Buying an Oscilloscope as a Beginner - Page 1
Forum section: electronics / testgear

author: PCgee
author_rank: Newbie
timestamp: September 11, 2020, 07:09:34 pm
content: Hey all,I am an electrical engineering student who is trying to slowly build up my collection of equipment and currently that includes finding an oscilloscope. Now I've been browsing the web and know that the Rigol DS1045z is an excellent scope for the price and highly recommended and would likely satisfy my needs for many years to come, but I think for now it's honestly somewhat excessive for my needs and more money than I would like to spend.With that in mind I have been proceeding to look for older analog oscilloscopes for sale as I don't really feel like I need to do too much detailed analysis and mostly just need to view the waveforms and take some basic measurement.I watched Dave's video on picking one up for $50 and have been trying to follow the tips but wow has it been difficult. Apparently people in my area don't understand that just cause something is older doesn't make it antique. The only scope I've been able to find on local classified sites (Kijiji and Facebook Buy and Sell) is a Kikusui COS 5060, it is in very good condition but the owner wants $240 (Canadian roubles that is) for it which seems excessive to say the least, and I can't imagine it would be very easy to talk them down much on it. I've checked Ebay and there are some more reasonable options however the prices for shipping is quite insane, often equal to or well above the price the sellers want for the scopes.Basically what I'm wondering is if I should just pony up the money and get something new or if it's worth continually bargain shopping hoping that something pops up I can snag. If you guys have any tips it would be greatly appreciated!Thanks in advance,PCgee

author: sokoloff
author_rank: Super Contributor
timestamp: September 11, 2020, 07:15:21 pm
content: Old scopes are large and heavy. Parcel shipping companies aren’t hurting for parcel flow right now. Unless you find one locally, shipping alone is going to be 25% of the price of the Rigol.I already had an older working Tek scope and still went out and added a 1054Z. Since getting it, I’ve never felt the need to fire up the old Tek. Much more portable, easy computer interface, only complaint is the fan is annoyingly loud.Unless you enjoy the process of bargain hunting (trading many, many hours of time for the hope to save some money), I’d just go get a modern cheap digital scope and be done with it.

author: Fungus
author_rank: Super Contributor
timestamp: September 11, 2020, 07:44:41 pm
content: Quote from: PCgee on September 11, 2020, 07:09:34 pmYou need to look at thedateof that video, things change rapidly. It's also highly dependent on where you live. Some countries have zero options in the second hand market.There's 2-channel 'scopes that are cheaper than the DS1054Z but if you're thinking of doing anything with microcontrollers, etc., then 2 channels isn't really enough.Right now, this is the one to get:https://www.tequipment.net/Instek/GDS-1054B/Digital-Oscilloscopes/?search=trueIt's hackable, etc. and for $310 it's a complete bargain. Plus you get EEVBLOG discount on top of that.Just check shipping/taxes to where you live.

author: MarkF
author_rank: Super Contributor
timestamp: September 11, 2020, 08:12:59 pm
content: As a student, I would not get an analog scope that might have to fix..You might consider the USB scopes that you can just put in your briefcase and go.PicoScope® 2000 SeriesMore expensive but has scope, power supply, function generator and logic analyzer. For those small lab projects.Analog Discovery 2

author: wizard69
author_rank: Super Contributor
timestamp: September 11, 2020, 08:40:26 pm
content: I fully understand not wanting to spend the big bucks on a scope as a student and in most cases would drive people to the used market. It is always advisable to try to get in early on stuff moving to the used world. One way to do so is to look at liquidation sites such a Dovebid. Frankly you can often get rather high end stuff cheap but can get stuck with "lot" sized groups of instruments. It is places like DoveBid where many of the used dealers actually get their stock.Talk to a local ham radio group for feelers about used equipment. Members may have stuff to offer but they also may have handles on local surplus dealers that don't advertise significantly.By the way a storage scope is a huge advantage and frankly you can get decent stuff on the used market. So I'd try to find something that has some sort of storage capability. Even a 20 year old storage scope would be very useful, you just don't get all the fancy computerized functions. In any event to be honest I wouldn't pay much more than $100 for a used low end scope ( less that 200MHz bandwidth).As for buying a new scope It is really hard to suggest doing so for a student. The cost is relatively huge and frankly in most college settings even a modern scope is bulky. This is where it might make sense to get an interim solution like the Digilent offerings:https://store.digilentinc.com/usb-scopes-instruments-circuits/if you can find one. These should not be confused with a full function scope but offer a lot of capability in a small compact device. Frankly I have mixed feelings about Digilents offerings but it is a very well supported system for students and engineers entering the industry. Another option is to go with a USB based scope such as the offerings from companies like Pico, for example:https://www.picotech.com/oscilloscope/2000/picoscope-2000-overview.In either case the idea is to keep stuff as portable as possible realizing that most colleges student have to have a laptop anyways.In any event my post here is to simply point out that there are lots of options out there. What might be a good solution really depends on many factors. If you are early into your engineering program I'd almost certainly avoid investing in a new high end stand alone scope. This mainly because you likely have many things you will need to buy to outfit a repair or engineering bench ( on top of your required school expenses). If you are coming up upon graduation it is an entirely different situation which requires a lot of thought because at this point you should have a good idea where your professional and hobby interests will go. The right scope could be different from what you would buy as a freshman. In any event for a college student I think mobility is a big consideration both in your student years and possibly a couple of years after graduation.

