Looking to buy an used oscilloscope - Page 1
Forum section: electronics / general

author: d4n13l
author_rank: Regular Contributor
timestamp: January 28, 2016, 04:57:49 pm
content: Hi everyone,So I decided to get into electronics, I'm a hobbyist, but I'm very serious about it yet still a beginner. I've been saving for a while but I haven't been able to find a good oscilloscope for cheap in Mexico (I'm still a student). So, I'm wondering if someone has an used rigol DS1054Z to sell? I considered a new one but shipping to Mexico cost a third of the price! My idea is to get a new one so it last a while.The other options is to see if I can find an old analog oscilloscope that someone would give away or sell it cheap. I've been told you can really learn a lot from them. I would still pay shipping of course, but this way I could buy a new one when I get more advanced.Hope you have something for me.

author: uncle_bob
author_rank: Unknown
timestamp: January 28, 2016, 06:58:13 pm
content: HiA few thoughts:1) Any piece of used gear is likely to come without a warranty. Stuff *does* break. I have *many* piles of used gear that I will get working "some day". Much of it has been sitting for several decades. When I get around to it, I have many examples of the same device. That way I have lots of spare boards.2) A piece of new gear does have a warranty, you need to be sure that warranty is valid. I would be very careful about that if the device did not come from an "in country" source. You can get excellent service from any of these outfits *if* you are covered. A new piece of gear will have fancy features.3) There are things that are projects and there are things that are tools. Projects can wait for years and they don't stop anything else. Tools are the stuff you need to make projects happen. Spending time re-capping a Tek 2465B is a project. That's fine, the result may be a tool. Having to spend time re-building your scope each time you want to use it -- then it's not a tool anymore.4) A power supply is something you must have. A DVM probably is in the same category. These days, I'd put a computer into that same category. Is a scope a "must have"? I seem to have a few (dozen) of them and just bought another yesterday. Ummm errrr .... when was the last time I *used* one? It was lot longer ago (weeks) than when I used a DVM, power supply, or computer. This gets back to how much money to spend on what sort of gear.5) Do you want an analog scope or a digital scope? Each has it's issues. Decoding a few thousand bytes of I2C on a 465 is no fun at all. Basic troubleshooting (for me) is much easier with an analog scope. Analog scopes are going away in the "big world out there". Digital will be all there is at some point. Which do you really want to / need to get familiar with. An older analog scope might have a lot more bandwidth. It also could have a tube that you can only see in a dark room. The same display issue can also come up on an older digital scope. Yes, I have multiple examples of all of that.I know, this is absolutely no help at all in finding a scope. Just more confusion.Sorry about that !Bob

author: tautech
author_rank: Super Contributor
timestamp: January 28, 2016, 07:24:36 pm
content: ^^^^ What Bob said.I'd add that a DSO is much lighter and much less fragile than a CRO to ship.

author: uncle_bob
author_rank: Unknown
timestamp: January 29, 2016, 01:51:08 am
content: HiYes indeed ... when I "unloaded" my Tek 7000 collection it was only practical on a local pickup basis. Scopes "back then" came with carts to transport them on ... I hate to say it, but the big tube based stuff went to an audio guy (and not for troubleshooting).Those were the days.Of course there still were examples back then of guys tossing scopes when the readings didn't agree with what they wanted to see. Did some *major* damage to the wall. Didn't help the scope any either.Bob

author: d4n13l
author_rank: Regular Contributor
timestamp: January 29, 2016, 04:25:06 pm
content: Thanks for the feedback guys. Many of the points you're making are exactly the ones I'm considering. Specially as to what equipment to buy, for instance I decided to make my own power supply. I thinks its a great project to practice and you have the bonus you'll be using it frequently, its not something you will just forget about.As for the oscilloscope, unfortunately I haven't been able to find a good price in Mexico or at least not as good as in the US. However, stuff like warranty is a major concern indeed. So, thinking about that, how likely or often would you say is that an oscilloscope malfunctions?

author: NilByMouth
author_rank: Regular Contributor
timestamp: January 29, 2016, 04:59:48 pm
content: Have you looked at Siglent DSO's? When I started, I bought an SDS1102CNL and it's perfect as a budget beginner scope.

