About to buy Tektronix 475.First oscilloscope so need price advice! - Page 1
Forum section: electronics / beginners

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 21, 2016, 10:17:52 am
content: Hi all,I'm about to get a Tek 475 w/original probes and manual for about 150€ or 170$ (local pickup).Seller says that the scope is working okay and shows pictures of it displaying two sines.Traces seem nice and clear and the scope seems fairly clean.I know the price isn't great (and not negotiable) but the guy's local and he will bring it to me so I'm thinking about it..Should I pass and search for a 2235 or similar or I should just go for it?I was considering a 465/475 mainly because these are supposed to be more serviceable than the other Tek scopes.Thanks!

author: EEVblog
author_rank: Unknown
timestamp: August 21, 2016, 12:40:19 pm
content: Why do you want and old analog scope as your first scope?Modern digital scopes are much more useful.

author: homebrew
author_rank: Frequent Contributor
timestamp: August 21, 2016, 01:10:40 pm
content: It pretty much depends on what you want to do with the scope.15 years ago, I also bought a used analog scope of this area (Philips PM3216 - also my first one at the time) and still use it often today. It's just a handy tool to roughly look what is going on ... But at the time it was THE absolute eye-opener for me to be able to really "see" what was going on with my signals. With that tool, my enthusiasm of the hobby really skyrocketed ...However, today I would certainly directly buy a DSO. Probably one of the Rigol ones, as they have exceptional price/performance and large sampling memories. These can be obtained at just nearly twice the price of your offer - so yeah, as you already mentioned, the offer is not really good, given the alternatives ...

author: asgard20032
author_rank: Regular Contributor
timestamp: August 21, 2016, 01:11:33 pm
content: When I was looking to get an analog scope, I wanted a good one for sure. So I looked up for tektronix 2465b and the like. Those scope has problem with the built-in battery, that keep the config ram alive (it is an analog scope, but with some digital feature). If you loose the config setup... Well, it is a fully non calibrated scope. So if you really want an analog scope, either buy an older analog without any digital feature, but also less powerful, or be sure you know how to change the battery without loosing calibration, or how to calibrate it yourself.Or just buy a modern scope, where everything work.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 21, 2016, 01:55:43 pm
content: I prefer an analog scope cause I like the crt screens better and I'm also going to use it for audio signals (synthesizers etc).A lot of opinions floating that for audio you don't particularly need a digital scope,analogs are cheaper and well built and if they work they can perform just fine.I like digital scopes as well (esp. agilent DSO2xxx) but these are going for more than I can afford right now and even 300-400€ for a low end Rigol is too much at the moment.?nother reason is that analog scopes look better IMO.:)You just got to have one.!Although I agree that DSOs are much more useful and easier to use and maintain.A DSO is definitely on my buy list this year after I save up for it and practice with an analog first.I'm in Greece so US prices do not correspond to the EU ones for used scopes so I know that I should probably wait for something around the 100€ mark but I'm probably going to go with the 475 and just save for a DSO while learning and experimenting with what I have.Seller will include a bunch of connectors and bnc cables so that might not be that of a bad deal.I just want to make sure that the 475 is still a solid choice regarding analog oscilloscopes or I could really do better.about that Dallas rtc chips there is a guide somewhere for replacing just the battery.I've done it myself on a couple of old pentium I motherboards.You just have to file down the chip in the correct spot to expose the CR2032 legs ; cut them and solder a battery holder on top of that.Google it ;there's plenty of info on vogons.org.

author: rstofer
author_rank: Super Contributor
timestamp: August 21, 2016, 02:01:39 pm
content: The Tektronix 4xx series scopes are excellent. I have been using a 485 for the past 12 years and I don't plan to get rid of it any time soon. I paid about $200 on eBay. The price of $175 for the 475 seems right; I wouldn't quibble.OTOH, I bought a Rigol DS1054Z a couple of months ago and it is now my go-to scope. I wanted 4 channels with serial decoding and I was willing to give up bandwidth to get them. The single-shot feature alone is worth buying digital over analog.But if money is tight, a lot of electronics can be done with the 475. You need to be a little more clever in coming up with ways to make patterns repetitive and sometimes you need to rig up a special trigger signal but there was a time before DSOs and, as I recall, we put 12 men on the Moon. Just saying...You will soon start to get advice that seems a lot like chasing this scope thing down a rabbit hole. If you expand your budget to $400, the 1054 is excellent. If you expand it to $1100, some other model is even better. Heck, for about $150,000 you can get the top of the line. I suggest you drive a stake in the ground at your budget and don't deviate. You'll get a lot of advice like "... for a few hundred more ...".But Dave is right, DSOs have features that make them much more capable than analog. But sometimes, we need to take a step back and realize that this is a hobby, not a second career. And this is the first scope, it doesn't have to be the last one. In the meantime you can learn a lot about scopes and not break the bank.Good luck!

