Is oscope and function generator in one machine a good choice? - Page 1
Forum section: electronics / testgear

author: goethert
author_rank: Contributor
timestamp: October 09, 2017, 06:56:35 am
content: I just bought a B&K 2540B-GEN. After received it, I noticed it is an oscilloscope with generator. Any pros/cons compared with separate unit? I already have a b&k 4054B generator.

author: JPortici
author_rank: Super Contributor
timestamp: October 09, 2017, 07:43:16 am
content: It depends.There are always compromizes (in the output stage, in frequency and/or memory)For some scopes it is only an aftertought, basic waveforms an mediocre specs in resolution/frequency and aplitudeFor other scope it can be a useful addition, if the ARB is integrated within the scope, for example with the keysight dsox 3000,4000 and 6000 you can grab an acquired waveform and replicate/edit it with the ARB generator, have the scope and the arb trigger together and such things. I find that one to be useful, because the bandwidth/amplitude/specs are okay for what i would have to use it

author: Mr. Scram
author_rank: Super Contributor
timestamp: October 09, 2017, 02:52:00 pm
content: Normally, I'd argue two separate units are generally better than a combined one, but since it's there anyway, there's not harm in using it.

author: David Hess
author_rank: Super Contributor
timestamp: October 09, 2017, 08:26:39 pm
content: If the oscilloscope and its built in function generator cannot operate as a network analyser, then the function generator is useless and just a gimmick.

author: tautech
author_rank: Super Contributor
timestamp: October 09, 2017, 08:44:28 pm
content: Who makes these for B&K, is it Hantek ?The inbuilt AWG does apparently have a sweep function so it might be handy for doing Bode plots like Dave shows how in this vid:https://www.eevblog.com/2012/12/08/eevblog-396-bode-plotting-on-your-osciloscope/

author: nctnico
author_rank: Super Contributor
timestamp: October 09, 2017, 08:48:34 pm
content: Quote from: David Hess on October 09, 2017, 08:26:39 pmI wouldn't go as far as calling it a gimmick but for the extra price you can buy a seperate function generator which usually has easier to operate controls and a much higher output amplitude.

author: David Hess
author_rank: Super Contributor
timestamp: October 09, 2017, 09:00:07 pm
content: Quote from: nctnico on October 09, 2017, 08:48:34 pmAnd with the right separate external function generator and oscilloscope, they can be combined to make a network analyser. My complaint about built in function generators is that they should trivially be able to do this yet except for Keysight and a couple of USB oscilloscopes, none can and these do it poorly.It is the killer application for a build in function generator and they waste it.

author: JPortici
author_rank: Super Contributor
timestamp: October 10, 2017, 10:40:10 am
content: Quote from: David Hess on October 09, 2017, 08:26:39 pmyep.by the way, I only know of the Keysight DSOX and the picoscope (using an external app) which have this capability.Do you know other scopes that can?

author: Hydron
author_rank: Super Contributor
timestamp: October 10, 2017, 01:06:15 pm
content: There are some other niche scopes that do this, but it doesn't seem common. There are also some dedicated devices (e.g. bode 100) which are designed to do only this.I personally know the guy behind Cleverscope, which does turn a sig-gen+scope into a network/frequency response analyser (seehttps://cleverscope.com/fra/for info).He was originally pitching his CS328A scope as a general purpose deep(ish)-memory PC based scope back when they were relatively rare and expensive, but is now much more useful (and marketable - the price for just the basic scope features isn't competitive anymore) as an instrument for specific jobs needing this analysis capability, which was added to the software after the initial design was done.The unit I have has been extremely useful for measuring passives, transformers, resonant circuits, power supply gain/phase and general freq response stuff - it gets much more use than I expected, and I would completely agree about the "killer application" thing (though maybe not about the triviality of doing it well).As for more general purpose scopes, I also have a RTB2004 with sig-gen, which has proven quite useful, but not nearly as good as it could be if the integration was better done (can copy scope waveforms into arb-gen memory, but arb depth/speed is limited, and there is no trigger sync facility). You can do some response analysis stuff using peak-hold FFT and freq sweeps on this scope, but it certainly isn't as good as if they'd written the code to do it properly!

author: Fungus
author_rank: Super Contributor
timestamp: October 10, 2017, 01:47:06 pm
content: Quote from: goethert on October 09, 2017, 06:56:35 amThere's an old expression about horses and teeth that might be applied here.Quote from: goethert on October 09, 2017, 06:56:35 amIt takes less space. If one breaks, they both break.

author: David Hess
author_rank: Super Contributor
timestamp: October 10, 2017, 04:56:17 pm
content: Quote from: JPortici on October 10, 2017, 10:40:10 amHydron mentionedCleverscopewhich looks to me like a product designed by someone who understands oscilloscopes very well andSyscomp Electronic Designalso has several.HP used to make a dedicated low frequency network analyser and might still which could use all three methods, impulse, swept sine, and noise. I usually get by either manually with an external function generator to generate a swept sine or use the impulse method but that requires a DSO which can differentiate and return the FFT magnitude and phase.The recent Keysight DSO which can make swept sine measurements is not any faster than me doing it manually so I have no interest in it. For scalar measurements, it is slower.