low cost, the Instek 1003 doesn't disappoint. If you need an AWG source, there isn't one close to the 3x25, but don't expect the output to be arock stable signal reference.

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 25, 2011, 02:06:50 am
content: Quote from: saturation on January 11, 2011, 01:07:32 pmits a 2.7GHz ondometer, not sure what it is (wavelength measurement), i think more toward frequency counter. maybe thats the reason 2x the cost ot dds 3x25

author: dreschel
author_rank: Contributor
timestamp: March 26, 2011, 02:04:42 am
content: Hi Guys,I own two DDS-3X25s, purchased with the intent of building some test systems. In general I have been happy with the devices (they are easy to talk to in C# 2010 Express) but I have run into one problem which is driving me nuts. When I try to run these in Single Wave mode with an external trigger, they drop probably 1% to 5% of the triggers and put out no signal or sync pulse. Both units act the same way. I have a TDS210 and can watch the sync signals randomly fall out, while the trigger-in looks rock steady (5V, fast transition).The trigger rate does not seem to matter (I have tried from 10Hz to 1 kHz). Is anyone else seeing this? Does anyone have a solution?Thanks in advance.Bill

author: dreschel
author_rank: Contributor
timestamp: March 26, 2011, 02:50:00 pm
content: Here are two scope shots of the DDS-3X25 in Single Wave - External Triggered mode. The 3_2_1_6_software.jpg shows the Hantek DDS-3X25 version 3.2.16 software responding to a trigger (SYNC OUT on top, TRIGIN on bottom). Note both drop outs and 500ns of jitter.The second photo is some software I wrote to do the same thing: SingleWave-External Trigger mode. Note the lack of jitter, but the drop outs. In my software, the drop outs seem an order of magnitude worse than with their software (I don't know how they are setting up the controls, I am using their DLL library for my software functions).Also note that my trigger signal is now only 3V. I reduced it because the photos elsewhere on this site seem to indicate the TRIGIN goes right into the big chip with only an inline resistor. The big chip is supposed to be a Xilinx Spartan 3AN, which has an input absolute max limit of 4.6V.I kinda wish they had mentioned that somewhere in the documentation.

author: torch
author_rank: Frequent Contributor
timestamp: January 15, 2016, 11:58:35 am
content: Quote from: dreschel on March 26, 2011, 02:50:00 pmI realize it has been a few years, but you wouldn't by chance recall the external trigger specifications regarding minimum voltage, frequency and wave form would you? I was attempting a little experiment with mine, can't seem to get it to respond at all to an external trigger (tried various signals from 10MHz sine down to a 10Hz pulse). I'm starting to fear I somehow cooked the input on that "big chip" you mention.

author: dreschel
author_rank: Contributor
timestamp: January 15, 2016, 01:27:19 pm
content: Wow, that has been a few years. I ended up not using the Hantek AWG in the project I was working on because of that annoying drop out problem. I never did find the reason for it, though I suspect it was some race condition not handled well by their drivers and not documented in their "developers manual". As a CW device is worked pretty well.For the trigger I just used a digital square wave, 0 to 3V, divided down from a 0-5V digital output. I think any 74LS, 74HC or 74AHC type drive output will work fine. Sine waves on the trigger will be problematic, as the trigger input goes directly to a digital input... I think the trigger length (time high) needs to be a minimum of several microseconds. I can't remember if you can change polarity.Hope this helps. Since the FPGA input is only buffered by a single resister you may have to worry about ESD damage on that input also.