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 21, 2016, 02:33:01 pm
content: Very positive post rstofer !You're spot on about people always wanting more without taking that step back and see that they really could get by with less.That said,it's not that I won't buy a DSO at some point; it's that I prefer the nerdy feel of the analogs for my first one, and the money is really tight atm anyways.Besides,if you're in for a digital scope you may really have to spend the extra buck if you want a little more longevity or extra features and that can indeed lead to greater dilemmas and expenses so I could postpone that until I have some dough saved.I wouldn't commit to buy an inferior DSO just for not having some extra money but for analog I don't feel bad doing a similar thing (settling for not the greatest deal).Maybe because analogs can't get any better anymore and I think that 475s were top class at their age.Digital becomes obsolete faster ,although I think that for most hobbyists there are plenty of good value/performance choices these days.Only thing I fear is that after cleaning the scope and everything I'll need to educate myself on how I should test its accuracy and functions or worse even calibrate this thing!I really wouldn't know where to begin if calibration is needed but I'm not touching anything until I get things straight,don't want to do more harm!

author: tggzzz
author_rank: Super Contributor
timestamp: August 21, 2016, 03:34:24 pm
content: Quote from: homebrew on August 21, 2016, 01:10:40 pmThat'sthemost important question, of course!QuoteWho cares what the price/performance ratio ofanythingis? That's something marketeers dream up to convince PHBs (and preferably "upsell" to them!).What matters is:does it do whatIneed it to do inmyapplication?canIafford it?is there a significantly cheaper choice that will fulfilmyneeds?

author: tggzzz
author_rank: Super Contributor
timestamp: August 21, 2016, 03:42:47 pm
content: Quote from: EEVblog on August 21, 2016, 12:40:19 pmThat completely depends on what you want to use the scope for.If you are looking to see why your "digital" circuit is operating intermittently, the 200MHz bandwidth of a 475 is averysignificant improvement over a 50MHz bandwidth. Even 35 years ago, 100MHz was marginal for such purposes, and jellybean logic is faster now.OTOH, if you are looking at startup transients, the bandwidth is relatively unimportant but the capture/storage is the key feature. it is an unconvenient truth that almost all electronic circuits are actually analogue, the common exceptions being femtoampere or photon counting applications.

author: tggzzz
author_rank: Super Contributor
timestamp: August 21, 2016, 03:44:17 pm
content: Quote from: asgard20032 on August 21, 2016, 01:11:33 pmTrue, but completely irrelevant in this case (a 475).

author: oldway
author_rank: Super Contributor
timestamp: August 21, 2016, 03:45:11 pm
content: For audio applications, you don't need a 200Mhz scope, 20Mhz is more than enough.In Europe, I think you better buy an Hameg analog scope (easier to repair if necessary) than a Tektronix one.I think that something like an Hameg HM412 two channels would be a good choice for you.I recently buy one for 40€ with probes for a friend of mine.Hameg HM203 and HM204 are also good options.My prefered Hameg analog scope is the HM605.If you choose Tektronix, I recomand the 465B or the 2235.Those old analog scopes don't have any ram nor built-in battery.

author: tggzzz
author_rank: Super Contributor
timestamp: August 21, 2016, 03:58:05 pm
content: Quote from: belzrebuth on August 21, 2016, 02:33:01 pmGlad you've spotted that. The adviceissound.QuoteA true engineering attitudeQuoteMake sure it really is working. Ask whether it has been "recapped" - electrolytics can degrade with age, and sometimes (not always) need to be replaced.At the very least use a probe to look at the 475's calibration signal. You are looking to see both channels show a deflection on all ranges, and that you can trigger stably on all timebase ranges. The amplitude, frequency and risetime are not well defined, since the cal out is only intended to be used to trim *10 probes.QuoteYou would download the manual and follow the instructionsWith a little understanding and imaginateion, you will realise you don't need the exact equipment specified...To calibrate the x axis you need an accurate (i.e. <2%) frequency source. Any cheap DDS is sufficient.To calibrate the LF y axis you need a PSU and multimeter.To calibrate the HF response you need a digital signal with risetime of ~1ns. I use 1 74LVC1G* gate, well decoupled, with short wires.

author: tggzzz
author_rank: Super Contributor
timestamp: August 21, 2016, 04:00:25 pm
content: Quote from: oldway on August 21, 2016, 03:45:11 pmThe 465 does not have any advantages over a 475 - and the 475 has a higher bandwidth, which is important for some purposes.

author: tggzzz
author_rank: Super Contributor
timestamp: August 21, 2016, 04:03:59 pm
content: Quote from: belzrebuth on August 21, 2016, 10:17:52 amHP1740s and 485s are noticably better in that respect than the 465/475. I'm unpleasantly surprised at the construction techniques of the 465 and 475 - but that shouldn't stop you from buying a working 475 (or 465).

