Which oscilloscope for $100 - Page 1
Forum section: electronics / testgear

author: Greyersting
author_rank: Regular Contributor
timestamp: May 25, 2017, 11:45:33 pm
content: I found 2 oscilloscopes that I am interested in, both are around $100One is the LG EZ OS-5060AThe other is the Tektronix 2213AWhich one would be a better oscilloscope for that price?

author: TK
author_rank: Super Contributor
timestamp: May 25, 2017, 11:56:53 pm
content: +1 for Tektronix 2213A

author: timb
author_rank: Super Contributor
timestamp: May 26, 2017, 12:00:03 am
content: I'd go with the 2213A. It's a decent little 60MHz scope with a delayed timebase. The OS-5060A is virtually identical from a feature perspective, however the Tek will likely have better build quality, is easily serviceable and has a full service manual available. You're also more likely to get help from the Tek Yahoo Group and this forum if you run into trouble.

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 12:10:16 am
content: I'd also go with the Tek. All else being equal it's hard to go wrong with Tek.

author: Greyersting
author_rank: Regular Contributor
timestamp: May 26, 2017, 12:12:17 am
content: Shoot I was hoping I would be told to get the LG. The problem with the Tek is that it's in an auction and is currently $100 with shipping and no bids but I'm sure someone will outbid me. Thanks for the replies.

author: P90
author_rank: Frequent Contributor
timestamp: May 26, 2017, 12:46:24 am
content: or find a Hitachi, excellent scopes and less commonly know, so less expensive than a Tek

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 12:49:33 am
content: I wouldn't be the least bit surprised if nobody outbids you on the Tek, I've bought 4 or 5 100MHz Tek scopes for ~$100 that nobody bid against me on.

author: P90
author_rank: Frequent Contributor
timestamp: May 26, 2017, 01:07:07 am
content: Quote from: james_s on May 26, 2017, 12:49:33 amthat's quite a possibility, since there are so many Teks, and people usually get caught up in bidding wars from a low starting price.I found a Tek2230 for $100 on local craigslost... < lol

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 02:29:04 am
content: 60MHz analog scope, $100 is near the upper end of the value of such an instrument. Few people are going to get into a bidding war on one and if it does happen there will be others.

author: P90
author_rank: Frequent Contributor
timestamp: May 26, 2017, 03:15:01 am
content: Quote from: james_s on May 26, 2017, 02:29:04 amThat's what I was getting at, that most people are going to bid on the ones with a lower starting price, not as likely to bid on one that starts at top dollar.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 26, 2017, 04:23:14 am
content: Get the scope that WORKS, end of story

author: David Hess
author_rank: Super Contributor
timestamp: May 26, 2017, 04:25:00 am
content: Assuming they both work, usually I would recommend the Tektronix but the OS-5060A is at least 12 years newer. If a service manual was available for the OS-5060A, then I would recommend it.The 2213A is likely to need the aluminum electrolytic capacitors in its switching power supply to be replaced soon if this has not already been done.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 26, 2017, 04:57:57 am
content: Japan and Taiwan made scopes get the job done and easier to repair, usually with generic parts.If the LG is a generic rebadge similar to my Kikusui COS5060TM I would gamble on thatTeks are good when they're going,but a royal PITA when they're not.

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 05:01:48 am
content: There are lots of good scopes out there, personally I would offer $50 on something like that and see what they say. $100 is about the top end I'd recommend paying for any analog scope unless it's something specialized that offers a feature you need, or if you need >100MHz bandwidth on a budget.

author: P90
author_rank: Frequent Contributor
timestamp: May 26, 2017, 05:02:16 am
content: Quote from: Electro Detective on May 26, 2017, 04:57:57 amthat is true. Teks are hard to repair unless you are well versed in them.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 26, 2017, 05:07:15 am
content: If I need an analogue scope for work or troubleshooting, I would pay top dollar for a 100% WORKING one, regardless of brand BS.If I want to tinker and frustrate myself in the mancave trying to breathe life into a $50 cheapie, that's a different take

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 05:38:02 am
content: I wouldn't pay top dollar for *any* analog scope. There are loads of perfectly good used ones for $100 or less. If you want cheap, there's always a chance it will have something wrong with it but it isn't hard to test one out.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 26, 2017, 09:01:07 am
content: Top dollar for me is $120 to $600 depending on the bandwidth, and whether it has storage and or readouts, probes and accessories, service/owners manuals etcandMUST WORK PERFECTLY, recent cal cert preferred.A $50 to $100 scope with a seller's semi-BS description is a gamble, and if new players feel 'lucky', I wish them the best of luckBUT,if the 'sounds too good to be true' cheaporetroscope is an intermittent or cal nightmare POS, and gradually trashes their expectations of a useful tool and learning experience,then they are in SOOL limbo,and must face the all too familiar scenario of >"welcome to electronics...have a nice day..."

