Low Cost Arbitrary Generator - Koolertron 60 MHz vs Siglent SDG810 

Very Informative. When you viewed the spectrum waveforms, I was thinking the same as you about the noise until you test the THD. I might have to review that section again. Thanks for the video.

Hi Eddie, Very interesting and helpful video, also the tutoring was great. Thank you so much 😊

Another great video presentation.. Thank you..

An excellent review and comparison, thanks Eddie! Wow, i thought that the way more expensive Siglent would kick the Koolertron's butt! I have the pretty-identical JDS6800 60Mhz and have been extremely happy and impressed with it.....but i always thought that it was kinda something to be ashamed of compared to the bigger/better names that i could not afford. Now i don't feel so bad. Thanks for that, and the review!

9:26 This Koolertron JDS2800-60M is in fact a rebranded version of the JDS6600 (Joy-IT) version in a slim design housing. The software is exact the same on both models. I have bought the JDS6600 a month ago, and i'm very happy with the features that this generator provides. 13:53 The sync function is between ch1 and ch2, you can choose what features you wanna sync, Freq, Offset, Amplitude, you can set each feature on or off. If you then return to the mainscreen and you set the frequency to lets say 20Mhz, then this 20Mhz is available on both channels. Between both channels there is a very very minor (few Hz) unbalance in the higher frequency range, but in the amplitude there is a difference of 0,2a0,4V between both channels. First i though it was a difference caused by 1 of the 2 coax cables between generator and scope, but swapping the cables between both channels on the generator or scope gives the same result. The only minor point that i experienced, and i think that also exist on the Koolertron, is that the powersupply leaks a voltage (86V in my case) to the negative part of the BNC connectors. When connecting the generator to a grounded scope, this leakage is gone, but it can give problems when using the signalgenerator on a floating sensitive circuit. 21:17 The 3 drops in amplitude from 20V to 10V and then 5V are because these signal generators use a step-up converter, to convert the 5V DC input to 10V and 20V, and at 20V once it reach the 10Mhz, the current begins to collapse, then i steps down to 10V to start a new range untill the current starts to collaps, and finally at 30Mhz it steps down to 5V. The maximum output current is arround 200mA, and the impedance of the signalgenerator is 50Ohm. And as a tip, to save settings on startup, just press the OK button till it beeps, if you then power down the signal generator, and even disconnect the powersupply, it still keeps it settings saved.

I see the Koolertron now comes in a nice desktop case, like the Siglent. Looks nice!

sinc is the name coined for sin(x)/x and is related to filtering, sampling and Fourier analysis, for which it is the pair of the square wave. A sinc filter has a rectangular frequency response.

nice :) i think this koolertron is more than enough for amateurs like me and many others

I bought a FeelElec FY6200 signal generator from Banggood. Think that was even under 100USD. Looks verry similar to that Koolertron generator. Even came with the same cheapish cabels. Interesting stuff.

very good

Thanks for this. I'm always looking for various arb generators

I have a question that may not be your area of expertise, but I’ll ask anyway. I’ve heard different types of frequencies may help people with different things. For example 174 Hz is said to help with pain relief. I saw a video in which each frequency can be manipulated into different sound waves ie: square, rectangular, etc . With that said, if I wanted to create and record a frequency for my personal use, how would I know what type of sound wave I would need to put the frequency in?

Great video. I'm guessing that your 'Koolertron' is internally the same as the FY6600, FY6800 and FY6900 models that have been available at speeds of up to 60MHz at about the $100 price point (with shipping) that have been around for several years. As you point out in the video, one of the biggest problems is that you have to be very careful about what the output voltage is because it will change with frequency.

Is the output impedance 52 ohms or 75 ohms or what exactly?

Can you produce a AM, FM Sweep and/or modulated .. let’s say for radio IF alignments?

You should do a comparison of the function generator that are built into the budget oscilloscopes you've reviewed.

I probably missed it but what was your scopes input impedance set at, 1M or 50 ohms ? Most gens are rated going into 50 ohm load. Last year I purchased 60MHz version which claim output impedance of 50 ohm but haven't had time to measure what it actually. When I get some time I will measure it. TNX 4 the upload

Is there a modulation function, say, for testing tube radio IF functions?

Interesting video very informative. Generator is good value but looks really cheap.

Can you check something on your koolertron the channel 1 button doesn’t seem to illuminate any where near what the channel 2 button does on my unit. If I turn channel 2 off and only have channel 1 enabled it still looks like the channel 2 button illumination overwhelms channel 1. Is this only on my unit or on all units?