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 21, 2016, 04:25:08 pm
content: @oldwayI very recently lost an auction for a 2230 which ended at 100 including shipping.I didn't raise my max bid enough so someone snipped it from meThat was maybe the cheapest (listed as fully working) 22xx I saw the past month on eBay.(from EU)I very much like the form factor of the 223x s but their prices often exceed my $$ limit.I often see them go at about 200€ with or without shipping and most of them are listed without any accessories , "sold as-is" or "turns on" etc..People seem to like them and they're popular so they seem to be going for higher prices than they're used to.I think that 22xx series are the first that comes to mind when someone searches for an old scope on eBay.US scope prices are much lower but I'd have to pay high shipping and tax fees so it's a no-go.Unfortunately I can only shop from eBay because in my country you can't really find used scopes for a good price on the craigslist equivalent.I was looking for Hameg too but Hameg scopes are also going for higher prices on eBay,maybe because EU sellers often list them so EU buyers consider them a cheaper (shipping-wise) alternative to Tek scopes.They pop up on eBay (german) regularly for attractive starting bids but most end at about 150 or so and I'd have to pay about 25-50€ shipping so we're again at about 200.Also most hameg scopes I see on eBay are 20mHz or 60mHz and the 475 is 200mHz.I certainly don't think I need a 200mHz scope at this point but I don't think I could find a much better deal on a Hameg,except if I wait long enough and constantly check eBay listings.@tggzzzThanks for all the tips!!I really appreciate it.I asked if the scope has ever been calibrated but the seller said it wasn't cause it worked okay so far so he didn't bother.I know that's vague but that's all I know so far.I also asked if he ever recapped it or replaced any components and guess what;Yeah !He didn't.So I will probably have to check the state of filter caps and check voltages too.I hope that since this is a working unit I won't have to mess a lot with it but who knows.I think that I have to get one or two of these cheap function generators I see on eBay and just feed some signals in to see if everything shows as it should.Asked the seller to bring a function gen with the scope in order to roughly check both channels before I buy it.

author: tggzzz
author_rank: Super Contributor
timestamp: August 21, 2016, 04:50:31 pm
content: Quote from: belzrebuth on August 21, 2016, 04:25:08 pmIf front panel lights are visible but a trace isn't, it means any/all of the HV, EHT, CRT are faulty, and maybe more. HV can be repaired, EHT and CRT are more problematic. If there are no lights then itmightbe only a faulty capacitor.QuoteYou're welcome.If it works, it works - and anything you do might make it worse. No surprises there. The easy check is to measure all the power supply voltage railsandthe AC ripple voltages - both listed in the manuals. Poor caps often show up as high ripple. Tantalum beads often fail short-circuit, and that trips the entire PSU. There is a lot of information on how to choose replacement capacitors; search this forum and Yahoo! TekScopes.If you know how to use a scope, having a function generator there will be a great help. You can regard the "cal out" as a very simple function generator, and even that will greatly increase your confidence.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 21, 2016, 05:01:52 pm
content: @tggzzzSadly I don't know how to use a scope (yet!) so I may have to read up a little tonight to be prepared!I found a pdf online "oscilloscopes and how to use them" so I'll give this a go.If you happen to have any recommended (mostly hands-on) references or YT videos on explaining basic oscope usage please share:)I've watched a lot of YT videos these days tbh but I haven't quite grasped the whole concept of using a scope.Of course having one nearby and get experimenting while reading or watching stuff would greatly help,I don't think you can really familiarize with these concepts otherwise.Still though,any resources offered will be of great help!

author: rstofer
author_rank: Super Contributor
timestamp: August 21, 2016, 05:11:11 pm
content: Quote from: belzrebuth on August 21, 2016, 02:33:01 pmThanks!QuoteI haven't even taken the cover off of mine.I consider a scope to be a squiggly line display device, not a precision measurement machine. The voltage scales are about right (actually, I haven't seen a measurable error) and the time/div seems right given that I usually know the frequency. Realistically, the scope could be off a bit and I wouldn't be able to resolve it on the screen anyway.If it displays both traces and the controls seem to work, I wouldn't be in a hurry to take it apart.You can test all of the controls from the probe compensation source on the front panel. You could also test it with a couple of batteries with known voltages. If you get to test before you buy, why not brink along a 1.5V and 9V battery?Squiggly lines...

author: oldway
author_rank: Super Contributor
timestamp: August 21, 2016, 05:15:14 pm
content: Quote from: tggzzz on August 21, 2016, 04:00:25 pm465 is simpler than 475 because 475 has two-non delaying sweep generators (A sweep generators) with complicated switching.One sweep generator from 0.5 s to 1 µs/div and another sweep generator from 0.5 µs to 0.01 µs/div.Replace parts of 465 are also easier to find.

