I just went through a maddening exercise trying to contact Paypal and eBay who clearly don't want to allow you to contact them except by checkbox forms. It would appear that I shall have to write a paper letter to complain to eBay.
I ordered mine on 20 Nov and first contacted FeelTech on 8 December. I feel fairly certain that the strategy at FeelTech is to stall the user until the Paypal and EBay protections expire.
In the meantime, I've modified my .sig. I should like to suggest that others do similarly. That will spread the word rather widely.
rhb, yeah, it is buried a bit deeply. However, you can call them by navigating as follows:
1. Go to
https://ocsnext.ebay.com/ocs/home2. Click
Contact us button
3. Select
Buying4. Select
Returns5. Select
Returning an item6. At the bottom of the page, click
Call us or
call me button
Can you test this specifically with some frequencies which are whole divisions of the 250mHz clock. Like 50.00, 41.66, 35.71, 31.25, 27.77, 25.00 MHz
I did the measurements at the requested frequencies, a lot more carefully than the previous day's rough look, and took the average over four separate trials, after a 30 minute warm up period. The Ch1 trace was centered exactly on the crosshairs at 25MHz, and the Ch2 lag time was measured at each frequency, the results being:
25.00MHZ 1.00nS
27.77MHz 1.00nS
31.25MHZ 1.10nS
35.71MHz 1.00nS
41.66MHz 1.10nS
50.00MHz 1.20nS
In fact, the relative phase shift was constant from at least 5Mhz to 50MHZ, but both traces kick laterally by about 2nS at 20MHz - otherwise their positions are quite stable.
One thing I did notice today, however, is that the Ch2 amplitude is about 0.15v less than Ch1's when set to 5v at 25MHz, when the channels are supposed to be in sync, and the difference appears to get bigger as the frequency increases. I'll have to have another look at that to see exactly whats going on over the whole range, and see if other waveforms are affected.
Regards,
Dave
Somewhat unnerving that its labelled as 12v but measuring 15.8V and has 16V rated output caps. They should be 25V rated.
These voltages may well be an issue. Mine are around 14V. The negative 5V regulator gave up the ghost, truncating the negative half of the output waveforms. Both it and the positive 78L05 got stinking hot in operation - I couldn't touch them for more than a few millisec- and the 100uF capacitors got uncomfortably hot. Replaced the negative regulator, then the positive one carked. Its replacement carked, so I mounted a TO220 7805 and ran wires to the SMD pads. Both the regulators are now tolerable to touch. I took the opportunity to replace the metal can caps with 25V tantalum/MnO2 types. They barely get warm. It's been running a couple of hours now. Fingers crossed.
And on another subject - if you ground the signal common, run the 3rd pin ground to the power supply board, not the main board, otherwise when you disconnect the power supply board from the main board it is easy to defibrillate yourself. (Ask me how I know...)
Not sure I agree to that.
There are some issues with this device, but the 4ns jitter? I strongly suspect that the 10x more expensive equivalent Rigol DG1062Z 60Mhz 2 channel AWG has the same issue.
So we are getting a more then we paid for.
In fact, all of the device is a good deal, with all quirks, even the leaky PSU, if you check price/performance to what said equivalent Rigol would cost.
Only the firmware-self-destruct is below par. So far below par I cannot advise the device till they have a warranty system.
Sorry. I expressed myself wrong. I meant that for this money you cannot expect it to be perfect. And yes, this generator certainly satisfies my needs. By the way, I replaced the power supply again. Or, rather, the transformers to one torroidal. Voltages are still +-15V. Also, replaced the 16V electrolytics to be sure with 35V ones (not SMD but through-hole ones; just soldered them on top and used some hot glue to fix in place). Now, somehow, the waveforms do not show ANY visible distortion at any settings. Even the slight distortions you saw in my previous post, are gone.
Can you test this specifically with some frequencies which are whole divisions of the 250mHz clock. Like 50.00, 41.66, 35.71, 31.25, 27.77, 25.00 MHz
I did the measurements at the requested frequencies, a lot more carefully than the previous day's rough look, and took the average over four separate trials, after a 30 minute warm up period. The Ch1 trace was centered exactly on the crosshairs at 25MHz, and the Ch2 lag time was measured at each frequency, the results being:
25.00MHZ 1.00nS
27.77MHz 1.00nS
31.25MHZ 1.10nS
35.71MHz 1.00nS
41.66MHz 1.10nS
50.00MHz 1.20nS
In fact, the relative phase shift was constant from at least 5Mhz to 50MHZ, but both traces kick laterally by about 2nS at 20MHz - otherwise their positions are quite stable.
One thing I did notice today, however, is that the Ch2 amplitude is about 0.15v less than Ch1's when set to 5v at 25MHz, when the channels are supposed to be in sync, and the difference appears to get bigger as the frequency increases. I'll have to have another look at that to see exactly whats going on over the whole range, and see if other waveforms are affected.
Regards,
Dave
OK, I have a confession to make.
Just to dot the i's, I figured I also measure the delay on my device for all these frequencies.
*and now I measure the same 1.2ns*So I tried all sorts of things to recreate my original delay of 4ns. Long story short, I think I used cables of different length back then...
Sorry
However, the 4ns jitter (and its explanation of 250MHz DAC) stands. Just the phase difference does not, it is 1.2 and not 4 on my V3.1.
