Agilent 2000 vs 3000 memory depth - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: February 16, 2012, 02:10:56 am
content: Hi All,First post, (obvious by the counter). Been hanging around quite awhile , great blog. Love the forum. I have to say for a lightly moderated forum the behaviour on here is (with a few exceptions) first class.I am an IT nerd by employment, who used to be more involved in electronics in the very dark past. Also off and on Ham radio nut for the last 25 years or so. When life will allow of course.I decided last year to rekindle the interest in electronics and rebuild the workshop/lab (this blog had a lot to do with that), as I now have the resources to do it and the minister of finance hasn't vetoed anything (yet!). So I decided I needed (would like) a good DSO to go along with the old Tek 2215 I have been using on an off, as its starting to act up and will need some TLC soon. It's old enough that methinks the caps will need replacing sooner than later.Because I like to buy tools only once if I can, I try to buy quality(within budget limitations). I am considering the Agilent scopes. Though I am realistic enough to think they may be over kill for my immediate needs. I just don't like having to replace or struggle with gear because I went "cheap" (subjective term I know). I am thinking that what I buy now, I am likely to have for some years. I am not one to "upgrade" every year or model release, unless it's not doing the job of course.What's my intended use you may ask?.Like most not in the business it is hard to be specific as to its intended use. "Everything" or "don't know" are not particularly useful responses when asked, so I'll try and nail down the possible/probable uses.Ham radio for sure.Micro-controller based projects. I have some things in mind for my car for a start. Fairly new to me, though I did dabble with Z80s back in the early 80s.Learning. It's been so long that I am on a learning curve to refresh the memory. This forum and blog has helped an awful lot there.Plus others that fall into the "everything" bucket.Anyway, to the question. I am considering the Agilent 2000 series or the 3000 series. They mostly tick all the boxes for me.Also,I don't need 4 channels as I don't recall ever having a need for more than two so far. So just 2 channels is acceptable.I think I'd prefer a separate logic analyser so have ignored that feature(I could add it later, but probably won't)From what I have read here it would seem the front-ends are similar/same at least on the lower bandwidth models for the 3000 series.Where I am struggling a bit, is with the memory depth and waveform update rate. I have read a number documents on the Agilent site regarding features etc. As well as searching here and elsewhere. So believe I have a reasonable understanding of the benefits. Dave's comparison with the Rigol certainly demonstrated how useful a fast update rate can be.What I don't have is real world experience. I mean the specs look good. But for those that use either these scopes or their ilk. How often would you run into the limitation of say the 100K depth of the 2000, in your day to day work. Or being in the business you would automatically go for the deeper memory just because you can. Or the boss pays for it so I use what they give me sort of thing.So I thought if I could collect enough data about how often the memory limit was found to be a constraint it might help me decide if I really needed(wanted) the 2MB/4MB of the 3000. I.e, if 10 people used the 2000 but only 2 of those 10 found it a limitation, then it might be very rare that I would find it an issue given my expected usage. I guess it does not even need to be the Agilents at all really. So maybe more generally how often is it a problem. Is memory getting deeper in response to there being an industry need for it. Or is it more a marketing driven feature.I would like to just get the higher spec 3000 series. But the cost difference is significant enough to make me reconsider. I was originally only considering the 100Mhz in either model. Maybe I'd be better off getting the highest bandwidth 2000 series against the unknown navel gazing possibility of needing the increased memory of the 3000. Also I don't think for me the 50K updates vs 1M is a big deal.Of course one big plus for the 2000 is it would likely leave more funds for othertoystools.Most of the other differences between the 2000 and 3000 I can weigh myself as to value. Mostly it's too many $$ and the minister going "it costs how much!!!". She gave trying to understand my need for these sort of things a long time ago.CheersRob

author: grenert
author_rank: Frequent Contributor
timestamp: February 16, 2012, 02:28:42 am
content: I don't have a comment on the memory question, but another price to factor in is any upgrades (wavegen, edu kit, etc). These are more expensive on the 3000 than the 2000, for the same upgrade. Note that at least with the 3000 you may get more with the upgrade, such as arb capability with the wavegen. Also it appears that Agilent is making some upgrades available for the 3k only.If you are learning, you may be interested in the educational upgrade to learn how to use the scope. It's pricey, however.