author: oldway
author_rank: Super Contributor
timestamp: August 21, 2016, 05:25:19 pm
content: See the prices of Hameg HM 605 on ebay.de :http://www.ebay.de/sch/i.html?_nkw=hm605&_in_kw=1&_ex_kw=&_sacat=0&LH_Complete=1&_udlo=&_udhi=&_samilow=&_samihi=&_sadis=10&_fpos=&LH_SALE_CURRENCY=0&_sop=12&_dmd=1&_ipg=50It is not as expensive as you say !!!!And HM 203 is a lot cheaper.Hameg has manufactured more than 300.000 HM 203...there is much luck to find one at a bargain price...Most of Hameg's scopes have a "Component tester" that Tektronix scopes don't have and which is very usefull to diagnose and repair audio equipment

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 21, 2016, 06:22:47 pm
content: Quote from: rstofer on August 21, 2016, 05:11:11 pmThe transaction's going to take place at my house so plenty of batteries and a lovely Brymen DMM to check them,no problem with that.I'm going to test it before buying.!If the seller brings a function generator (as he said) we're going to test with that too.I'm going to test as much as I can/understand and turn all the knobs.Hope everything turns out okay.Probably need to skim over the manual

author: rstofer
author_rank: Super Contributor
timestamp: August 21, 2016, 07:09:08 pm
content: Quote from: belzrebuth on August 21, 2016, 06:22:47 pmYou couldn't get a better deal than testing the scope at your house. I'll bet it's going to work just fine! The seller wouldn't be so helpful if the unit was junk. It's a heck of a lot more comfortable than sending the money through PayPal to an eBay seller hoping that they ship something that doesn't rattle.Go for it!

author: DimitriP
author_rank: Super Contributor
timestamp: August 21, 2016, 07:43:07 pm
content: QuoteWhat he said.Enjoy your "new" 'scope!.

author: oldway
author_rank: Super Contributor
timestamp: August 21, 2016, 07:54:34 pm
content: Have a look if the fan is in good shape, it is difficult to find a new motor.If it is in good working conditions, I think you will enjoy this oscilloscope.

author: asgard20032
author_rank: Regular Contributor
timestamp: August 21, 2016, 08:11:20 pm
content: Quote from: tggzzz on August 21, 2016, 03:44:17 pmI was jut giving some advise if he decide to go with another analog scope. 475 is fine.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2016, 11:29:08 pm
content: Realise the seller is working in good faith and hoping his trip will not be in vain.If he is willing to bring the scope to you - and a function generator - then I feel there is a distinct possibility he might be happy to give you a quick run-down on operation of the scope - partly so he can 'sell' it as a fully working unit and partly to share an interest that you are showing.It all sounds promising. Let us know how it goes.

author: David Hess
author_rank: Super Contributor
timestamp: August 22, 2016, 01:18:02 am
content: Quote from: belzrebuth on August 21, 2016, 10:17:52 amI think the 465/475/465B have more custom parts than the 2235 but I would not consider that a factor to chose between them because the custom parts are pretty reliable. You have to go back to the 453/454 for something that uses all standard parts and then you will have to deal with a smaller CRT.Servicing can be tricky on the 465/475 and 2235 just because of physical access. The 465M is *another* not 465 like the 465B with a very different physical design which may be easier to service although they look the same on the outside. Still, I would not wait for any of these once one at a reasonable price became available.For what it is worth here are the rough groups these oscilloscopes can be divided into. They all have dual delayed sweep:453 - 50 MHz Discrete453A - 60 MHz Discrete454 - 150 MHz Discrete454A - 150 MHz Discrete455 - 50 MHz Mixed Sweep High Reliability465M - 100 MHz Mixed Sweep Military465B - 100 MHz Alternate Sweep468 - 100 MHz Alternate Sweep Digital StorageThese all have mixed sweep:464 - 100 MHz Slow Analog Storage465 - 100 MHz466 - 100 MHz Fast Analog Storage475 - 200 MHz475A - 250 MHz485 - 350 MHzThe 2-channel 22xx oscilloscopes have several series as well but I am not going to list them other than to say that the 2235 and mentioned 2230 are in the same series.Quote from: tggzzz on August 21, 2016, 04:00:25 pmThe 465 is *not* a 465B (or 465M); they can be consider separate models with the 465B replacing the 465.The 465B and 2235 support alternate sweep instead of mixed sweep on the 475. I have never found a good use for mixed sweep but apparently it is handy for working with analog video. Alternate sweep on the other hand is generally useful. If you have not used alternate and mixed sweep, then I doubt you will miss either.