author: uncle_bob
author_rank: Unknown
timestamp: January 29, 2016, 05:38:29 pm
content: Quote from: d4n13l on January 29, 2016, 04:25:06 pmHiAny device you buy *can* go wrong. The most unfortunate way to go wrong has already been mentioned - shipping damage. I have spent a *lot* of time trying to get shippers to pay for the damage they cause. Their "guy" comes out and looks at the packaging. He points to this and that. Pulls out the "rules" and says "they should have packed it better". After a few dozen of these conversations I started looking at the packing on the brand new stuff I buy. It rarely meets the shippers rules ....A lot of the used stuff I get is less well packed than the new stuff. Minor damage is not uncommon. I'd say one large used item in every 4 that I get has some sort of ding or bend in it due to rough shipping.How often do they break after you get them? A lot depends on how much you use them. One of the reasons I have big stacks of whatever I have decided to standardize on is to be able to keep at least one of them running. Best guess - at least one of my bench instruments has some sort of problem each year. Often I have trouble with more than one device. Best guess, plan on tearing into a piece of used gear every 4 to 6 years. The fix most likely will be something minor.How / where / when do I get the bulk of my stuff? Every 10 or 15 years the place I'm working (wherever that is) goes nuts cleaning house. Usually it's because somebody looked at the cost of storage. At that point they go from "let's keep everything forever and ever" to "we have to get rid of all of this". There is not much reason to sort anything. Whatever nobody else wants goes in the back of my truck. Once it gets home I try to make some decisions. The stuff I mostly use comes from the usual auction sites. Yes that sounds weird but it's true. The "throw out" stuff usually is less useful that it might be.On the auction sites I generally spend a few months to a year bidding on things. The last batch of stuff I got popped up a year ago and there has been nothing listed since at less than 10X the price I paid. That's not because I'm smart. It's because I got lucky and I simply refuse to pay crazy prices. Stuff comes out in waves from places like the government. When a batch hits, prices go way down. A year or two later they bounce back up and stay there.My latest scope I bought new. That's a bit unusual for me. I got it mainly because I know (from the name brand on my bench at work) that it does what I need to do about as well as the fancy one. It was *way* cheaper than a used version of the one at work. It also has much more limited specs in areas that don't matter for what I need it for. Like you my biggest concern was shipping and being sure that it got here quickly and cheaply. I spent a lot of time trying to optimize that (without having all the facts). Based on the tracking data, it shipped from a warehouse that is about 5 miles from my home. It's a crazy world ...Again, mostly more confusion ... sorry!Bob

author: Alfons
author_rank: Regular Contributor
timestamp: January 29, 2016, 06:33:11 pm
content: If you buy from a dealer, you have a guarantee, as a rule. So I can buy a Rigol DM3058 as a demo unit and a Grundig Digimess PN300, both for significantly less than 200 €, the Rigol with 1 year warranty, the Digimess with 1/2 year warranty. At least the Surplus Electronic Stores here in Germany usually supply equipment in very good condition with a good service. Much is still quite expensive, but there are also bargains.But Old analogue oscilloscope disappear slowly from these stores...

author: uncle_bob
author_rank: Unknown
timestamp: January 30, 2016, 02:14:08 am
content: HiHere in the US, buying a piece of used gear from a dealer can be "interesting". The typical prices are maybe $3K to $5K on a given scope. The same scope will show up at auction for a tenth of that. Yes you get a very different level of support from the dealer. Unfortunately the delta takes the gear out of the "low cost" range. The net result is that you are comparing stuff like the 1054Z to auction gear rather than dealer surplus.I have no idea at all how this applies to Mexico. I'd bet that it does apply though.Bob

author: d4n13l
author_rank: Regular Contributor
timestamp: January 30, 2016, 05:20:26 pm
content: Not really, there aren't many people as in other countries buying somewhat expensive or specialized equipment. And when they sell it with some use, it's still not so cheap.Anyways I was able to find a please where I can buy the Rigol for the price as in the US and only $20 dollars for the shipment. I think I'll go with it. It'll take about 10 weeks to get here thought u.uThanks for the comments guys

author: uncle_bob
author_rank: Unknown
timestamp: January 30, 2016, 05:25:35 pm
content: HiAs long as the new scope comes with a warranty, it sounds like you have solved your problem. I hope that yours works as well as the one I just got !Bob

author: hibone
author_rank: Regular Contributor
timestamp: January 30, 2016, 10:45:01 pm
content: Look out for retired professionals.Usually they sell good equipment, in good conditions, for cheap.You should get the feeling that they are passing the baton, rather than selling their equipment, so to speak.