author: P90
author_rank: Frequent Contributor
timestamp: May 26, 2017, 09:26:58 am
content: Quote from: Electro Detective on May 26, 2017, 09:01:07 amno better way to learn about electronics than to fix that broken pos scope... glass is half full...LOL : )

author: Fungus
author_rank: Super Contributor
timestamp: May 26, 2017, 10:13:05 am
content: Quote from: P90 on May 26, 2017, 09:26:58 am...so long as you have another oscilloscope to do it with.

author: tggzzz
author_rank: Super Contributor
timestamp: May 26, 2017, 10:29:54 am
content: Quote from: P90 on May 26, 2017, 05:02:16 am"Hard" compared with what? Any scope - or other piece of test equipment - is hard to repair if you don't have service manuals and aren't familiar with how they should work. Unlike most brands, Teks have good service manuals available, and there is a very active community just waiting to help.Of course more modern equipment of all types from all manufacturers is more difficult to repair due to custom components and SMDs.But any beginner should get aworkingscope.

author: P90
author_rank: Frequent Contributor
timestamp: May 26, 2017, 10:34:40 am
content: Quote from: Fungus on May 26, 2017, 10:13:05 amtouche´...

author: P90
author_rank: Frequent Contributor
timestamp: May 26, 2017, 10:36:42 am
content: Quote from: tggzzz on May 26, 2017, 10:29:54 amI should rephrase that... as in hard to sometimes source parts for, as opposed to generic components in other scopes...

author: Electro Detective
author_rank: Super Contributor
timestamp: May 26, 2017, 10:45:20 am
content: Quote from: tggzzz on May 26, 2017, 10:29:54 amExactly,get a working one first, get familiar with it,THEN you're ready for the service manual and flow chart progression.You won't learn or get much fixed with a knackered first oscilloscope,sporting 2kv+ fried body parts and a seized heart,whilst poking inside for elusive leaking caps, nuked transistor, burnt transformer, previous owner's lost wallet or stash etcin answer to silent prayers for ANY trace to appear..

author: tggzzz
author_rank: Super Contributor
timestamp: May 26, 2017, 03:50:24 pm
content: Quote from: Electro Detective on May 26, 2017, 10:45:20 amOr for my first scope repair, trying to get the trace todisappear. The scope was doing a passable imitation of a torch, since the grid had become disconnected inside the CRT

author: tggzzz
author_rank: Super Contributor
timestamp: May 26, 2017, 03:52:50 pm
content: Quote from: P90 on May 26, 2017, 10:36:42 amSo you are principally referring to vintagelow-endscopes. Modern and vintage high-end scopes always had many custom components.In any case, many custom Tek and HP components are available from QService and Sphere, or via fleabay.

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 04:01:38 pm
content: I just haven't had any bad experiences like that. I've owned at least a dozen scopes and most of them worked just fine or had basic issues that were easy to repair without any fancy tools or knowledge. It's always a gamble but when you're talking <$100 so what? You take your chances, if it doesn't work either fix it or buy another one. Plenty of adequately tested scopes out there that work fine, maybe they haven't been calibrated in 20 years but so what? I've never found an old scope that was greatly out of calibration, even 40+ year old stuff was still close enough. Scopes are not precision measurement devices.

author: nctnico
author_rank: Super Contributor
timestamp: May 26, 2017, 04:25:36 pm
content: I'd look for a DSO either new (DSO Nano or something similar) or used. Used analog scopes usually are overpriced old junk especially if it says HP or Tektronix on the badge.

author: daveyk
author_rank: Frequent Contributor
timestamp: May 26, 2017, 04:34:13 pm
content: Quote from: Greyersting on May 25, 2017, 11:45:33 pmWhy not just pay $380 for a brand new 200Mhz Siglent with warranty and features out the wahoo? I will be pissing around with a 465B because it was free and I am nostalgic. I am also pissing around with a TDS544A for the same reasons.Sent from my iPhone using Tapatalk

author: rstofer
author_rank: Super Contributor
timestamp: May 26, 2017, 04:34:41 pm
content: I just took a quick look at eBay and it seems to me that the 2213As that might actually work are closer to $200 with one that just recently fell out of calibration running $250.Yes, there were cheaper 2213As but I have to wonder why someone would sell a $200 scope for $100.

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 05:00:52 pm
content: The I'd take a TDS544A over a Rigol any day, that's a 500MHz scope, you're not going to find a new 500MHz DSO that can match it for less than about $2k. As far as why not get a Rigol, well the budget is $100 and that's $385, almost 4x the stated budget. Are you guys gonna chip in to make up the difference for the OP?Seems the scope snobs have turned up here. I don't get it, I would have loved to have something as fancy as a 60MHz dual trace analog scope when I was starting out, I made due with a 15MHz Tek 531A that worked as well as a space heater as it did as a scope. Still managed to get by and learned a lot. Yeah a modern DSO is more convenient but in a lot of cases I think it's a substitute for learning how to actually use the instrument effectively. All scopes have limitations and no matter what you get it's important to understand those limitations and learn how to work around them.

author: nctnico
author_rank: Super Contributor
timestamp: May 26, 2017, 06:04:02 pm
content: Quote from: james_s on May 26, 2017, 05:00:52 pmBe honest: how much did that Tek 531A cost in today's money? Probably way more than $100. For example: I got a brand new 20MHz dual channel analog scope in the late 80's. In today's money it costs about 800 euros.