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 04:16:12 am
content: Quote from: belzrebuth on August 21, 2016, 04:25:08 pmHope you do not lose it by dicking around with these responses and pressuring the seller. The scope has a built-in calibrator that you can hook the probes to. If you can see the signals and the switches are not dirty - buy it. Because you can see it before you buy, with ebay you cannot. I bought and lost out on two analog scopes on advice from this forum (they were both bad).Keep reading everyone's answers and you will lose it.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 09:03:18 am
content: @ez24The price is definitely higher than normal so why not daunt the seller a bit?I agree that the generator is not a necessity but since the seller mentioned he sells one I told him he could bring it along and he agreed.I could end up buying that too although I doubt it if the price is similarly raised,keeping in mind for how much the cheap dds gens are going for on ebay.I don't quite follow you on the forum advice though.In my case I think it's been pretty clear from my posts that I was probably going to go for it but needed some advice on whether this is a really bad deal or an acceptable one.I know it's working but I wasn't so sure it's a solid choice given its raised price.Nobody tried to "convince" me to buy it or not even though nice points have been made for both.You mean that you bought two analog scopes based on advice from this forum and both turned up bad?I don't see how that relates with your final sentence about me "losing it".From your experience I'd expect to tell me to check as much as I can and be really cautious when doing so ,so I won't get a lemon;not being cautious not to pressure the seller.My english is not perfect but I think that you slightly contradict yourself.What would you do in this situation?

author: tautech
author_rank: Super Contributor
timestamp: August 22, 2016, 09:39:42 am
content: It's rarely a mistake to buy one of these IF you have the ability to repair it something goes wrong.If it's a well loved CRO and possibly had some preventative maintenance done on it due to its age It could well be fair value for the money.I've owned a number of CRO's, all of which needed some repair and that gave me a reasonable understanding of their weak points. General recommendation up until recently was to get a CRO as your first scope but affordability was the primary reasoning driving such advice.Those that have learnt scope usage with a CRO are better prepared for future DSO ownership but in saying that a DSO is much more capable but more complex to use to its full potential. For the real novice a DSO is easier to learn with.Reliability is king for the novice, you'd be better to get something new and pursue your hobby without the interruption of a broken scope.The forum is full of threads of newbies with broken CRO's and while we're all willing to help there's not much that can be done as many don't have the understanding or tools to go about many of the more complex or HV repairs.If you think you know what you might be letting yourself in for, go for it and good luck.

author: EEVblog
author_rank: Unknown
timestamp: August 22, 2016, 09:57:22 am
content: Quote from: rstofer on August 21, 2016, 02:01:39 pmAnd that's the trick, without single shot capture available on a digital scope you are missing out on a whole world of signal capture that is invaluable for learning and desiging electronics with.This isn't about paying more for better bandwidth, more memory etc, it's about a hugefundamental differencein tool capability.

author: tggzzz
author_rank: Super Contributor
timestamp: August 22, 2016, 09:59:53 am
content: If you get a working scope at a price that is acceptable to you, then stop agonising over your decision! Buy it, enjoy using it, learn from it, and then -ifyour interests/needs change - you will be in a good position to knowwhythe current equipment is no longer adequate, what youneednext andwhy.IMNSHO, seeing a secondhand scope working is a definite advantage, and is worth money to you. Doubly so if they teach you how to use it! Analogy: it is worth paying extra in a high street shop to see and try on clothing, or listen to the sound quality of a television.It doesn't do any harm to ask them why they are selling it, and whether they know of any problems with it.Unless you need to be able to capture transients, a working 475 is a good scope - especially for signal integrity problems. The few times I've needed to capture transients (PSU startup problems) I've been able to use a very cheap storage scope since the bandwidths are very low.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2016, 11:23:40 am
content: Quote from: tggzzz on August 22, 2016, 09:59:53 amVery much this ^^^^^.While there may be some who cringe at the idea of getting a scope that doesn't feature 'X' or function 'Y', you will learn - and any scope is better than none.From the general feel of the comments given in regards to the 475 that you will be looking at soon, if it is shown to be working, you have a big advantage in the transaction over people purchasing by a photo on the internet. By having personal contact with the seller, you may be able to find out a little about the history of the unit, how well it's been cared for - and, as I said, perhaps have the seller offer you some useful tips on using the scope.There will always be a better scope. Start somewhere.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 02:23:19 pm
content: Bad news guys!The seller got it here but he didn't come up home just unloaded it from his car ,took the money and left!So I'm stuck here with a scope I know that only turns on.It's not in good shape btw..I really think I'm in big trouble here..Can anyone help me confirm the scope is actually ok?I can post pictures if needed

author: tggzzz
author_rank: Super Contributor
timestamp: August 22, 2016, 02:37:08 pm
content: Quote from: belzrebuth on August 22, 2016, 02:23:19 pmOh dear. There's a generic lesson there - have the money inside and get them to demo it before locating the cashAnd be prepared to abort if something unexpected occurs.QuoteWhat do you mean by "not good shape" and "turns on"? Do you see any lights? Can you see anything on the CRT? Centre the time, y position, trigger level controls, auto triggering. Turn up the intensity and press "beam find".There are "how to use a scope" instructions on the web, e.ghttp://www.doctronics.co.uk/scope.htm

