Description: Function generators are useful in a ton of applications from RF to embedded logic. They’re not usually super cheap though. Good news: we found a kit. The FG085 MiniDDS Function Generator is a ‘some assembly required’ kit that becomes a flexible, functional and easy to use frequency generator. Just solder the through-hole parts in place, attach the face/base plates and before you know it you’ll be generating sinewaves at frequencies up to 200KHz! But that’s only one of the tricks this thing can do. Three different operating modes allow the FG085 to generate 7 different types of continuous waveform as well as servo test and control signals in micro-second resolution.
The LCD screen and menu system make this an easy instrument to operate. Frequency, amplitude and offsets can all be set with the number pad and incrementally adjusted with the rotary encoder. The incremental step size can even be adjusted to make sweeps over a wide range easier to handle. The FG805 can generate a peak to peak amplitude up to 10V with an offset range from -5 to +5VDC. It can even be used as an adjustable DC voltage source by setting the amplitude to 0.
Based on 10 ratings:
3 of 3 found this helpful:
Nice kit, easy to assemble if instructions are carefully followed. It is well designed and easy to use.
Two problems though: (a) the BNC connector on the output cable is too tight and doesn’t fit the output plug (!) this was not an issue for me because other cables I had work well, but this may be a problem for others and (b) the output signal is extremely noisy and not really suitable for many analog applications.
1 of 1 found this helpful:
Simple to assemble, it works very well !!! Perhaps white noise can be added …
The kit went together easily in about 30-40 minutes.
The DDS firmware on the kit I received is a revision old. The latest is 113-08502-053 which fixes a bug with frequencies less than 40Hz (see the product page link below).
As Member #207448 already mentioned, the output is extremely noisy at line-level voltage and essentially useless for audio applications.
Frequency is pretty much bang on.
And lastly, be wary of the indicated amplitude. I took some sample measurements on my Rigol DS1074Z with a 10kHz square wave:
Indicated: 0.1V - Measured: 260mVpp
Indicated: 1.0V - Measured: 1.20Vpp
Indicated: 3.3V - Measured: 3.60Vpp
Indicated: 5.0V - Measured: 5.4Vpp
Overall, a good and fun kit but I was hoping to get better performance for audio amplitude and frequency ranges.
I needed a signal generator for a hobby robotics project but couldn’t justify shelling out hundreds for something I wouldn’t use very often. Found this little kit and decided to give it a try. It has exceeded all my expectations! The kit itself is very well designed and fun to build. Took about two hours on a Saturday morning to put together. Powered it up and it worked great! Hung a scope on it and played around with a lot of the settings, then put it to use tuning an op-amp circuit on my robot. Worked flawlessly. I haven’t begun to scratch the surface of its capabilities either. The only thing I added, that it didn’t come with, were some stick-on silicone feet to give it a nice grip on my work table (a few bucks at Home Depot). I’ve already recommended this unit to a friend who builds circuits for a living. He was equally impressed and ordered one for himself.
The kit was easy to assemble and worked perfectly right from startup. Frequencies and wave forms are clean and accurate. Like to see it work at several MHz. This is a good buy.
I bought this to help my oldest son with a science fair project. We needed to generate specific frequencies to be pumped into a rubens tube for sound wave measurement. As a bonus I was able to teach him a bit about oscilloscopes when I checked the accuracy of the generator (which by the way was dead on). All in all a very nice little product, well packaged, and fairly easy to assemble. Good project for a beginner that is wanting to try out a build and challenge themselves. One note, the ground leg for the output connector is a hair too short to reach the board, and the instructions say to cut it off and solder in a piece of wire as a replacement. I opted to keep the leg, and make a pair of J shaped hooks to drop in and act as a bridge to the board. I felt that it gave a much sturdier connection that wouldn’t break if there happened to be any pressure applied.
0 of 1 found this helpful:
This kit was fun to assemble but there were certain items that drove me to this rating. Step 10b says to cut wing off spring washer and solder metal lead and bend to shape. OK, no problem. But, although the parts list calls out the metal lead, it wasn’t included in my kit! No big deal, I made one. Next, after assembly was complete, I powered the unit up and, as mentioned in the first time power up instructions, the screen remained blank. Per instructions, I turned the unit over and attempted to adjust the trimmer pot. Nothing, in fact it broke! I now have a perpetual blank screen. Perhaps I’ll play around and try to change out the pot.
The function generator works (sort of), but there are a lot of things that should have been fixed before they started selling these.
I have a detailed review (with plots) at https://gasstationwithoutpumps.wordpress.com/2015/07/16/fg085-function-generator-bugs/
I was on vacation , and had a bout with a stiff neck wasn’t feeling very good ,all seems ok ,should start after the 4th of July as things will settle down , thanks for asking I’ll let you know n when I finished these two project for my invention . Al Cortes
Very pleased with it. I would like a cabinet or case for it. Would be nice if one was available. Even one made out of heavy cardboard would be very helpful. — I plan on making one with cardboard and some tape. Put in a chunk of metal for weight, and it will be much handier and usable, for me anyway.