Help me choose the best bang/buck Function Generator - Page 1
Forum section: electronics / testgear

author: bsas
author_rank: Regular Contributor
timestamp: February 16, 2018, 06:49:10 pm
content: Hi all,I am putting together my own home lab to learn electronics and I am already with those items:1) I am between the Rigol DS1054Z (hacked) or the Siglent SDS1104X-E as my scope (still undecided);2) 2x EEVBlog BM235 multimeters (already bought to help David);3) 1x EEVBlog uCurrent GOLD (already bought to help David);4) 1x Tekpower TP1803D Lab Grade Variable Linear DC Power Supply 0-18V @0-3A (I have this for a while and works fine).So, now I am missing a nice Function Generator.I was wondering if there is any obvious "winner" that is an amazing bang for buck like the DS1054Z is for scopes. If not, any recommendation? I have nothing against trying to find old hardware on eBay too...Thanks!

author: ataradov
author_rank: Super Contributor
timestamp: February 16, 2018, 07:07:02 pm
content: Siglent SDG1025 (and other frequency versions depending on your needs) is a pretty good deal overall.

author: tautech
author_rank: Super Contributor
timestamp: February 16, 2018, 08:27:41 pm
content: Quote from: ataradov on February 16, 2018, 07:07:02 pm$319 vs $359 for SDG1032X.....I'll have 1032X any day !Selling my old demo SDG1010 (already spoken for) as it's nowhere as nice to use.X models also have identical output specs for both channels unlike older SDG1k models.Edit to add:If #1 choice favors SDS1104X-E then for Bode plot usage a Siglent AWG will serve as a sweep source rather than needing to purchase the optional USB SAG1021 AWG for $159 PLUS $109 for SW licence to use as a basic single channel AWG.

author: nctnico
author_rank: Super Contributor
timestamp: February 16, 2018, 08:40:00 pm
content: The Feeltech FY3200 series is nice (but needs a modification to add a grounded inlet and connect the ground to the BNC outer shells; this is not a safety issue but to direct the leakage current from the PSU filter to ground).

author: rsjsouza
author_rank: Super Contributor
timestamp: February 16, 2018, 08:43:35 pm
content: If you are looking for used hardware, I would look for a synthesized function generator such as the HP3314 - I have one that was bought at quite a reasonable price (around $100) and it works very well.

author: blackdog
author_rank: Frequent Contributor
timestamp: February 16, 2018, 08:48:57 pm
content: Hi,I have 3 modern signal generators HAMEG HMF2525, Rigol DS1104 and a Siglent SDG2042X.I realy like de Siglent SDG2042X, its 16 bits( low audio band distortion ) and below 1MHz the squarewave output is just perfect, textbook quality!Dual output and you can "upgrade" itKind regards,Blackdog

author: tautech
author_rank: Super Contributor
timestamp: February 16, 2018, 08:57:13 pm
content: Quote from: blackdog on February 16, 2018, 08:48:57 pmYes, they've been quite popular for the ability toimprovethem to 120 MHz.Good thread about it here.Whispers are that 1032X can be improved to 60 MHz. Shhhh, don't tell anyone !

author: rstofer
author_rank: Super Contributor
timestamp: February 17, 2018, 04:28:07 pm
content: I bought the Siglent SDG2082X and it is a fantastic AWG. It's on the pricey side but it has amazing capabilities in terms of adding harmonics to sine waves at arbitrary amplitudes and phase relationships.Read the datasheet on any device you consider. The SDG2082X is an 80 MHz signal generator but only for sine waves. Square waves are limited to 25 MHz and arbitrary waveforms are limited to 20 MHz. This is not an unusual situation.http://www.saelig.com/supplier/siglent/SDG2000X_DataSheet_DS0202X-E01D.pdfOn the other end of the scale is the FG085 which costs about $50. It's a pretty interesting device and it has a lot of functionality but sine waves are limited to 200 kHz. Don't confuse it with a real AWG because the waveforms aren't nearly as clean but it works pretty well. It comes as a kit with 'some assembly required'.https://www.sparkfun.com/products/11394There are more capable generators and there are cheaper generators but these are the two I use, along with the Analog Discovery 2.And I also have an RF signal generator but I don't use it a lot.http://www.newark.com/tenma/72-585/rf-signal-generator-frequency/dp/66F3578

author: nctnico
author_rank: Super Contributor
timestamp: February 17, 2018, 05:15:44 pm
content: What might be worth considering is to get a function generator with floating outputs. This can help to prevent ground loops which mess up low noise measurements.

author: rf-loop
author_rank: Super Contributor
timestamp: February 17, 2018, 06:23:07 pm
content: Quote from: tautech on February 16, 2018, 08:57:13 pmAnd, 60MHz sine out (independent of front panel model) have also 60MHz square wave! (rise and fall times around 4ns not adjustable but of course independent of frequency)Also other things can improve. Pulse rise and fall time. Triangle maximum and some other limits can "improve".My 1000X havetriangle max 5MHz (norm 500kHz )Pulse max 15MHz (norm 12.5 )pulse min risetime 11.8ns (norm 16.8 ) (Rise/fall times are user adjustable with .1ns resolution and rise/fall times are independent of freq, even in extremely low freq. Also width is adjustable and independent of frequency even if period is over 1 day (10µHz)Arb 1 cycle max 10MHz (norm 6MHz)AM modulation (internal) max 50kHz (norm 20kHz )FM modulation (internal) max 50kHz (norm 20kHz )PM modulation (internal) max 50kHz (norm 20kHz )Sweep time max 3600s (normal 500s ) This was starting point for mod because at this time this was my urgent need.I have not tested what are real max min limits for all internal "factory" parameters and other things what possible can "improve" but these I made quickly for my momentary needs.With Arb this Gen do not shine... it is same kind of fixed sampling, fixed length (16k) what is in SDG1000 models.But if this is ok, then this generator is small miracle in its price class. Not any kind of car garage made "soap box" el cheapo toys.)And of course this is directly (out from box - connect cables and power - do not touch) compatible with SDS1004X-E "BodePlot" function aka Sweep Frequency Response Analyzer (SFRA) what is far over Keysight 1000X bode plot.