author: newbrain
author_rank: Super Contributor
timestamp: August 22, 2016, 03:01:15 pm
content: Quote from: belzrebuth on August 22, 2016, 02:23:19 pmOuch, this does not bode too well, after he promised to even bring a FG...Here you can find the manual:http://w140.com/tekwiki/wiki/475Let's start from the basics:You said it turns on, can I assume you actually tried?Check that the voltage selector on the back is set to the right voltage, even if it turns on.Set the time base to a reasonable value (500µs), the trigger mode to AUTO and the input coupling selectors to GNDAlso, set the Intensity pot to an high value and the vertical mode to ALTCan you see a trace (two actually)?If yes:Goodthere will be more tests, but this a start.If not:Press the BEAM FINDER button, if a trace is displayed, use the Position pots (V and H) to bring it on the screen after releasing the Beam finder.Use the Intensity and Focus pots to have a clear trace of reasonable brightness.If still nothing:That's bad. Something is not working.With a trace on the screen, select an appropriate vertical V/div (100mV), put the coupling selector to DC, and connect one channel to the calibrator:you should see a square wave about 3 divisions high and with a 1 division half-period.If the above goes well, congratulation: you have a working scope (not 100% certain, but very good chances).

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 03:11:46 pm
content: First thing I noticed is that I have to mess a lot with the slope level to get a signal.Here's what I did so far:I connected one probe set to 10x to the calibrator and compensated it in order for the square to be straight.Channel 1 settings are:10mV per DIVAC coupledCH1 button pressedHorizontal display: A lock knobs button pressed.Trig mode : AUTOThe square I get from the calibrator looks squashed at the right end.Controls are crusty ;almost intermittent.And I get this :

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 03:16:52 pm
content: The TIME/DIV knob I'm not so sure it actually aligns with its plastic backside I placed it ten clicks after its left end marked X-Y at .2ms

author: newbrain
author_rank: Super Contributor
timestamp: August 22, 2016, 03:31:11 pm
content: Quote from: belzrebuth on August 22, 2016, 03:16:52 pmThe UNCAL indicator is lighted in your picture. Turn the red "VAR" Time/DIV knob fully clockwise till the "click".

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 03:44:37 pm
content: No matter how I turn the VAR knob the UNCAL light does not turn off.

author: newbrain
author_rank: Super Contributor
timestamp: August 22, 2016, 03:53:33 pm
content: Quote from: belzrebuth on August 22, 2016, 03:44:37 pmThe manual says:QuoteDoes the Timebase change when rotating VAR?

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 03:56:38 pm
content: Quote from: belzrebuth on August 22, 2016, 03:44:37 pmDoes it click? Maybe just a slight force will make it click? There is a slight resistance there.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 04:02:35 pm
content: It doesn't turn a full circle like the VAR knob on the VOLTS/DIV it does just clicks from one point to the other.It clicks in place but I don't see much difference.I'm starting to think that I have to call back the seller.I'm really a noob but I don't think that's a fully working scope.Can anyone tell me what I need to do to confirm that the scope is fine or not?Knob settings maybe?I can take photos of the scope with the recommended settings so we can verify what the scope shows accordingly.

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 04:17:17 pm
content: After you return it, you really need to buy a new one. I do not think an used scope will fit your needs.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 04:28:36 pm
content: I think I agree on the new one.But I'd really like to test it before returning if possible.I may be a complete fool right now and the scope could be fine.We can never know if we don't verify that the scope is faulty.

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 04:38:05 pm
content: Quote from: belzrebuth on August 22, 2016, 04:28:36 pmSince I know Tek and not you - I agree with bothYou do have the manual? Go through the Basic Oscilloscope Displays section

author: tggzzz
author_rank: Super Contributor
timestamp: August 22, 2016, 05:00:36 pm
content: Quote from: belzrebuth on August 22, 2016, 03:11:46 pmClearly the scope is not completely faulty.I suggest you take a deep breath, turn the scope off, find the scope's manual, and read the "operating information" section to find what controls are where.In it you will find a subsection "obtaining basic displays". Connect a probe to the cal input, and follow the examples in the "obtaining basic displays" section. Note that modern DSOs are typically worse at this point, since many controls are invisible and are hidden in a menu structure. OTOH, they often have a "display something" button!

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 05:13:06 pm
content: I think the VAR knob in the TIME/DIV knob is permanently pushed down (broken in probably).I cannot see the screw on the red knob whereas I can see the screws of the other VAR knobs on VOLTS/DIV.I can't also turn the var knob a full circle.

author: tggzzz
author_rank: Super Contributor
timestamp: August 22, 2016, 05:21:52 pm
content: Quote from: belzrebuth on August 22, 2016, 05:13:06 pmYou should be able to see the grub screw.Including clicking into the calibrated position, it should rotate just over 270 degrees (not 360 degrees).

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 05:46:06 pm
content: I think I'll try to find the seller and convince him to take it back..