author: kaz911
author_rank: Super Contributor
timestamp: February 16, 2012, 04:54:16 am
content: I would still select a base 3000 model vs the 2000 model. The EDU kit is the same price. The Wavegen is a bit more expensive but it has ARB capability which the 2000 model Wavegen does not.The 3000 CAN be upgraded to 500 MHz where the 2000 model is limited to 200 MHz.Some dealers will let you buy a 2000 or 3000 with Wavegen and Edu kit with 15% EDU discount despite not being a student. That is what I would try.../k

author: EEVblog
author_rank: Unknown
timestamp: February 16, 2012, 06:21:05 am
content: Well, it's the eternal question really, and the answer, sorry to say, is "it depends".Memory depth IMO is more important than analog bandwidth, and seeing as that you can upgrade the bandwidth on both with an option (3000 to 200MHz only), you could argue that the 3000 would be the better buy up front.But that's obvious when you don't factor in cost.When you do factor in cost? - *throws up hands*Companies like Rigol are now nipping at Agilents heals:https://secure1.ozhosting.com/emona/shop/scripts/prodList.asp?idCategory=56140M points for AU$2KSo you can almost buy a bottom range Agilent 2000 AND a Rigol 4000 for the same price as just an Agilent 3000.Dave.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 16, 2012, 09:53:29 am
content: I find that the primary advantage of deep memory is you spend a lot less time setting up a trigger on a difficult signal, as you can just capture a load of data and zoom in on the detail. Fast update rate is good for catching glitches or infrequent events, however peak-detect acquisition mode at a slower timebase can give some of the same capability, as most of the time the critical thing is knowing there is a glitch, not so much being able to see the exact shape of it.Another reason to go for the 3000 is the potential for license hacks... has anyone yet found a way to recycle trial licenses on the latest FW?

author: cybergibbons
author_rank: Frequent Contributor
timestamp: February 16, 2012, 02:28:59 pm
content: Deep memory can also take the heat off poor or limited triggering. That said - most scopes, even cheap ones, have fairly advanced triggering these days.

author: ToBeFrank
author_rank: Regular Contributor
timestamp: February 16, 2012, 05:42:12 pm
content: Quote from: no_standing on February 16, 2012, 02:10:56 amI was in your exact scenario, and I finally went with the two channel 2000. Don't do it. You think you only need two channels, but once you start really getting into your microcontroller projects, you'll start saying, "damn, I wish I had a couple more channels!". I sold that scope and now I have a four channel 3000. Two more channels and the extra memory depth is totally worth it for me. There have been times already that I wish I had even more memory depth than what the 3000 has. The serial decode options on the 3000 are also nice.

author: ToBeFrank
author_rank: Regular Contributor
timestamp: February 16, 2012, 05:45:09 pm
content: BTW, when you've decided what you want, email or call around to the various vendors and ask for quotes. You'll find you can get a pretty good discount. You don't say where you're from, but if you're in the US also take into account sales tax, which can add up to a lot. I ordered from out of state specifically to avoid it.

author: termi
author_rank: Contributor
timestamp: February 16, 2012, 08:29:32 pm
content: QuoteYes, but now you will have to pay use tax. Otherwise you're a tax cheater

author: ToBeFrank
author_rank: Regular Contributor
timestamp: February 16, 2012, 08:59:56 pm
content: Quote from: termi on February 16, 2012, 08:29:32 pmWow, you are correct! I didn't even know there was a use tax. I've looked it up for my state, and here is what they say:QuoteSo basically anyone who buys online from a site that doesn't collect the sales tax must register and get a license. That's insane.

author: termi
author_rank: Contributor
timestamp: February 17, 2012, 01:28:43 am
content: Yeah, it gets complicated. And I think every state handles it differently. AFAIK here in MA we just report how much we bought out of state with our yearly tax return. I just wonder how many people accurately keep track of what they buy during a whole year.I just wanted to point out that in many cases it's a misconception that you can legally avoid paying taxes by buying out of state.

author: Unknown
author_rank: Unknown
timestamp: February 17, 2012, 08:34:56 am
content: Thanks for the replies guys,@eevblog"it depends" is the eternal answer too, I guess.Point taken on the mem depth. Until you have used it the benefits don't really hit home. I have always gone for the max bandwidth I could afford on analog scopes. I'll have to learn to think differently with a DSO.I hadn't really thought of the higher end Rigol gear. I am still unsure about test gear made in China. In a place I worked years ago I had some bad experiences with the quality and warranty of some computer gear. Worst case was having a poorly made supply fail and cause the system to which it was connected, to burst into flames and nearly burn the clients office down.Worst thing was the "vendor" didn't give a rats.Maybe things have improved now. Most gear I work with nowadays is made by Foxconn anyway (Cisco and most everything else) Also my Mac seems ok.One thing I couldn't confirm was in the specs for the 4000 series it states the waveform update rate is "upto 110,000". Does that mean with all channels active it slows down considerably. A plus for the Agilent is in your review you state that it still manages a 1M/s update.The Rigol price is attractiive, though if I decide on a Agilent they are still doing the 15% off on a trade in till end of Feb. So that makes it a bit closer.@mikeselectricstuffThats's true, I thought about after reading your response and yeah that would be very useful. Beats looking out of the corner of my eye trying to catch the image as it triggers.@ToBeFrankVery good point. I know what you mean.But you do realise you have forced me to bump up the budget somewhat. Would you care to explain that to the minister of finance. "Wasn't my fault dear! he told me too!"Ah!, decisions on how to spend money. It's so much easier when it's not yours!.Rob