Arb generator that is worth owning? - Page 1
Forum section: electronics / beginners

author: FriedMule
author_rank: Frequent Contributor
timestamp: September 14, 2019, 08:41:41 am
content: I have read, looked reviews, opinions and much more but to me does it look like everyone either gain to recommend there product or only have good opinions about what they own because thy do not know others. All except on this site where I have fund many different opinions on what is great for the tread starter. Unfortunately is it hard for me to understand or decide if there need is the same as mine. Hope you please will help to point me in the right direction. :-)I know that Siglent, Rigol, Owon, Agilent and other do make units but I can not fully understand and decide if the specifications are true or inventions, like a Siglen should be better then an Agilent, on the other hand is Agilent often 10 X the price.Here is what I think I need (or better):Cost:Prefered below 500$Waveform type max frequency: square, sawtooth, arb, sine 10MHzBits, 14 or 16: High PrecisionMax amplitude and current: 5V ?A2 equal channels: YesCombine channels: YesPhase control: yesOutput protection: ShortExternal clock input: yes 10MHzExternal trigger input: PreferredUSB pen reader

author: tautech
author_rank: Super Contributor
timestamp: September 14, 2019, 10:04:31 am
content: SDG1032X easily meets all your requirements.https://www.siglenteu.com/waveform-generators/sdg1000x-series-functionarbitrary-waveform-generators/However SDG2042X for 16 bit and touch display is right at the top of your budget.Check the datasheets as I think they both can supply 200mA.

author: GerryR
author_rank: Frequent Contributor
timestamp: September 14, 2019, 12:12:45 pm
content: BK Precision 4053B / 4054B line is really nice. I have a single output 4045B which I use often. I had an HP33120A, 15 MHz Arb, which was good and can be had used, for under $500.00, though I think the BK is easier to use.

author: bd139
author_rank: Super Contributor
timestamp: September 14, 2019, 12:18:30 pm
content: I like the Rigol DG1022Z. Cheap, two channels, excellent performance (better than most of the rivals) and you can crack it to 60MHz.

author: jpb
author_rank: Super Contributor
timestamp: September 14, 2019, 12:21:36 pm
content: I think almost all arbs (there are exceptions of course) have an internal resistance of 50 ohms so that they supply 20V to high-Z and 10V to 50 ohms so they can supply 200 mA at 10V into 50 ohms.Lowering the impedance will increase this a bit but at a lower voltage.Imax = 20V/(50 + R).Vmax = Imax.R = 20R/(50 + R) or (20 - Vmax)*R = 50*VmaxAt 5V out R can be 250/15 = 50/3 ohms and Imax = 300 mAThis is assuming that they can supply up to 400 mA into a short circuit - they may have a minimum load impedance.

author: FriedMule
author_rank: Frequent Contributor
timestamp: September 14, 2019, 12:29:54 pm
content: I take a look, I have seen on some generators but it looks like the sinus is what they mean when writing 16Mhz, while the other may only be 2Mhz. I would like them all to be at least 10MHz, even the abr generated signal. I would also like that the signal is as clean you can expect for my budget:-)Lastly would a touch interface like that on Siglent be great.

author: ledtester
author_rank: Super Contributor
timestamp: September 14, 2019, 12:30:05 pm
content: Have you seen this opinion:https://www.eevblog.com/forum/testgear/recommended-function-generator-for-hobbyist/msg2653164/#msg2653164I have an early FeelTech unit and I've spent more time modifying it than actually using it.So I definitely would agree that you shouldn't overbuy an AWG.

author: FriedMule
author_rank: Frequent Contributor
timestamp: September 14, 2019, 12:59:20 pm
content: LOL yes I have read that thread:-)m It's there I "stole" the idea about the requirement list:-)

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 14, 2019, 02:26:49 pm
content: At this point in your collection of equipment I think this is one area you could do on the cheap and be fine for some time. I recently bought a $30 AWG by Sain Smart.https://www.amazon.com/gp/product/B00JTR66CG/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1It will give you the basics until you really have an idea of what you need. Up from there maybe a deal on one of the older FeelTechs, I have heard some of the 6600 units going for $50 or so. You might be able to find one of the original versions of the Analog Discovery cheap/used that would give you a bunch of tools of limited power. I found one for $50 on eBay a while back, but it took some looking.

author: tautech
author_rank: Super Contributor
timestamp: September 14, 2019, 08:24:00 pm
content: Quote from: FriedMule on September 14, 2019, 12:29:54 pmYes that can be the trap and you must study datasheets to see which waveform types do what frequencies.In ARB mode some can produce frequencies way past their rated frequencies if you get the code right.QuoteIt's touch or front panel interface and if you have touch you will definitely use it for some adjustments as it speeds up usage.