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 05:51:36 pm
content: Quotegood - probably done at the factory, in other words it does not push down or upQuotenot good, it is small, look againQuotegood - especially if no set screw and since you can make it click - look again for the set screw

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 06:16:56 pm
content: It doesn't rotate more than 30 degrees or so.It's probably broken somehow.I didn't expect it to push down or up but the knob doesn't rotate and I can't see a screw like on the other var knobs.

author: oldway
author_rank: Super Contributor
timestamp: August 22, 2016, 06:24:46 pm
content: You need help from somebody who can test the scope for you.I see there is a repair café in :Anakiklono stin Pigi - I Recycle at SourceKaraiskaki st. 120RioPatras265 04GreeceIs it far from your home ?Perhaps they can help you.http://repaircafe.org/en/locations/repair-cafe-patras/

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 06:43:32 pm
content: Thank you very much for caring oldway.That spot is not close (4 hours drive give or take) but if I have to I may try my luck there.Problem is that people who can fix oscilloscopes are rare ..The seller does not answer my calls so I fear that I may have to keep it..

author: oldway
author_rank: Super Contributor
timestamp: August 22, 2016, 06:52:44 pm
content: Do not panic ......It seems that most of the functions are working, you can use it as it is.

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 07:20:09 pm
content: Quote from: belzrebuth on August 22, 2016, 06:43:32 pmQuoteBecause it would cost 20x the price of the scope, so no one pays for this.You can use the calibrator to see how far off it is and just remember it. I think by the time this matters (precise timing calculations) you will have moved on to another scope anyway. Don't sweat it. What drives me nuts are dirty switches because you see that every time.Once you are sure about the switch then start a new topic with a title like "Tek 465 red VAR Time/Div knob turns only 30 degrees"What is funny - someone said 270 and you say 30 . I wonder if you are on the other side of the swing? I wonder what could be wrong? If you do start a new topic, please say so here so I can look out for it. I am curious now. Who knows someone may have a fix.For more help, Yahoo has a Tek user group that I hear is good for this kinda thing. I think most of this forum has moved on to digital scopes.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 08:25:49 pm
content: ez24 thanks for the tips but the seller finally picked up the phone (called from my brother's phone) and said he could come and take it back!I hope he's honest enough to do that.If it was 50-70€ I'd keep it and try to fix it but it's 150 and it's not behaving properly so I'll give it back.Its main problem besides the always on UNCAL light is that with no probes after turning the TIME/DIV knob from the seconds range to ms ? see no traces running until I push the auto trigger button momentarily.Then the trace runs once and disappears.Sometimes it doesn't do anything.I watched a few YT videos and the scope should have one or two traces (if the alt or chop button is pressed) running horizontally with no probes connected.I believe the stuck VAR knob has something to do with that because the problem is intermittent and the scope behaves differently when I wiggle the knob.I'm not really sure what I'm doing regarding oscilloscopes but I don't think that's a great way to start.I'd love to have gotten a working scope to experiment and learn but troubleshooting something so complex right from the start is not nice.

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 08:30:35 pm
content: You are lucky this was not an ebay scope because shipping would have killed you no matter what happened.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 08:54:01 pm
content: Did you actually fix your eBay scopes?You didn't go into details on what happened..Perhaps outside the scope (pun) of this thread though..

author: David Hess
author_rank: Super Contributor
timestamp: August 22, 2016, 09:10:37 pm
content: Quote from: belzrebuth on August 22, 2016, 08:25:49 pmI agree; that is too much for a broken 475 unless you have the facilities to repair it and plan on repairing it before the sale.I bought a pair of 2230s off of Ebay for less than $100 each *knowing* that I would likely be diagnosing and repairing them. The first one worked but suffered from popcorn noise on one channel which took weeks to track down and repair. The other worked fine. I still use both.QuoteI suspect someone already attempted repairs and put it back together incorrectly which is pretty easy to do with the dual timebase controls. It is possible that the current seller does not know anything about oscilloscopes so could not tell that it is not working correctly.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 22, 2016, 10:37:47 pm
content: Quote from: David Hess on August 22, 2016, 09:10:37 pmCurrent seller must indeed know nothing about scopes.He acted very surprised when we talked on the phone.He was like "Hmm,it must be really a simple fix because the scope is in excellent working condition but if it doesn't suit you and you need to return it that's fine with me"I don't see how anyone could own a broken oscilloscope for as long as he stated he had and even try to sell it (for that much) without actually testing it.!It's test equipment so most people are going to use it as such;even a noob like me could actually tell something's not rightAnyways,I hope he honors what've talked about and come to take back his doorstop.I feel sad for this scope but I think I have to be more careful from now on.I'll update when this is resolved.

