Hi Johnny,
you are aware that the Siglent SDG2042 isn't in any way based on the design of the Feeltech device. It also isn't in a plastic case, based on the same design or even follow any of the same design decisions? It's a €600 device that you are comparing to an €80 toy? I would expect that any issues Siglent need to remedy will be approached at a whole different level than the guys at Feeltech would.
McBryce.
Damn right!
![Angry >:(](https://www.eevblog.com/forum/Smileys/default/angry.gif)
Oh, and BTW, thanks for giving me the opportunity to explain my (justifiably) jaundiced view of Siglent's AWG/function generator product line.
Quite frankly imo, Siglent should be hanging their collective heads in utter shame over the shambles of a UI that's been imposed on their whole AWG range. I can't believe that the DDS technology is any less capable than that used in the Feeltech models from the FY6600 series onwards in regard of the 1μHz resolution across a 14 digit range (DC through to 60 or the 100MHz maximum of the latest FY6900-100M).
It's a complete and utter mystery to me as to why they should have deemed a maximum of 11 digits via the keypad (with a mere 8 digits displayed maximum if using the rotary encoder) should be sufficient in a function generator that can be locked to an external atomic reference that can provide the required level of stability and accuracy to justify a 1μHz step size at least up to and around the 10MHz region of interest.
It's not as if the display lacks room for the additional six digits required to allow 1μHz steps up to the 100MHz region to be displayed if they abbreviate "Frequency" to the industry standard form, "Freq". If these AWG models had lacked an external reference socket, these limitations wouldn't have been an issue.
I can only guess that the external reference socket (unfortunately cursed with a b-directional function to allow it to export its internal +/-1ppm 10MHz clock by default to create mayhem on an existing linear bus section of a lab reference distribution system) had been a late addition in its development program wherein the additional 6 digits' worth of resolution had failed to make it into the original firmware design brief, leaving only the matter of this add-on feature as a last minute hack job to add an ill considered set of user options into the UI.
As you can see, this is the other major fail in these Siglent AWGs. If they'd invested a few more cents into adding a separate reference output socket to eliminate this bi-directional clash scenario, there would not have been any such risk of polluting a lab reference distribution with such a low grade 10MHz source.
I'm well aware of the benefit of synchronising to a single master clock even when it falls far short of the accuracy expected of a dedicated lab standard 10MHz reference but when you're cost cutting on sockets, you should at least put a little more thought into the management of your bi-directional reference socket's functionality than has been demonstrated here.
![Roll Eyes ::)](https://www.eevblog.com/forum/Smileys/default/rolleyes.gif)
I'm sure there are a few more shortcomings in the UI but these two are the most egregious imo considering it's now some
five six! years and counting. I'll leave the lesser shortcomings to be reported by others for the time being.
I've already had numerous email discussions just over 11 months ago with Thomas Rottach, head of Siglent's European sales division, involving an SDG1032X I'd just purchased from Telonic which had a faulty VCXO (it looked like a flicker noise ripple effect on its EFC pin) as a result of Telonic's own "technicians" and the supposed technicians they'd consulted with at Siglent EU failing to understand my very clear sequence of DSO screengrabs and video evidence of the problem. In the end, I gave up on getting a price adjusted exchange for an SDG2042X out of Telonic and insisted on a refund on the basis of it being unfit for purpose.
To be fair, Telonic had been as much a victim of this muddle as I had and obliged my request with alacrity, even to the extent of collecting the ailing SDG1032X at their own expense. I'd have preferred to upgrade my spending with them but the process had dragged on for several weeks by then, so I ordered the SDS2042X from Labtronics from whom I'd purchased my SDS1202X-E two years earlier.
Within a week of placing the order, I had a brand new SDG2042X in my hands. As per usual, I had picked the worst day of the week, possibly a bank holiday weekend, to place my order and expect a 3 day delivery schedule. Anyhow, the first thing I did was to repeat my "Frequency accuracy and stability tests" to verify that it was completely devoid of the 'jitter issue' I'd discovered in the SDG1032X following this up by confirming that this shared exactly the same UI defects I'd mentioned to Thomas Rottach (head of Siglent's European Sales Division) in no uncertain terms during my many email exchanges.
He had told me that he would pass on my UI related concerns to the Siglent factory technicians for consideration in the next firmware update. I've just checked for the latest firmware update but I see it's the same one that had been released almost two years ago which I'd downloaded back in November last year. So much for Mr. Rottach's assurances.
![Sad :(](https://www.eevblog.com/forum/Smileys/default/sad.gif)
There did happen to be an external/internal reference clock related fix in this last update but it related to disabling the automatic reversion to its internal clock reference on detection of the loss of the external reference, with an icon to signify this state and a pop up message whenever you try to turn a channel on.
This is far from the solution I'd hoped to see and strongly suggests that the hardware involved is incapable of using its internal reference without polluting the connection to the external reference network with a duplicate of its own clock. IOW, an issue that can't be properly fixed with a firmware update, hence the kludge solution used in this last (final?) update.
Fortunately, this is not the end of the world since the problem can be worked around by giving it a dedicated feed from a 10MHz distribution amp that can provide the necessary isolation between its ports. It's the strangely crippled frequency entry UI that's the most egregious shortcoming of these function generators and that's a fix that does look amenable to a firmware update.
Who knows! Perhaps one day soon, we may get to see the full frequency setting capabilities of Siglent's AWG range finally released from its prison of incompetent firmware coding to match the reach of that of the Feeltech FY6600 and its successors. Despite the lack of a numeric entry keypad (or possibly because of this lack) Feeltech's solution to providing the means to adjust the frequency in 1μHz steps all the way from DC to 60 or even 100 MHz looks like an act of genius compared to Siglent's rather lackadaisical effort.
Yes, as supplied, the last 8 digits were a complete waste of space until it had been upgraded to an OCXO clock reference with an external 10MHz clock reference socket. It seems to me that Feeltech had designed the FY6600 to the highest standard and then proceeded to apply their cost cutting compromises only to those components that could be readily upgraded by the keen cash starved hobbyist (Feeltech's target demographic) to polish this rough diamond into something of a gem that could ultimately outshine the SDG1042X and its contemporaries. A numeric keypad is a nice luxury but, at the end of the day in this class of test gear, that's all it is, a non-essential 'luxury'.
Don't get me wrong, I'd retire the FY6600 in a heartbeat as soon as Siglent fix their crippled frequency setting UI. Until that happy day arrives, the FY6600 will remain my 'go to' function generator and my SDG2042X can continue its usefulness as a plinth for the FY6600.