RD JDS6600 25MHz 2-Channel DDS AW Function Signal Generator

[Apofview]

Hi,
any experience with JDS6600 modulation.
In user manual there are modulation options sweep, pulse and burst.
I'm not able to find AM or FM modulation.
Other generator FY6800 seams to have AM modulation.
Does JDS6600 has AM modulation?

[Apofview]

Sorry, just read all the messages in topic.
JDS is a miss, I should bought FY, difference in price is around 5USD on aliexpress.
There is no FM and AM modulation.
Didn't consult forum prior buy...

[KeepItSimpleStupid]

How that pesky 60 V show up.

Attached is a datasheet for an EMI filter.  f you don't earth the junction between C1 and C2 you end up with about 1/2 the line voltage at this point.
The filter leakage current is 0.25 mA.     If the capacitors are the same, they will likely have the same shunt impedance.

Release notes

The designer of the instrument is missing the "Release note" concept.  https://www.appcues.com/blog/release-notes-examples
Here https://www.appcues.com/blog/release-notes-examples are the release notes for Firefox

i think they add a layer of trust between the user and manufacturer.

I never saw any for Keithley products, but they had to exist.  They verified a really nasty hardware bug where an Electrometer would put 200 V spike at the input.   They did not believe me at first.  They responded with an immediate external fix that crippled the instrument in other ways and later a fix for the instrument.

With another company that we had a good relationship with, I called them up and asked why do you have a 10 Amp rectifier where a 50A rectifier should be?
That actually required a new upgraded transformer and rectifier for free.

The exchange of information can be very beneficial.  That was not the case with Apple.  They did not want to check or I could not get past the gatekeeper near when my warranty would be up to investigate:
If I send an email with ATH$ in it on a dial-up line, the modem will hang-up every time.

Six months later they issued a firmware fix for the modem.
I've never bought an Apple product since. They would not do the simple test.

[Ghanou]

Btw, what's with the NOISE function of this device?
I connected it to an audio amp, and what comes out is nothing like white noise, it's some sort of buzzing sound, and you can actually set its frequency.
What is that good for? (maybe I am wrong to expect white noise here, but that pitched sound is not something I'd have in mind when someone says "noise")

EDIT:
I see, it's not an FPGA function or anything but also just a fixed table for DDS, and if I set it to 1 Hz, it does resemble noise with not very much high end. I guess it would be somewhat more useful if it had a lot more points in each table than those meager 2K.

it's an effect of the DAC (zero order hold) , white noise has a constant spectral density just like the delta impulse function, so what you're seeing is essentially the impulse response of the DAC at a given sampling frequency, you can see in this teardown video at 9:00 the usual frequency response of a sample and hold DAC:
https://youtu.be/b66nnWb3z54?t=521

EDIT: i bet its added just for marketing shit because its hardly any useful, you want your white noise to have a constant spectral density atleast to some higher frequencies so you can use it to view some filter's bode plot or some other system's frquency response.

[Mariocar]

Would anyone know where I can find the JDS6600 wiring diagram? Thanks for the help.

[Mariocar]

Hi. I'd like to know if you were able to solve your issue. I have the same equipment and I'm having the exact same problem. Although the equipment is working perfectly while connected to the PC via the USB entry and using the JDS software, the display still has the same defect. Thank you for the information! Kind regards.

[defcronyke]

Hey folks. I bought the "Koolertron Upgraded 60MHz DDS Signal Generator Counter, High Precision Dual-channel Arbitrary Waveform Function Generator Frequency Meter 200MSa/s (60MHz) Model: GH-CJDS66-FU" awhile ago on Amazon, which I'm pretty sure is the 60 MHz version of this same device being discussed, although if it isn't the same one I apologize, and feel free to remove my comment.

Anyway, I wanted to control this device from the command line (on Linux specifically), and after reverse-engineering how to upload user-defined arbitrary waveforms, I emailed Koolertron and received an official English-language spec for the usb-serial communication protocol from Koolertron's customer support, and while I don't think they'll let me share the spec document, they did authorize me to use it to make an unofficial open source program based on the spec. It looks like it's the official English-language version of the same Chinese document someone translated on this thread.