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 06:46:38 pm
content: I paid $40 for the Tek 531A back around 1992, I suppose that might be approaching $100 in today's money, I don't really know offhand. The point is that despite being relatively low bandwidth and not offering a lot of fancy features it was a usable instrument that I was able to use effectively for a lot of things.

author: rstofer
author_rank: Super Contributor
timestamp: May 26, 2017, 08:01:09 pm
content: Quote from: nctnico on May 26, 2017, 06:04:02 pmThere's a 531A without the plug-in for $169 on eBay right now. There is a complete unit with cart for $440.Before people throw numbers around, they should probably check with eBay and see what working models are going for. Why on earth would a newbie want a 531A with or without the cart? A collector might want one but nobody wants to spend $440 on a 15 MHz scope.It is possible to go to eBay and search for 'oscilloscope' and then sort by price.One scope that just popped up and one I would certainly consider:http://www.ebay.com/itm/GW-INSTEK-Oscilloscope-GOS-6112-2-Channel-100MHz-Includes-power-cord-/332070618956There are 7 left and 126 sold. I think this is part of the school bankruptcy auction. Personally, I would jump on it at $120. ETA: Shipping varies but from Texas to California, it's about $30.ETA2: There are a couple of identical scopes at $80:http://www.ebay.com/itm/GW-Instek-GOS-6112-2-Channel-100MHz-Curser-Oscilloscope-TESTED-and-PASSED/252957412100Problem is, the shipping is outrageous so you're right back at $150.

author: GreyWoolfe
author_rank: Unknown
timestamp: May 26, 2017, 08:09:55 pm
content: if you are looking for a $100 scope, there is a GW Instek GOS-6112 100MHz scope for a starting bid of $79.99 plus $24 shipping. There is 2 hours left to the auction. Watch it and bid at the last possible second to complete the bid and you might just score. No one is even watching it at the moment. I scored one for $90 shipped and I like it.http://www.ebay.com/itm/GW-Instek-GOS-6112-2-Channel-100MHz-Curser-Readout-Analog-Oscilloscope-TESTED-/252947699500?hash=item3ae4db972c:g:SyAAAOSwWxNYt1Zzedit: by the way, if you score it and want the manual, I can email it to you.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: May 26, 2017, 08:15:20 pm
content: I have a Tek 2213a that I bought in Canada about 10 years ago for 125 CDN. I also have a Rigol DS1054z that is two years old and which I use every day. But for some reason I don't want to part with the 2213a. If someone came to the house today with a hundred dollar bill and wanted the 2213a I would not sell.I had to replace a PIN diode and a FET in the front end of the 2213a after a "user error".... it wasn't that hard, either to find the suitable replacement parts or to actually perform the repair, and now it is working perfectly again. If the Rigol had the same kind of fault .... it would wind up in the junkpile for sure.So... "you pays your money and you takes your chances."One thing is certain: If you do buy a used analog scope, make _darn sure_ that it is cosmetically perfect and that all functions work. I bought the 2213a from a place where I could check it out fully before plunking down my hard-earned cash. And since I carried it home on the subway, I was very pleased by its relatively light weight (no heavy power transformer inside.)Those GW Insteks look like pretty good deals too, but I have no personal experience with them.

author: rstofer
author_rank: Super Contributor
timestamp: May 26, 2017, 08:17:07 pm
content: Quote from: GreyWoolfe on May 26, 2017, 08:09:55 pmI see the shipping as $75 with no alternatives offered. Maybe because I am in California?Shipping is always a consideration.

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2017, 08:45:22 pm
content: There is no way that 531A on ebay will sell for the asking price, unless there's something special about it. I gave mine away for free here on this forum and it took some time and effort to find someone who would take it. It's a neat vintage item but the value as an instrument is outweighed by the size of the thing. Ebay is chock full of equipment sitting at fantasy BIN prices, I've seen people asking $1500 for TDS300 series scopes, I've never paid more than $100 for one.

author: GreyWoolfe
author_rank: Unknown
timestamp: May 26, 2017, 09:56:28 pm
content: Quote from: rstofer on May 26, 2017, 08:17:07 pmInteresting, I'm in Florida and it is $23.50 for shipping.edit, Oops, just noticed that it is in north Florida and I am in central Florida. Shipping just might suck.

