Koolertron Upgraded 15MHz DDS Signal Generator Counter,High Precision Dual-Channel Arbitrary Waveform Function Generator Frequency Meter 200MSa/s (15MHz)

I tested pretty extensively, and it's impressively accurate. For the price, the company seems to make the best signal generators you can get by a mile. Controls are smooth and functional, display is fine, and comes with clips.A couple things to note:1. It's super light. The board inside looks to be the same board used with their portable model: https://amazon.com/Koolertron-Precision-Generator-Dual-channel-Frequency/dp/B07597TJPC/ Works great, but means that the thing slides around on a bench very easily. Hot gluing it down or securing some weight inside it fixes that.2. As usual, the rated frequency only applies to the sine wave. The biggest difference between this and a higher end piece of kit is that with this, the other (non-sine) forms degrade more / at lower frequencies. So you couldn't use the square wave, for example, as a harmonic generator for driving UHF resonators or the like. But if you want to do that, you'll have more specialized equipment anyway - something like WindFreak's stuff.3. The max amplitude of 20V only applies up to a frequency of (IIRC) 10MHz - after that it's 10Vpp. Most generators limit to 10V or maybe 15V from the start, so it's nice that this does 20 for much of the range.4. What really impressed me is that they have the frequencies and impedance as accurate as they do. They clearly tested and calibrated this thing thoroughly. Just a great piece of equipment at a killer price.

This is a great audio generator for the money. It's stable, has a clean output, tons of features and it's really easy to use. The screen is well lit, and it only takes a short time to learn the UI. I work on audio gear, and it's got everything that I need. The stability is good enough for my wow/flutter test, and the multifrequency waveform is perfect to troubleshoot filters. Everything works like it should. The only negative would be the thing is so light, you have to have a hand on top when you push a button or you'll push it off the shelf. Tie it down some way, or just learn to hold it while you use the buttons. I'm very happy with mine.

I’m impressed by the capabilities of this signal generator. Not long ago, a device like this would have been prohibitively expensive. The unit is compact and lightweight yet performs exceptionally well, making it a great addition to any test bench. While I’m very satisfied with its functionality, there are a few design elements that could be refined.The display and menus, although in English, retain some stylistic influences from the original Chinese design. This has no impact on usability but may feel slightly unconventional to some users. Setting the operating frequency is straightforward, though the process is a bit unconventional—you select a specific decimal position and adjust the value with the control knob.One minor inconvenience is that while the unit offers plenty of memory slots for saving operational states, it always starts up with its default settings rather than remembering the last frequency and mode used. It would be much more user-friendly if it resumed the previous operational state upon powering on.That said, these quirks are minor and don’t detract from the unit’s overall performance. While it’s not reference-grade test equipment—understandable at this price point—it is an extremely capable and excellent value for general-purpose use.

I am amazed constantly over how far electronics have come. This little generator is rock solid. It is accurate and within specs. It is so light that I had to attach rubber feet to the bottom to stop it from skittering around. It has a lot of memory slots available to store settings and arbritrary waveforms. Whatever you store in position zero is what it uses at boot. It is powered by a 5VDC wall wart so there is no internal power supply. I come from the day when devices that could only do half what this does and they weighed several pounds, had to warm up and even then drifted to no small degree. Let me cut this short and say that if you need a signal generator and don't want to pay for lab grade precision you may never need this thing is worth a try. It comes with decent cables, a booklet that is enough to get started, and a disk with the programs you need if you want to craft your own arbitrary waves or what not.

Edited review: regarding the duty, I realized that there was specifically a pulse wave which is affected, and that the square wave is not. This was confusing since duty is selectable for all waves, but it does work. I also took this into the lab today and compared it to lab quality generators. I’m creating very low voltage, low frequency signals on this thing (10 Hz at 0.1V) and attenuating it down to about 200uV. This thing is a beast and does that no problem, even slightly better than some of the lab grade equipment we have. Do your own tests, but for my purposes this exceeds my expectations. I still have not tried creating software defined arbitrary waves, but if that works reliably I’d give this 6 stars if it was possible.Original Review: I’m using this for very low frequency, low voltage stuff (10Hz @ 0.1V) and it does a pretty good and reliable job. So far the only thing that doesn’t work is the duty. Adjusting it still results in a fully symmetrical wave. I also haven’t tried uploading arbitrary waveforms yet, but watched a YouTube video that tracked down the required software and it seemed a bit annoying to set up. So far it’s been a productive instrument, but unfortunate that I didn’t get a feature I paid for.