author: BillB
author_rank: Unknown
timestamp: February 17, 2018, 11:15:48 pm
content: I've got a 1032 headed my way, and I would certainly recommend it. I would recommend it even more if it could generate at 60MHz... But, I'm having trouble locating these whispers?

author: tautech
author_rank: Super Contributor
timestamp: February 17, 2018, 11:49:45 pm
content: Quote from: BillB on February 17, 2018, 11:15:48 pmI think here:https://www.eevblog.com/forum/testgear/siglent-sdg1000x-waveform-generators/I have not tried it.

author: Muxr
author_rank: Super Contributor
timestamp: February 17, 2018, 11:58:19 pm
content: Quote from: ataradov on February 16, 2018, 07:07:02 pmI really like my SDG1025. It's a well designed affordable func. generator. I also have those cheapo FeelTech ones but the Sgilent one is in a different league. As someone mentioned Siglent has newer models now, so I would check those.

author: nctnico
author_rank: Super Contributor
timestamp: February 18, 2018, 12:09:37 am
content: Quote from: Muxr on February 17, 2018, 11:58:19 pmOne thing to look out for is that the original Siglent SDG1000 series' second output has a very limited output amplitude (6Vpp) which has bitten me several times already.

author: tautech
author_rank: Super Contributor
timestamp: February 18, 2018, 12:14:39 am
content: Quote from: nctnico on February 18, 2018, 12:09:37 amWhich was very common in AWG's of yesteryear !Nothing at all new about sig gens second channel having reduced amplitude.

author: rf-loop
author_rank: Super Contributor
timestamp: February 18, 2018, 12:06:19 pm
content: Quote from: Muxr on February 17, 2018, 11:58:19 pmSDG1000 models are robust and mature. Nothing like where ever car garage manufactured "soap box".But it is also bit old design and it can see in some details if compare Siglent's more new SDG'sIf do not go to SDG2000X models (what is very good in its price class)If look SDS1000 and SDS1000X models. SDS1000X beats SDG1000 in every single corner. All is better or far better.Most important things are.SDS1000X have equal end amplifier in both channels. (SDG1000 have reduced power in Ch2)SDG1000X have Siglent EasyPulse technology what means adjustable rise and fall times and pulse width and independent of frequency and less time jitter. As also in SDG2000X but not in SDG1000.Try to make 50ns pulse with 1 day period orone minute period with some other generator and then adjust rise time from 18ns to 25ns using 0.1ns steps and or pulse width with these small increments. Try with some other generator in this price class.SDG1000X have also new Square wave system. It can do 30MHz square or 60MHz square depending model. Try with some other generator in this price class. This new square wave system is more new than SDG2000X what also do not have it. It can produce low jitter square wave also down to very extremely low frequencies. SDG1000 square producle time jitter proportional to period time and with low frequencies jitter rise very big if look jitter time. If look proportional jitter then just around same ballpark with also other brands in this price class but now SDG1000Xmakes it totally different. Because old SDG1000 use comparator method for derive square from internal sinewave. Only way to get better square wave for LOW frequencies with SDG1000 is to do it using pulse function with 50% duty setting for square or other for rectagle. Then jitter is as it is with pulse. Short time p-p just 8ns due to 125MHz clock (aka one clock jitter).SDG1000Xpulse and squarejitter (rms) is 300ps + 0.05ppm of period.SDG1000X have 150MHz and SDG1000 125MHz sample clock. one clock jitter 6.67ns and 8ns. But here need remember that due to new square system and due to EasyPulse system this do not affect pulse (and of course not square and sine).Triangle have this "one clock" time p-p jitter.SDG1000X have also channels output combine function. Not in SDG1000SDG1000X have also harmonics producing function. Not in SDG1000SDG1000X have also user settable variable 50ohm - 100kOhm and Hi-Z outputload impedancesetting.SDG1000X have full channel to channe tracking system. It can track freq, amplitude and phase in combination what user select. With settable "deviation". Exmaple usr can select other channel follow other channel with freg difference. Or amplitue example so that other channel follow 300mV below master channel.Thenin SDG1000X there can select it use phase locked or independent between channels when user change one channel. Phase locked need reset also Ch2 if Ch1 freq is changed. Some times this is unwanted so user can select independent so that it do not DDS reset when user changing frequency.If I do not need all Arb advantages what SDG2000X "True Arb" may give and if 60MHz is enough or better square wave is important then SDG1000X is my selection over SDG2000X.SDG1025 price vs SDG1030X price - still difficult to select?It do not at all mean SDG1025 or what ever SDG1000 is "bad". No it is not.After very early phase some difficulties in signal quality they are corrected. Overall it have beenextremely robustand works without problems.

author: nctnico
author_rank: Super Contributor
timestamp: February 18, 2018, 12:30:12 pm
content: The SDG1000 series has many of the features (like channel settings tracking) you list for the SDG1000X series. I wonder whether the SDG1000 series is still produced at all. Another long standing issue which hasn't been fixed in the SDG1000 is log sweep (which is doing a stepped sweep instead of continuously changing frequency).