author: rstofer
author_rank: Super Contributor
timestamp: May 26, 2017, 10:59:31 pm
content: Quote from: james_s on May 26, 2017, 08:45:22 pmBut did you buy them from eBay? For better or worse, eBay is the market. The same equipment is available to any buyer (within some limitations) and shipping is the decider.Certainly there are special ways to come across a scope. I suppose if I heard from someone living in my town I could make them a fantastic deal on a Tek 485. But there is no way I want to get involved in shipping it. My time is worth too much (to me) to bother with such a venture. And I don't need the money...In fact, I got rid of my Heathkit 10 MHz scope by just setting it out on the curb. Somebody took it and I hope they knew what they got. It was a pretty good scope! I sold a scope to a coworker one time. He got a pretty good deal.But I think eBay sets the market price and range.

author: james_s
author_rank: Super Contributor
timestamp: May 27, 2017, 12:01:47 am
content: Yes, as a matter of fact I did, I bought all of the scopes I currently own on ebay along with a couple others I have since fixed up and sold. With exception of the TDS784C they were all $100 or less, and either I was the only bidder or I waited until the listing was almost ended and tossed in a lowball offer of ~50% of the asking price and it was accepted. There are loads of them sitting at sky high asking prices but look at the actual sales of those that sold in auction format (Best Offer sales only show the original asking price) and you'll see that in most cases the real selling prices are far lower than what many people try to get.I think what happens is someone posts something for a high price, then the next person goes and sees that and posts theirs for a similar price and so on. That and hoarders who post stuff at crazy prices because deep down they don't really want to part with it anyway. There have been a number of surplus shops that became little more than a front for a serious hoarder to justify their collecting.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 27, 2017, 12:27:16 am
content: I recently scored locally a nice compact 25 year old dual channel 25mhz scope for 120 au dollars (yes, couldn't help myself, again..) a very novel CRO with built in 9vac component tester, probes, manual etcbecause another buyer did a no show(and the usual breed of leeching low life cheapskates were offering maccas money for it)I could see it had little use as per the sellers description and tested perfect,so I paid the 120, the seller perhaps surprised I didn't bargain(which I'm GOOD at btw)I put it on the bench and used it for a week solid and no issues.If I ever decide to sell it working 100%, I will get $120 for it EASILY,or give it away as parts if it dies and can't be fixed (unlikely, as it's easy to get into, and mostly bog standard parts)If my DSO dies in a non-PSU related way, and more that $200 to fix, it will be given away as parts.FWIW, I don't leave the DSO running all the time because I STRONGLY suspect it won't last 2.5 years, much less 25+ like many old school CROsAgain, if it's a 'first' scope don't be a cheapskate,DO YOURSELF A BIG FAVORand buy a WORKING one regardless of brand.Then you can buy (or dumpster dive) 1000 non working scopes after that, and chances are good you may be able to get a lot of them up and running,or at least calibrate them on the cheap, following the service manual so they are useable,BECAUSE you know how a perfectly~WORKING~scope should work!

author: David Hess
author_rank: Super Contributor
timestamp: May 27, 2017, 12:39:57 am
content: Quote from: Fungus on May 26, 2017, 10:13:05 amWhen someone asks me what an oscilloscope is good for, I tell them they are good for fixing other oscilloscopes.Quote from: rstofer on May 26, 2017, 04:34:41 pmWhen I was oscilloscope hunting, I monitored Ebay auctions for months to get an idea of what they were selling for. I bought my two working 2230s for $60 and $80 respectively. The current sold listings show lots of what look like working oscilloscopes below $100:3x 2213A 60MHz Single Timebase3x 2215A 60MHz Dual Timebase3x 2235 100MHz Dual Timebase2x 2236 100MHz Dual Timebase Timer/Counter2x 2221 60MHz Single Timebase DSO2x 2221A 100MHz Single Timebase DSO4x 2230 100MHz Dual Timebase DSO2x 2232 100MHz Dual Timebase DSO

author: Martin.M
author_rank: Frequent Contributor
timestamp: May 27, 2017, 05:09:31 am
content: Quote from: Greyersting on May 25, 2017, 11:45:33 pmwhy only 2?greetingsMartin

author: Electro Detective
author_rank: Super Contributor
timestamp: May 27, 2017, 07:40:04 am
content: Quote from: Martin.M on May 27, 2017, 05:09:31 amPerhaps close by for pickup?That's how I roll, and I don't trust shipping in general, especially for heavy, easy BREAKABLES

author: David Hess
author_rank: Super Contributor
timestamp: May 27, 2017, 12:24:28 pm
content: Quote from: Electro Detective on May 27, 2017, 07:40:04 amShipping is a big problem which the relatively fragile CRT and front panel controls makes worse and shipping has gotten a lot more expensive over the past couple of years. If you are in a major metropolitan area which includes aerospace and technical companies, then picking up something locally is a good possibility.