Yep, different length cables certainly make a difference - even 25mm, as I've just found out, is noticeable when the cables are swapped over.
I've also discovered that the 0.15v amplitude difference I was seeing was caused by the ultra-crappy BNC lead which Feeltech supplied: it's got twice the resistance of an RG58 lead of similar length, and probably a huge impedance difference as well. The BNC connectors are so loose they won't lock onto the sockets properly, and one of them even pulls straight off!
It's prompted me check all my interconnect leads, and I've discovered that I haven't got a single pair of equal length and made from the same cable and fittings, so that's my next little tasklet for this evening....
Damn Chinese piece of crap!!!
I was today using the fy6600 for some tasks and all of a sudden here what jumps out. The sine wave goes crazy. It is all over the place (multiple sine waves flashing all around) and the screen of the fy6600 starts showing all kinds of mess. The supply voltages are fine. Output amps seem to work fine, but there is something with the soft, I think. My version is 3.0. Damn Chinese crap. Does anyone have experience of FeelTech responding to these issues?
You're done for it, as you can see the<firmware version 3.0 it's a time bomb, and yours just exploded.
Interested in joining the firmare reversing/extracted effort, because there will not be any trip to China and back for your device ?
DC1MC
I found I could use mine by resetting the idiotic values. IIRC there is an ARB setting with a valid sine wave. As for the rest, read my .sig :-(
Sure I am interested.
What a nonsense those guys do not provide any support for soft upgrade!
Out of curiosity, Vytautas, why don't you give the "Help - Repair_Sine" option in the latest control software a try. We don't know what it does yet, but my guess it was added in after it became known that 3.0 was a major problem, and this could be the fix for it.
Out of curiosity, Vytautas, why don't you give the "Help - Repair_Sine" option in the latest control software a try. We don't know what it does yet, but my guess it was added in after it became known that 3.0 was a major problem, and this could be the fix for it.
No, this unfortunately is not the fix. Not sure, if this even is a fix for anything else...
The only thing on my V3.0 which remained not being totally scrambled is functionality of channel 2. Since the display still is not of much use though, the PC software helps a bit controling the thing.
And in fact, after applying the „fix sine“ from the menu, also the sine shows up again. But unfortunately, this does not last long, nor does it survive a restart. So you end up applying this again and again...
P.S.: just for completeness - nothing heard back from Feeltech, no proposal or anything.
Just tried the "sine repair" thing. Thank you for notifying me.
Unfortunately, that is not repairing anything. Now I can control the sine wave from the PC and it works, when controlled by PC. But the rotary knob does not work for setting the frequency, it only controls the amplitude. The screen still has various signs on it. And other waveforms do not work in any way, neither when controlled from PC.
In a current condition its a 100 euro paper weight.
I saw the topic on FY6600 and signed up,
Thanks for all the great tips and suggestions ,
I just ordered one from ebay,
I was thinking ,a neat way to get galvanic isolation without completely replacing the psu with a linear one is to simply add a shaver transformer isolator socket to the enclosure 230/110-230volt ,plenty of room to mount the switch modes along side too .
Costs around 10 euros from my local electrical supplier .
I think two seperate switchmodes is the way to go ,one for the 5 volts and another for the +/- rails .Replacing the no brand psu caps with proper items should help a lot also. Rf and magnetic sheilding of the transformer and switchers might be worth doing as well as some extra LC at the dc outputs .
Common shaver type socket
Theres a chunky ground terminal on the transformer ,that could remain permanently bonded to mains earth . A 'system' ground switch could be placed between the ground terminal of the psu and mains earth,that way you decide if you want the unit grounded through the mains line or via the unit under test etc ,it allows ground loops to be broken if the need arises .
I havent tried feeding a switchmode from a transformer before ,the windings will drastically limit the initial inrush current compared to direct mains connection ,probably no bad thing as the capacitor charge on regular wall warts etc creates quite a spark when they are plugged in ,something Ive never liked about switcher psu's .
Why would you order one after reading about the FW issue?
Before I purchased the unit I messaged the seller asking which firmware revision his units were ,I still havent heard back on it from him .
I went ahead and ordered but told them to hold the order until I get the answer to the question .
Before I purchased the unit I messaged the seller asking which firmware revision his units were ,I still havent heard back on it from him .
I went ahead and ordered but told them to hold the order until I get the answer to the question .
I purchased my unit on Dec 8th and received the 3.2 FW
Sent from my XT1575 using Tapatalk
Thanks for that Mr Fabe,
Hopefully the bad units have been cleared by now ,the supplier I ordered in from seems to have high volume sales so fingers crossed its all ok at this stage .
I found the op amps for the output stage on ebay too ,so I'll most likely solder a couple of them in while Im at it .
The interest and enthusiasm I found here made me want to buy one ,I can take care of the few fixes like mains isolation , extra power supply capacity and adding the output opamps for about 20 euros in parts so its worth a shot.
Touch wood my version 2.9 has been fine apart from the sort out issues earlier this thread. Unless you go over $500 you are still hard pressed to find much if any improvement in features and performance which makes the lack of decent assistance from Feeltech ridiculous as they have a niche they could control.
In the worst case you get a good FPGA development kit
.
The probes are set, the sniffing will commence soon !!!
Hi, DC1MC,
please, continue your good project.