author: rstofer
author_rank: Super Contributor
timestamp: September 14, 2019, 08:46:24 pm
content: I bought the SDG2082 because I could and there was a thread about generating a Valentine's Heart by combining a bunch of harmonics with phase shift. It's around here somewhere.It is typical that waveforms other than sine have a maximum frequency well below that stated for the sine. The Siglent SDG2000x series is limited to around 25 MHz (if I'm reading the specs correctly). It states 9 ns rise and fall times (10%-90%) so if we considered just the edges we would see about 50 MHz. But there really ought to be a flat spot on top of a square wave and that's probably why it is limited to 25 MHz.http://www.spinelectronics.eu/ftp/datasheets/SDG2000X_datasheet.pdfhttps://mediacdn.eu/mage/media/downloads/SDG2000X_UserManual.pdfSo, you probably aren't going to get the full frequency on other than sine waves.As I said, I bought it because I could and I wanted to play with the "Heart". I can generate very nice waveforms with my Analog Discovery 2 for a lot less money. A lot of people slide right on past the AD2 thinking of it as a toy. That's a mistake! They could do a LOT of electronics for $279 in equipment costs. Yup! It's on the lower end of frequency but more than adequate for just about anything a hobbyist could get into.https://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supplyAnd it has a 2 channel arbitrary waveform generator... Don't overlook the advantage of a 27" screen!

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 15, 2019, 04:06:31 am
content: And the AD1 is 98% as good as the AD2, and Digilent sold a ton of them to EE students for $99. They are out there sitting in drawers waiting to be found. At $279 for an AD2 against the price of a 1054z in the mid $300s it's a tough sell, but for under a hundreds bucks, a no brainier.

author: FriedMule
author_rank: Frequent Contributor
timestamp: September 15, 2019, 04:26:33 am
content: I thank you all a lot and will look at every product you write about. :-)

author: Mattjd
author_rank: Regular Contributor
timestamp: September 15, 2019, 01:38:22 pm
content: Quote from: bd139 on September 14, 2019, 12:18:30 pmI haven't seen this one, I have the dg1022z.

author: rstofer
author_rank: Super Contributor
timestamp: September 15, 2019, 03:49:08 pm
content: Quote from: Old Printer on September 15, 2019, 04:06:31 ameBay has a couple of AD 1s for sale at reasonable prices but mostly they are trying to sell the AD2s for half again more than they cost.But it isn't just a 2 channel scope, it includes two arbitrary waveform generators, two power supplies (limited), digital IO/pattern generator and so on. Priced against just a scope, the scope wins. Priced against a bench full of instruments, I'm not so sure. And the scope channels have differential input (until you use the BNC adapter) which can be fairly handy when you want to specifically measure the voltage drop across a component that is not tied to ground.It's probably true that the market for this gadget is students, not hobbyists. Add a breadboard and a handful of components then toss in a laptop and you have a lab in a backpack.

author: rstofer
author_rank: Super Contributor
timestamp: September 15, 2019, 04:05:05 pm
content: When looking at specs, find out how many harmonics you can add to each channel. Can the harmonics have individual phase shifts and adjustable amplitude?One of the cool things to do is generate a square(ish) waveform from odd harmonics of a sine wave at appropriate amplitudes. Each harmonic has a phase shift of zero and an amplitude of 1/harmonic number. The fundamental might as well be 1V so the 3rd harmonic is 1/3V and the 5th harmonic is 1/5V and so on.https://en.wikipedia.org/wiki/Square_wave#Fourier_analysisAs you watch this Fourier series begin to approximate a square wave (probably out around the 9th harmonic) you will suddenly realize why a 100 MHz scope can only approximate a square wave of 10 MHz (9th harmonic inside bandwidth of scope) or maybe 14 MHz if the 7th harmonic is all that is required. Even then, the frequency response of the scope is falling off.A good waveform generator can provide a lot of education. That's the difference between a real waveform generator and some of the low dollar kits. At best they are a signal generator, not a waveform generator. Not that they don't work, I have one. But I'm not likely to use it again unless portability is important. Then I would probably use my AD2.

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 15, 2019, 08:07:06 pm
content: Quote from: rstofer on September 15, 2019, 04:05:05 pmAgreed, I picked up the Sainsmart when I was traveling but did not have a laptop available to run my Analog Discovery. Capability wise there is no comparison, the AD 1 or 2 can do most any thing you can think of. I always try to point out how close the AD1 and AD2 are, except for the sexy green case. At $100 or less a working AD1 is really a steal to a beginning hobbyist or student.

author: TK
author_rank: Super Contributor
timestamp: September 15, 2019, 08:17:57 pm
content: Quote from: tautech on September 14, 2019, 10:04:31 amthe SDG1032X can be hacked to the 60MHz model

author: tautech
author_rank: Super Contributor
timestamp: September 15, 2019, 09:29:19 pm
content: Quote from: TK on September 15, 2019, 08:17:57 pmYep and SDG2042X to the 120 MHz model.

author: rstofer
author_rank: Super Contributor
timestamp: September 15, 2019, 09:50:24 pm
content: Quote from: tautech on September 15, 2019, 09:29:19 pmAnd the SDG2082? Not that I plan on doing it...

author: tautech
author_rank: Super Contributor
timestamp: September 15, 2019, 09:56:24 pm
content: Quote from: rstofer on September 15, 2019, 09:50:24 pmYep that too, hunt through the SDG2042X thread or the Siglent .ads thread for clues on how it's done.