A cheap MAX038 function generator kit (Pt. 2)

[@KeritechElectronics]

5MHz is already more than my sine wave generator that goes to 1MHz and can't output any other waveform, and is bulky (talk about 2U rack enclosure), but will be a part of my testing setup as I have fond memories of my high school and physics teacher tied with it, and I'm pretty sentimental even when it comes to electronic engineering :)

[@jlucasound]

OK. Maybe I will stay away from this one. Thanks, Roger! I personally like videos like this, where you analyse the Chinese DIY kits or even devices that are already assembled. Motor controllers, voltage regulators, etc.. There are so many! I think people will flock to your channel if you did more of these. IMHO. I wish you the best, Roger. From the USA! :-)

[@uwepolifka4583]

Nice. Will it give a "Fixing the issues with the XR2206" version for the MAX038?

[@KainkaLabs]

No. The problem here is in the non-RF adequate PCB-layout that can´t be fixed in any way with the orighinal PCB. An improvement could be to change the decoupling caps to better/larger ones so that the power-supply lines are cleaner and the jitter perhaps be reduced? And perhaps hand-solderung a BNC-connector directly to (or as a replacement of) the screw-terminals.

[@dalenassar9152]

I bet that using a better power supply and simply paralleling the existing decoupling caps with a different value and/or type would GREATLY improve the output! THANKS FOR THE VIDEO!

[@KainkaLabs]

What do you mean with a "better" power supply?

[@dalenassar9152]

I just gave a somewhat detailed reply, but do not see it in the comments...did you get it??@@KainkaLabs

[@KainkaLabs]

No

[@scottmorgan5370]

Do you have a schematic such as in the owner's manual for the ELV 9001m Function Generator that you tell us you have? I searched the Internet to no avail. Love your videos by the way... Many thanks for the work you put into them.

[@KainkaLabs]

You can download it from the ELV homepage for a small fee. It is called MFG900 and the article with the schematics is a three part series: de.elv.com/search?sSearch=mfg+9000&ffFilter[attributes-elv-ExtendedSearch]=Journal You have to create an account with a (guessed) German adress before or during checkout. You can pay with PayPal (or credit card) and then get a download link for the PDF. You have to put all 3 parts of the article series into the shopping-cart if you want them all 3.

[@scottmorgan5370]

@@KainkaLabs Thank you so much for the information and the ultra-fast reply.

[@scottmorgan5370]

@@KainkaLabs Can you tell us how the PCB could be improved in order to cut down on the noise in the signal? I'm a novice at this and I don't know how to go about laying out a board for optimum signal. I do know some better filtering on the power supply would be a benefit.

[@KainkaLabs]

PCB-layout suitable for RF-frequencies is not a beginner´s topic :-) You should use one side of the PCB (usually the lower side) as an (uninterrupted) ground plane. Then keep all the traces with the RF-signals (the output of the IC and the sync-signal) as short as possible and lay then out as so-called "strip-lines". Any components connected to the analog inputs of the IC should be placed as near as possible to the IC.

[@scottmorgan5370]

@@KainkaLabs Thank you very much for your expertise and your lightning fast reply. Any learning I get from you folks is greatly appreciated.

[@hvacmastermind7996]

Roger, I work only with audio signals. What's your opinion of this kit in the 1Hz - 20KHz range?

[@KainkaLabs]

OK, but too expensive. Get the XR2206-Kit.

[@szekerespista3758]

Can you recomend a good sawtooth generator kit or chip for 15 Mhz?

[@KainkaLabs]

15 MHz? Invest some money and get a real device from SIGLENTor RIGOL.

[@EngineeringAllAround]

9:05 and up. Your trigger position is too far before the displayed waveform. You should set it to zero to show the waveform. Measuring jitter is a separate topic.

[@KainkaLabs]

Trigger-point is very near zero volts. I don´t understand your comment. Of course I have tried it also with a higher trigger point. Same result. The jitter comes certainly by injection of extrenal noise to the frequency-setting input (or the frequency setting capacitor).

[@EngineeringAllAround]

​@@KainkaLabs trigger time (!! not voltage) is far to the left of the screen. You capture a moment that is while after the trigger event.

[@EngineeringAllAround]

That's why you see horizontal signal instability.