author: nctnico
author_rank: Super Contributor
timestamp: May 27, 2017, 01:30:07 pm
content: Quote from: David Hess on May 27, 2017, 12:24:28 pmAnd then let it bump up&down in the booth of your carIt depends greatly on what kind of seller you are dealing with. If it is some kind of equipment dealer they usually know how to pack equipment. Besides that you can always check Ebay feedback to see if the seller knows how to pack stuff or not. The negative and neutral feedback are the most informative.

author: P90
author_rank: Frequent Contributor
timestamp: May 27, 2017, 02:52:30 pm
content: Quote from: nctnico on May 27, 2017, 01:30:07 pmand no matter how well it's packed, FedEx and ups will still manage to fuck it up...

author: Macbeth
author_rank: Super Contributor
timestamp: May 27, 2017, 06:15:58 pm
content: Quote from: Fungus on May 26, 2017, 10:13:05 amYou can use a broken 'scope to fix itself. My very first scope, a Telequipment D51, had a flat line on CH2. I used CH1 to diagnose and repair the CH2 Y amplifier circuit. No multimeter involved

author: Muxr
author_rank: Super Contributor
timestamp: May 27, 2017, 07:19:40 pm
content: My first real scope was the Hameg HM-605. I got it for $85 but with shipping it was little over $100. Love that thing. It needs to be recapped (one of these days I will get around to it). The component tester on it is pretty nifty too, and they are incredibly easy to work on.I love analog scopes personally. They feel good, respond instantly, and look cool while doing it.However it is hard to suggest an analog scope to a beginner today with so many affordable DSO options out there.- DSO single shot capture is a killer feature. Most old analog scopes won't have this, and it's one of the critical functions of the oscilloscope imo.- The badass analog scopes of the yesteryear are way past their drinking age at this point, they are married and have kids. Someone just starting likely doesn't have another scope to do repairs or other gear (sig gens and references) to do calibration on them. It is likely they are in need of recapping at this point.I really think it's worth spending a little more and getting a new entry level DSO, for a beginner. But if you already own a scope and want another one, definitely get an analog scope. They are fun as hell. I am not getting rid of my Tek 465B or my HM-605 any time soon.

author: tggzzz
author_rank: Super Contributor
timestamp: May 27, 2017, 08:52:13 pm
content: Quote from: Muxr on May 27, 2017, 07:19:40 pmYes indeed. The old analogue storage scopes always were a pain in the ass, and were only tolerated because there was nothing better.Having said that, the local Hackspace now has a Telequipment DM63 - adual beamstorage scope so you can capture relationships between transients that are too fast for chopping mode.

author: tggzzz
author_rank: Super Contributor
timestamp: May 27, 2017, 08:54:55 pm
content: Quote from: Macbeth on May 27, 2017, 06:15:58 pmIndeed. I used an HP1740 to diagnose itself when its risetime had mysteriously increased from 3.5ns to 8ns. After having localised the phenomenon, all I had to do was fondle and massage the delay line. Problem solved.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 28, 2017, 12:30:32 am
content: DSOs are downright sluggish and boring, I have one for the single shot capture business even though my analogue storage scope has always done that well enough for my uses.One can question what these cheaper DSOs are really capturing in AD land at certain bandwidths..Noobies should consider getting aWORKINGanalogue scope NOW, get familiar with all the knobs, and see INSTANTLY what's happening on the screen when you probe or hook something up.If you do buy one, get it locally,PICK IT UP YOURSELF,and get it home like you would a newborn baby(whether it's yours or suspect foul play)

author: P90
author_rank: Frequent Contributor
timestamp: May 28, 2017, 01:30:46 am
content: Quote from: Electro Detective on May 28, 2017, 12:30:32 am

author: james_s
author_rank: Super Contributor
timestamp: May 28, 2017, 02:00:11 am
content: I would have agreed for a long time, however DSOs have gotten quite good and now you can get one for a reasonable price that performs as well as an analog scope for most things, however I would say a cheap analog scope is better than a cheap DSO, analog scopes all work pretty much the same way but the performance and usability of DSOs varies widely. I still always suggest someone learn on a basic analog scope if possible, but it doesn't have to be anything fancy. It forces you to understand how the instrument works and how to take measurements reading the graticule and then when you get a DSO all that stuff will seem so much easier and you'll have the background understanding. If you need bandwidth, analog still offers the most bang for the buck, but if 100MHz will do there are lots of cheap DSOs around now. I've bought several TDS340 DSOs and never paid more than $100 for one.

author: tggzzz
author_rank: Super Contributor
timestamp: May 28, 2017, 06:18:49 am
content: Quote from: james_s on May 28, 2017, 02:00:11 amAll that is relevant and valid, but I'd add a couple of points.Analogue scopes have all the controls on the front panel, not hidden 3 buttons deep in a GUI. That'simportantfor beginners, andhelpfulfor the experienced.I've used a Tek TDS340 and it has significant limitations compared to an analogue scope: short memory (so can't scroll along a waveform looking for glitches) and no peak-detect (so averaging can hide transients and noise).