So anyway, I made a cross-platform command line program (tested and working on Linux and Windows, might also work on Mac but untested) which implements nearly the entire spec (minus some small things from the spec which didn't work as advertised or didn't make much sense), and if you're interested in using it, or studying the code to infer the official spec for your own uses (as it was provided to me in the real English-language document), you can find the project here, I just released the first version this evening: https://gitlab.com/defcronyke/signal-gen-cjds66

I don't claim that it's perfect or anything, there's likely a few bugs in this first version, but it can be considered pretty much feature-complete, and maybe you'll appreciate it. Let me know if you have any questions or opinions on it, and if you'd like to propose any changes to the program, you can do so through the gitlab project site (or I guess you can mention things in this thread, but I'd rather not hijack the thread). I made it for myself, but then I thought maybe other folks might find it useful, so if anyone else can get some use out of it then I'm happy.

----------

UPDATE 2021-01-07 - Linux and Windows x86_64 binary builds are now available with each new release from now on, so you don't have to compile from source yourself (now at v0.1.6):
https://gitlab.com/defcronyke/signal-gen-cjds66/-/releases

[sergio.fink]

Hellow people. I bought the JDS6600 and I have a problem with its CH2. I configured the CH1 and CH2 with a 50Hz sinoidal wave. I pluged in both channel 2 oscilloscope probes. In CH1 in the oscilloscope appears the correct waveform but in CH2 appears only a 5V DC level. Anyobe can help me about it?

[Zenith]

Put it on a bench. They don't work well glued to the ceiling. 


Is it new or used?

Have you changed the channels around? Do you have one of the channels of the scope set to ground?

You have probes connected to the scope and cables from the sig gen. The connection between the two is out of sight. Is it sound? Have you tried using just the cables or just the probes? Does CH2 of the sig gen produce anything apart from DC when it's set to any waveform or when it's the only channel active on the sig gen.

Try the simple things first and work through it. I suspect there's nothing wrong with the sig gen or the scope and this is something basic.

[MarkMLl]

I am assuming this means that a function generator with SYNC/TTL output generates a pulse at the very beginning (0 degrees) of a waveform, which in turn could be used to trigger the sweep on the scope.

Does the JDS6600 have such a feature? I see a reference to the "TTL extension interface" in the manual, with signals TTL1 and TTL2, but no explanation of their function or usage. Are these signals equivalent to a "SYNC" output?

Belated comment: https://www.controller-designs.de/index.php?lang=de&cat=projekte&cont=jds6600_sweeper&sub= (in German, but easily translated by Google) describes an add-on box which in some unspecified way sweeps the JDS6600 and also emits a sync pulse. It uses the TTL port for control, and I suspect that what it's doing is sending a rapid stream of commands to shift the frequency by some increment.

As far as I can tell, the signals on the TTL port are primarily to allow the JDS6600 PCB to be integrated into other testgear etc. so I expect the Rx and Tx signals to have the same level of control as the USB port (this is something I've spent substantial time on over the last few days). As such, it /might/ be possible to do a "barely adequate" sweep on one of the outputs, and to put a sync pulse on the other either by using the burst facility or by manually ackling it (DC voltage with changing offset).

Whether the amount of work required to do this, when compared with the price of a more capable instrument, can be justified... is moot.

MarkMLl

[Mariocar]

Hi, everyone. Could anyone help me, please? One of the channels in my function generator JDIS6600 has stopped working. I've checked it and verified that the integrated circuit (circled in the attached photo) is causing the issue. Since its identification number has been scratched off, I can't find out its code. Could anyone help me to find out the code so that I can replace it, please? Thank you.

[BillyO]

Mine is a 60MHz version and the board is a little different, but in that location there is a chip where the 3rd pin is being fed by a similar tiny 6 pin chip like in yours and it is an AD8056 low noise op-amp.

On yours you can see the tops of those characters, so it's pretty much what it is.

Good luck!

BTW, you can also see that in post 10 of this thread.

[Mariocar]

Thank you.

[lushprojects]

Very quick and dirty project to add a web interface to at least a few functions of the JDS6600:
https://github.com/sharpie7/jds6600web

[RobbiOne]

JDS6600 60MHz ... the main board rev. 18 seems different from the previous ones. For only 52€ on Amazon it was a real bargain indeed.  😁

[Oleksii]

rev 18. not scratched ICs under 2 heat sinks are LM71

[sergio.fink]

Hello people.

Please, anyone can identify what chip is inside in the red circle?

I have JDS6600 rev 15 and my channel 2 is not working with wave form signal. The channel 1 is working very well. I believe that this chip is responsable to supply the wave form to output channel.
Best Regards

[BillyO]

Please, anyone can identify what chip is inside in the red circle?

You should be able to read the numbers right off that chip.  However, if memory serves me it's an AD817 precision amplifier.