author: TurboTom
author_rank: Super Contributor
timestamp: September 11, 2020, 08:41:27 pm
content: A competitor to the Analog Discovery 2, maybe a tiny bit less powerful and not as well supported, but considerably less expensive,Analog Devices' ADALM2000. Next month available atMouser for 164USD. Maybe worth a thought.

author: pickle9000
author_rank: Super Contributor
timestamp: September 11, 2020, 09:25:49 pm
content: Buying a used scope in Canada is not worth it unless you live in a big city. Even if you find one price can be high. Shipping and so on counts as well.You can get a cheap PC based scope for 100 bucks (like a Hantek on ebay new). That will let you do screen grabs so if you need it for a report could be useful but probably not isolated so be aware of that.Good luck to you sir.

author: GTA
author_rank: Contributor
timestamp: September 11, 2020, 10:10:11 pm
content: Hi. This is my very first post as a new member of this forum. So instead of starting a new post, I'd like to ask some NOOB questions regarding scope input capacitance and probes since I'm in the market for my very first scope.After searching and comparing numerous entry level scopes that suits my budget, I've decided on getting one of Hantek's newer(?) DPO6000B/C/D series scopes.But one thing that's peculiar is that the specification of the analog input channel capacitance is 25pF, +/- 3pF. This is higher than other budget scopes like the Rigol DSO1054Z's 15pF +/-5pF, GWInstek GDS1054B's 15pF, etc... Capacitance values of 15pF is in line with Dave's EEVblog #453 scope probe impedance diagrams, which says to me that these are typical values.Is Hantek's DSO6000 series input capacitance a product of bad design or is this a non issue since the probes they come with should compensate for this higher than typical imedance?Thanks for any comments since I want to pull the trigger next week.BTW, I'm only looking at getting an 50-80MHz model and don't really need anything higher in BW.QuoteWhere can I find that EEVBLOG discount, Fungus?QuoteYou got that right. I've looked around on Kijiji but local ones are snapped up right away or I'd have to pay shipping from another City or Province. Our small market does not offer much, if any choice.

author: tautech
author_rank: Super Contributor
timestamp: September 11, 2020, 11:01:38 pm
content: Quote from: GTA on September 11, 2020, 10:10:11 pmWelcome to the forum.Your understanding of needing a probe that's capable of compensation to the input is correct.However for scopes that have high input capacitance, its effect on a signal when using a direct BNC connection may prove a challenge unless the signal source is of relatively low impedance.Hence we use 10x probes as much as possible so to load the signal source less.

author: PCgee
author_rank: Newbie
timestamp: September 12, 2020, 03:50:25 am
content: I was not aware of the EEVBlog discount at TEquipment, I may have to consider that option. That definitely seems like a great deal but I think I definitely have to evaluate what exactly my requirements are currently before jumping into this, although I suppose a good scope should last me for a decent while.

author: tautech
author_rank: Super Contributor
timestamp: September 12, 2020, 04:28:43 am
content: Quote from: PCgee on September 12, 2020, 03:50:25 amSaelig offer a members discount too and to get the code to enter into their checkout you need ask for it in the Saelig discount thread.

author: Fungus
author_rank: Super Contributor
timestamp: September 12, 2020, 10:56:31 am
content: Quote from: GTA on September 11, 2020, 10:10:11 pmGoogle "eevblog tequipment discount" will get you this thread:https://www.eevblog.com/forum/testgear/eevblog-members-discount-at-tequipment/IIRC the Instek costs under $300 with the discount.

author: Fungus
author_rank: Super Contributor
timestamp: September 12, 2020, 11:00:28 am
content: Quote from: TurboTom on September 11, 2020, 08:41:27 pmI just got an Analog Discovery 2 a couple of days ago. Haven't even had time to play with it yet...

author: SilverSolder
author_rank: Super Contributor
timestamp: September 12, 2020, 02:16:27 pm
content: Quote from: Fungus on September 12, 2020, 11:00:28 amWhere do you even find one, they've been back ordered since forever...

author: Fungus
author_rank: Super Contributor
timestamp: September 12, 2020, 02:53:48 pm
content: Quote from: SilverSolder on September 12, 2020, 02:16:27 pmIt wasn't easy.(I used some connections to get on the 'priority' list and it still took 2 months to arrive)

author: james_s
author_rank: Super Contributor
timestamp: September 12, 2020, 06:04:45 pm
content: IMO the only reason for most people to get an analog scope these days is if somebody gives you one or you find a deal on one that is local so you can go pick it up. I love my old Tek 465B but it's rare that I get it out more than a couple of times a year, for almost everything I reach for the DSO. A few hundred bucks is not much money for a tool that you will use frequently if you are at all serious about electronics.