author: Electro Detective
author_rank: Super Contributor
timestamp: May 28, 2017, 08:29:45 am
content: It's good to see some agreement on the value of a WORKING analogue oscilloscope for noobs, and experienced users.The DSOs have their place, once a user is familiar with scopes in general,who can then can ~patiently~ waste time looking for an elusive function or trigger thingie,usually hidden in some 10 pages deep Ambiguity Menu..whilst trying to fix some intermittent PITA POS DUT(that's almost due to be wave soldered into oblivion, with a heated and pre-fluxed 600 watt sledge hammer)

author: P90
author_rank: Frequent Contributor
timestamp: May 28, 2017, 08:34:11 am
content: all the more reasons I like equipment with lots of knobs, buttons, and indicator lights...

author: Electro Detective
author_rank: Super Contributor
timestamp: May 28, 2017, 08:53:15 am
content: Quote from: P90 on May 28, 2017, 08:34:11 amI like it when ladies roll that way too

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2017, 09:42:50 am
content: Quote from: nctnico on May 26, 2017, 04:25:36 pmI have no axe to grind in the Analogue vs Digital debate - I grealty value the speed of a decent Analogue scope for signal integrity (I have a Tek475A) and the convenience of single shot on a DSO.I just wanted to chime in and say for heavens sakeDon'tbe suckered into buying a "DSO Nano or something similar", they're single channel 1Msps toys. If you must go for a DSO for $100, then I would (and did) go for a USB Owon VDS1022(I). Even the lowest end Hantek 6022be would be preferable to a Nano.Now back to the discussion of the other options...

author: Electro Detective
author_rank: Super Contributor
timestamp: May 28, 2017, 09:52:19 am
content: Quote from: Gyro on May 28, 2017, 09:42:50 amThat's one very useful chime inThose nano DSO NoNos don't even rate for a sledge hammer warm up session

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2017, 10:14:02 am
content: Quote from: Gyro on May 28, 2017, 09:42:50 amThere isn't much choice in the $100 area if you want to buy new. The Owon and Hantek are both USB scopes. Ofcourse the DSO nano is a toy but it is not the only device out there which is why I wrote 'something similar'.

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2017, 10:20:25 am
content: I don't think you'll find ANY new non USB DSO in the $100 bracket that isn't EXACTLY similar to the nano.Yor preference for DSO over Analogue is very well known (taking the latest 'Which scope' thread as today's example). DSO over Analogue, maybe. DSO atany price? No way!

author: tggzzz
author_rank: Super Contributor
timestamp: May 28, 2017, 11:11:22 am
content: Quote from: Gyro on May 28, 2017, 09:42:50 amPrecisely. "Horses for courses", and "the right tool for the job". Not difficult, really.Anybody that insists that X is always right (or all you need) should be treated with suspicion.

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2017, 11:35:47 am
content: Quote from: Gyro on May 28, 2017, 10:20:25 amName something an analog scope is better at (and don't come up with something which is due to people staying stuck in old habits)!

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2017, 11:54:44 am
content: QuoteHuh?Ok, Bandwidth for one!Pretty much any used, working, Analogue scope in the $100 range is going to perform better than a DSO Nano (200kHz 1Msps) 'or similar'. You still haven't provided any evidence of what 'similar' $100 DSO exists that isn't as poor as a DSO Nano.There is nothing wrong with USB by the way, if properly implemented. The VDS1022 does it well, the Hantek much less so.I made it perfectly clear that I have no axe to grind regarding Analogue vs DSO, I have and use both.To advise someone with $100 to spend to buy a DSO Nano 'or similar' (if you insist on some wriggle, not wiggle room). IsBad Advice!I am simply calling you on it.

author: bsalai
author_rank: Regular Contributor
timestamp: May 28, 2017, 12:15:58 pm
content: But that's the great part. You will need to get another scope to fix the first one, and if you are lucky, yet another's one to fix the second one. Just ask some of the folks here how many they have. It's enough to make you drink, which by the way is easier to quit!Soon, your spouse and kids will have left and you will be living in your basement. At least your scopes will keep you warm.Sent from my iPhone using Tapatalk

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2017, 12:17:18 pm
content: I did say working.

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2017, 12:42:37 pm
content: Quote from: Gyro on May 28, 2017, 11:54:44 amI'm quite sure the DSO Nano (or similar) would be a great help back when I only had a 20MHz analog scope. Perhaps you could elaborate why the DSO nano is such a bad choice.