Eddie, I have noticed that function generators will often quote a frequency for sine waves that increases as you go through the range (and cost). That doesn’t always translate into being able to generate a square wave at the same high frequencies. I do have a Siglent that is two channels and a higher headline sine wave max frequency. Interestingly the square wave also goes up to the same frequency. I have noticed a degradation of a square wave e.g. at 30MHz. To get a good square wave requires careful setup e.g. your 50 ohm BNC cable should be driving a 50 ohm terminator on the scope. At which point I get excellent results. In your tests, the ability of the FG to drive a load should be of interest to subscribers and even the cable used should be carefully selected. Shame on Siglent, you won’t get any cables. I had issues with a square wave until I realised my 50 ohm cable was actually 75 ohm. The clue was the marking RG-59 on the cable. It is enough, combined with a load, to greatly affect the output. In effect the cables can just behave as a filter network and so you are measuring the characteristics of a filter and not the FG? One of the uses for a FG is to introduce noise e.g. into an amplifier. The Walmart powered units can do this since their output is floating that can be missing from better ones. The number of waveforms, does it matter for real world use?

Seems to be quite a lot of features and acceptable performance for not too much money.Would probably have seen much more capability of the Siglent had you gone into the arbitrary waveforms and been able to compare the 16K length to the Koolertron's 2K...or not.

At 44:54 the sinc function is *not* a sync signal. It's not used to synchronise anything. Sinc is the Fourier transform of a rectangular function. See en.wikipedia.org/wiki/Sinc_function

I have a FeelTech FY6900 60MHz DDS. This Koolertron GH-CJDS38-B is same as FeelTech FY6600. All other brands have remarked FeelTech models as Koolertron, JDS, DOMINTY and others but internal are same as FeelTech SG-s and all of them have same mistake, SMPS. Because of that big mistake, instead of that BS SMPS I replace them and modify PSU with complete new DIY linear PSU. After all it work flawles. Wery nice piece of equipment for that price, unbeatable.

I'm still on the $10 diy kit signal generator.

SINC is sin(X) / X. Did they spell it sync?

A shame you don't make a disclosure in the beginning. I'm pretty unsure if it's a unit you have purchased for your own coins which I reckon it is.? since you don't mention anything else. Maybe it's my danish nature that just prefers it transparent when people sitting and promoting and recommending a given product and also with a bunch of affiliate links. all that is fine IMO - but it goes without saying that it will make things more transparent if you inform to the viewer' if you purchase it or you were gifted it, as a lubricating "payment" to make some promotion for it' - I also recall some YT policy about this aspect, and it goes without saying that the level of shill channels on YT that is promoting China-freebies left and right and where the sole incentive is affiliate-income and putting their a'ss up in the air in the hope China will hand them even more freebies in the future' is literally unreal these years.(all that is fine and up to the person own integrity, I just prefer things transparent when its product recommendation suited with affiliate links, and at least inform the circumstances). If you state it somewhere in this 55-minute video, my bad as it ain't in the first half and no critics of you, but more in general, as a shareholder of Alphabet (YT) I'm more or less fed up with YT-shill-channels with a sole motive on getting freebies & affiliate humping and were any sense of integrity is out with the bathwater. A disclosure goes a long way on products with affiliate links, and if the channel holder actually purchased this product themself because it looked solid / good value' - or its solely down to some China vendor that contacted them and it was that China-vendor that then decided what they wanted to promote to the viewer. Anyway, I also went for one of these cheap DDS arb-generator ½ years back. It was mostly just to have a signal-tool to get familiar with my new scope It was also a 60mhz. at around 70USD from an EU warehouse from this Goodbang in China. It was from the brand Feeltech or FeelElec model 6900 60mhz rev. 2.02 (60mhz 64 manual custom arb waveform, 8192 points 14bits sweep, mod, counter, VCO etc). the spec on that fellow en.feelelec.com/index.php?case=archive&act=show&aid=65 and same also Sine 60mhz while SQ is 25mhz and the rest is 10mhz. Here some internal pictures at the midpart in this slide - imgur.com/a/wo4v4Mz but still trying to find head and toe while plugged into the scope and find some common ground.. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Iy2NvuZUYXk.html But do like the computer interface, makes adjustment and input way easier and it runs fine on a plain 5v USB line to PC with the native dateline, though if I start to take advantage of the DC power features I reckon I need the AC but so far it works great just with the data line to the PC and no extra power.

Watch video @ 2x! You'll thank me later!