author: Electro Fan
author_rank: Super Contributor
timestamp: September 12, 2020, 06:20:15 pm
content: Quote from: PCgee on September 12, 2020, 03:50:25 amGood thinking. Have some patience. Figuring out your requirements and options is a good learning experience. When you keep coming back to the same conclusions you will probably have identified the right path forward. It's probably going to be a Rigol or Siglent scope and someday when you have the budget, space, and time youmightfind yourself with an old Tektronix analog scope too. Enjoy the journey, and along the way keep framing your questions and finding the answers. EEVblog is a great place to find answers and ask questions, and share your learning.

author: Fungus
author_rank: Super Contributor
timestamp: September 12, 2020, 06:54:36 pm
content: Quote from: PCgee on September 12, 2020, 03:50:25 amThat Instek for under $300 is a reallyawesomedeal if you're in the USA but for everybody else it depends on how much shipping/taxes you end up paying compared to something bought locally.

author: Electro Fan
author_rank: Super Contributor
timestamp: September 12, 2020, 07:09:44 pm
content: Quote from: Fungus on September 12, 2020, 06:54:36 pmDoes the Instek include serial decoders? It's nice that it has 4 channels, but for a few dollars more it seems like it might make sense to go with the 1054Z or something else that bundles or at least offers serial decoding as an option.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 12, 2020, 07:29:01 pm
content: Quote from: Electro Fan on September 12, 2020, 07:09:44 pmI guess the standard "recipe" if your scope doesn't have decoders is a Saelig (or clone thereof)?

author: 2N3055
author_rank: Super Contributor
timestamp: September 12, 2020, 07:40:26 pm
content: Quote from: Electro Fan on September 12, 2020, 07:09:44 pmIt does. Fungus is right, if you can get small Instek for similar (or few bucks more) as DS1054Z, Instek is very nice scope..

author: MarkF
author_rank: Super Contributor
timestamp: September 12, 2020, 09:47:06 pm
content: A look inside:

author: Electro Fan
author_rank: Super Contributor
timestamp: September 12, 2020, 10:23:58 pm
content: Where does it say what serial decoders it supports?

author: MarkF
author_rank: Super Contributor
timestamp: September 12, 2020, 11:04:01 pm
content: Even scanning the user manual, it does not appear to have serial decoders.

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2020, 05:08:17 am
content: Quote from: Electro Fan on September 12, 2020, 07:09:44 pmYes. It even has a blue button labelled "bus" to turn decoding on/off.(Also note that it has separate vertical controls for each channel...)Quote from: Electro Fan on September 12, 2020, 10:23:58 pmIn the sales brochure, here:https://www.gwinstek.com/en-global/products/downloadSeriesDownNew/1724/130

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2020, 05:30:26 am
content: Quote from: MarkF on September 12, 2020, 11:04:01 pmIt's on page 105:https://www.gwinstek.com/en-GB/products/downloadSeriesDownNew/1681/135

author: rsjsouza
author_rank: Super Contributor
timestamp: September 13, 2020, 12:05:54 pm
content: I suspect the serial decoders are now officially supported in the latest firmware revisions - this is the word of an owner; I don't have one. However, just beware that the same owner reported this function limits its storage memory to 1% of its capacity (from 10M to 100k points only).*For the ones that are ok with the USB oscilloscopes, one alternative is the relatively inexpensive Owon VDS1022 - a two channel 25MHz USB oscilloscope that can be had for less than 100 dollars (US) and, although it does not have stellar specifications, it works well to look at analog signals and its software is well made and a version is being maintained by some other users in this forum.https://www.eevblog.com/forum/testgear/owon-vds1022i-quick-teardown-(versus-the-hantek-6022be)/400/*For the folks that do not understand the storage function for data decoding: think of it as a measure of how many bits the master device sent to the slave device and the oscilloscope could capture and be able to "translate it" (decode) to show in the screen. Depending on its size and the rate to which the oscilloscooe is capturing the data, the storage memory can be filled too quickly to grab any meaningful exchange between the two devices or too large so the information is lost in a very large stream. This is oversimplified, but hopefully it gives some idea.

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2020, 01:54:54 pm
content: Quote from: rsjsouza on September 13, 2020, 12:05:54 pmWhat happens if you grab 10M points then turn on the decoding?

author: SilverSolder
author_rank: Super Contributor
timestamp: September 13, 2020, 02:29:33 pm
content: Quote from: Fungus on September 11, 2020, 07:44:41 pmI like the data logging function, not sure I've seen that in any other scope at any price?

author: rsjsouza
author_rank: Super Contributor
timestamp: September 13, 2020, 07:12:11 pm
content: Quote from: Fungus on September 13, 2020, 01:54:54 pmI have no idea; I am going with what I was told by another user in a somewhat recent discussion. He mentioned the memory was reduced to 100kpts when decoding was enabled.