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2017, 12:55:37 pm
content: Err, because it'sSingle channel, 200kHz (at best!) 1Msps of course.That's a catastrophically bad deal compared to what else you could buy for the same money. As you said yourself"It's a toy"!Ok, if you want to stay in the DSO domain then the VDS1022 is [Edit: 2 channel] 25MHz (verified) 100Msps. A working second hand Analogue scope of ebay would get you 50-100MHz [Edit: 2 channel] for the same price.It depends whether repetitive bandwidth or single shot is more important to the OP.Surely you can't still be claiming the the DSO Nano (or unidentified 'similar') is good advice?

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2017, 01:03:29 pm
content: Quote from: Gyro on May 28, 2017, 12:55:37 pmBut now you are looking only at bandwidth. I'm looking at doing single shots, low frequency signals, measurements, storing screenshots, etc. IOW: everything an analog scope sucks at. The right choice depends on the intended use of the OP.

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2017, 01:15:34 pm
content: QuoteThat's exactly what I just said. I mentioned both bandwidth and single shot. The VDS1022 has single shot, measurements, storage etc etc, has twice as many channels and is 100 times the sample rate of the DSO Nano. If the OP wants repetitive then he can have about 500 times the bandwidth of the DSO Nano (4 times the VDS1022) with an analogue.In neither OP choice scenario does the DSO Nano make any sense whatsoever! There are times when you're at the bottom of a hole and you really need to stop digging, at least while people are watching!

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2017, 01:59:56 pm
content: Indeed. Why would a small portable solution always be worse than one which needs at least a laptop.

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2017, 02:03:29 pm
content: Because it's a "Toy" rather than a useful piece of test equipment.Maybe you like the user interface though its pre-modification MP3 player buttons?Any other objections while we're here?

author: Fungus
author_rank: Super Contributor
timestamp: May 28, 2017, 02:09:08 pm
content: Quote from: nctnico on May 28, 2017, 12:42:37 pmI've used my DSO Quad twice this week. It's horrible to use and only about 10MHz bandwidth but it fits in a pocket and is battery powered. Both times it showed the problem, both times it was the right tool for the job.Quote from: Gyro on May 28, 2017, 12:55:37 pmA "Quad" is 2 Analog+2 digital channels, 10MHz-ish.

author: Fungus
author_rank: Super Contributor
timestamp: May 28, 2017, 02:11:41 pm
content: Quote from: Gyro on May 28, 2017, 02:03:29 pmIhatethe user interface but it's a useful tool if that's all you've got or can't use a real 'scope because you're outdoors.

author: Gyro
author_rank: Super Contributor
timestamp: May 28, 2017, 02:21:35 pm
content: Certainly a Quad might be useful out in the field when nothing else is available. It remains to be seen whether the OP is outdoors or has a bench. From his original scope suggestions I would hazard a guess that he has a bench (and a computer).

author: timb
author_rank: Super Contributor
timestamp: May 28, 2017, 02:32:08 pm
content: Quote from: nctnico on May 28, 2017, 01:03:29 pmTo be fair, you can do single shot *and* "screenshots" with an analog scope by simply using a digital camera. (Okay, it's a pain and the ass and I wouldn't want to do it every day, but in a pinch it *does* work.)

author: David Hess
author_rank: Super Contributor
timestamp: May 28, 2017, 02:42:43 pm
content: Quote from: nctnico on May 28, 2017, 11:35:47 amDoes that include a comparison against digital storage oscilloscopes which should be able to do something but are broken by design?Given the choice, I would recommend a reliable DSO but if the cost needs to be as low as possible for a given level of performance, then a used analog oscilloscope is going to deliver more.1. RMS noise measurements (1) - Rigol's RMS measurement function is completely broken as far as noise measurements and I assume this is because of making measurements on the already processed display record but I wonder if Keysight's DSOs which do the same thing have the same problem. This makes points 2 below more difficult to evaluate.2. Noise - Dave made a video which discussed whether analog oscilloscopes had less noise but he did not make any quantitative measurements. Comparisons between my own measurements on analog oscilloscopes and various quantitative reports from EEVBlog indicate that modern DSOs usually do have a lot more noise than they should.3. Add and invert differential measurements on an analog oscilloscope do not suffer from multiplied quantization noise. (2)4. You can get a lot more bandwidth for a given price from a used instrument and used analog oscilloscopes are more repairable than used digital storage oscilloscopes; most of the later lack service documentation.(1) It is a little counter intuitive that RMS noise measurements can be made on an analog oscilloscope but it is surprisingly easy to do using the tangential method and accuracy and repeatably are good. This is time consuming compared to an automatic measurement on a DSO but many of them cannot make this measurement accurately at all even though they should be able to.(2) Some very old DSOs do not either because they do the subtraction in the analog domain before quantization. A differential probe solves this problem and has other advantages but they are not inexpensive.

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2017, 04:14:16 pm
content: You can circumvent using pre-processed data by choosing the timebase so that the actual samples are used for a measurement. Besides that many DSOs have FFT which could tell you something about the frequency spectrum of the noise as well. When doing differential measurements using 2 channels I always had more trouble to get the vertical range setup in a way I still got some visible signal without overdriving the input. Also DSOs have averaging, hi-res or (even better) input filtering which cleans up noise from a signal nicely.I'm not so sure about cheap high bandwidth either. I've owned my fair share of high bandwidth analog scopes but the really high bandwidth ones went for fairly high prices. Nowadays a Tektronix TDS500 or TDS700 series is a good choice if you want a compact 500MHz DSO for relatively little money. The service manuals including schematics are available and many people know how to repair these. The same goes for many older Lecroy DSOs but these are larger and heavier.

author: David Hess
author_rank: Super Contributor
timestamp: May 28, 2017, 06:12:11 pm
content: Quote from: nctnico on May 28, 2017, 04:14:16 pmIf I understand what you wrote correctly, a long record length would make this worse. Won't that be a marvelous opportunity for marketing to advertise their shorter record lengths and lower sample rates which will allow accurate RMS measurements to be made.Or they could just fix it. It is not like we have not known how to make reliable RMS measurements on DSOs (and sampling instruments) for decades.QuoteThis would be more useful if one could take for granted that DSO FFT functions worked to make absolute quantitative noise measurements. Almost all fail and offhand I do not know of any which work correctly. ThisEDN articlediscusses the problem.I do not have any DSOs with an FFT function that I trust for this so at low frequencies, I use a 7A22 to make absolute RMS spot noise measurements. Then with some math I can usually derive the 1/f noise corner frequency. None of the budget DSOs I have tested could make this measurement with their FFT function.QuoteThat is definitely a problem and one of the reasons that better oscilloscopes place the overdrive limit outside of the visible display. One of the tricks to getting good results on an analog oscilloscope is to use the variable function on one channel to exactly match the gain of both channels; to me it is eerie to see the visible noise suddenly decrease to a minimum when CMRR (common mode rejection ratio) is maximized.QuoteAveraging and high resolution acquisition mode are very powerful functions. Input filtering is common on all oscilloscopes to one extent or another.QuoteThe only service manual schematics I am aware of are for the old TDS series are for the TDS520. Back when I was looking for an inexpensive used DSO, I stayed with the 2230/2232 and 2440 series for this reason despite their disadvantages. The known problems with many of the TDS series like leaking capacitors was a factor also.Despite their low used cost, I tend not to recommend the 2230/2232 or 2440 series to beginners. They meet my minimum requirements for a DSO but their age makes for low reliability and beginners are not likely to be in a good position to maintain them.

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2017, 06:30:49 pm
content: The Tektronix TDS500/TDS600/TDS700 are basically all the same when it comes to the things that break often. AFAIK there are some TDS600 series services manuals out there as well. I've worked on a few of these which I bought with a defect and the TDS520B component service manual always got me where I needed to be. However with any repair: you have to have a talent to fix stuff when it comes to complicated problems because a schematic doesn't tell you which component is bad.

author: daveyk
author_rank: Frequent Contributor
timestamp: May 28, 2017, 06:37:28 pm
content: Quote from: nctnico on May 28, 2017, 06:30:49 pmI'm still going to piss around with that TDS544A. I ordered an entire front end for it; payed $54. If that don't fix it, then the acq board still has problems. I replaced all caps and scrubbed the board with simple green and ISO. So now I know who to ask for help - lol.Sent from my iPhone using Tapatalk

author: james_s
author_rank: Super Contributor
timestamp: May 29, 2017, 05:41:11 am
content: Quote from: tggzzz on May 28, 2017, 06:18:49 amI'm not sure I follow. How are those things limitations compared to an analog scope? Analog scopes don't have *any* memory, and I'm not sure peak detect is a concept that has an analog counterpart. A CRT provides the same averaging that hides transients and noise. That's why DSOs tend to look noisy and glitchy.Also I would second the comment that the DSO Nano things are toys, and marginally useful at best. Can't really compare the price though as the nanos are new, and you're not going to get a decent *new* scope for $100, analog or digital.There are plenty of $100 or less scopes out there that are reasonably good though. You can get 100MHz in either analog or digital form within that budget. Much beyond 100MHz and analog starts to have a significant price advantage.

author: David Hess
author_rank: Super Contributor
timestamp: May 29, 2017, 12:05:34 pm
content: Quote from: tggzzz on May 28, 2017, 06:18:49 amThe TDS340 manual and specifications say that it has peak detection.

author: tggzzz
author_rank: Super Contributor
timestamp: May 29, 2017, 03:50:50 pm
content: Quote from: David Hess on May 29, 2017, 12:05:34 pmMaybe I've misremembered; it has been a while since I used it and I was only interested in risetime. I'll check when I next have access to it.

author: james_s
author_rank: Super Contributor
timestamp: May 29, 2017, 04:18:39 pm
content: The TDS340 does have peak detection, I have one right here. As to whether it works well I can't really say, it's not a feature I've used much.