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 10:40:40 pm
content: Quote from: belzrebuth on August 22, 2016, 10:37:47 pmSounds like an ebay seller

author: Brumby
author_rank: Unknown
timestamp: August 23, 2016, 12:45:18 am
content: Quote from: tggzzz on August 22, 2016, 02:37:08 pmYes. This is Rule #1.If the seller tries to coax the money out of you too quickly, just be polite - and firm - saying you just want to confirm it is working as expected first. If you get grief at such a suggestion, then this is a warning sign.Taking the money and leaving is not encouraging, but there could be valid reasons for his haste.The true test will be that he:1.Doesturn up to take the scopeand2. Offers you ALL the money you paid. Some might claim a 'restocking fee' or 'travel cost' - but don't let him get away with anything but refunding you the full amount.If he wants to know why - just tell him the issues you found.He might want to check them out - but if he starts getting into a discussion about them and starts trying to convince you that it's OK, then just DON'T take the bait and stand your ground for the refund. You are not familiar enough with the unit to make an informed decision.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 23, 2016, 02:07:19 pm
content: I toyed a bit with the trigger function again today and I never got the scope to display a free running dot without me pushing and unpushing the AUTO button each rime.I don't think I have to press an "AUTO" button manually each time for the scope to display its free running dot.I believe that besides the stuck VAR knob inside the TIME/DIV switch there might have been a triggering issue all along.Who knows?Good news though!The seller came and picked it up this morning.I told him to come up this time for a coffe and tried to explain him what's probably wrong with his scope.He was staring at the screen while randomly pushing buttons and knobs like it's going to fix itself somehow..He was indeed clueless.I was refunded the money so no problems there.There are two options for me now as I see it.Either get a much cheaper analog one (max 50-70€) and try my luck (again) or just save for a Rigol 1054z which gets nice reviews all over the net and should be a decent choice for a beginner.Maybe I should just leave the first option to pure luck and start saving for that Rigol.

author: newbrain
author_rank: Super Contributor
timestamp: August 23, 2016, 03:03:19 pm
content: Quote from: belzrebuth on August 23, 2016, 02:07:19 pmGood to hear!He was probably in good faith, then.QuoteYou were lucky once after all, do not tease the blindfolded goddess...Given the level of your scope experience, I would start saving and get a new, guaranteed working, and modern scope.The 1054Z is still a very good options, though you can see a lot of discussions on this forum (test gear section) on its shortcomings and defects, with some of them heating up quite a bit.The amount of discussions on this specific scope is probably due to the sheer number of persons who ended up getting one.I own one too (hobby, not work) and it's definitely good enough for my usage, especially in its "enhanced" form.Others options exist, though, do not discard them immediately (you've got time make your mind up).

author: tggzzz
author_rank: Super Contributor
timestamp: August 23, 2016, 03:49:03 pm
content: Quote from: belzrebuth on August 23, 2016, 02:07:19 pmThat's a standard dilemma; you are damned if you do and damned if you don't.Are there any local clubs/societies where you could either learn how to use their equipment and/or pick up contacts about who is selling what? Radio amateur societies and hackspaces/makerspaces are the obvious starting point.Don't forget you can do a lot of electronics without a scope, provided you have imagination and understanding. I designed and built a TTL 6800 computer using only switches LEDs and a multimeter.Most importantly, your judgement that the seller was trustworthy has proven to be correct.

author: David Hess
author_rank: Super Contributor
timestamp: August 23, 2016, 04:44:14 pm
content: Or keep a eye out for a local deal while saving for a new but low end DSO.

author: oldway
author_rank: Super Contributor
timestamp: August 23, 2016, 04:59:35 pm
content: May be it is time to think about your wrong choice and to change of behaviour.You will find on this forum a lot of people who are never satisfied with nothing and you do the same thing.You need a 20 Mhz oscilloscope and you will buy a 200 Mhz...You need a single time base oscilloscope and you will buy one with delay time base and TWO mains time bases....You probably think that a sophisticated instrument will compensate your lack of knowledge and experience in electronics, but it will not do this.Read again all the posts of this topic and you will remember that there are very simple and cheap analog oscilloscopes that fit your needs as HAMEG HM203 or HM204They are reliable, simple to use and easy to repair if necessary.The cheap digital oscilloscopes are rubbish with a lot of problems as aliasing for example.Don't buy thoses pieces of shit...If you buy a digital scope, buy a good one !

author: DAIRVINE
author_rank: Contributor
timestamp: August 23, 2016, 07:01:08 pm
content: "The cheap digital oscilloscopes are rubbish with a lot of problems as aliasing for example."That is correct. However if you just want a scope so you can experiment and see a few simple signals on electronics kits a new cheap digital scope will probably be adequate. Some cheap digital scopes based on cypress chips have a very long buffer because the buffer is PC memory. This very long buffer might sometimes be useful to professionals. For example you can get an IR receiver and look at the signals. If you are serious about electronics then get a decent digital scope. Old analogue scopes are probably best left to collectors and those who know why they need one and know how to fix it. Avoid very old digital scopes.Read reviews on anything you think of buying.A similar comment applies to TV Dongle spectrum analysers(RTL SDR, eg NESDR SMART). They have rubbish specifications. But are a tiny fraction of the cost of anything better. And for some things they are really quite good. But they can mislead you.

author: oldway
author_rank: Super Contributor
timestamp: August 23, 2016, 07:14:23 pm
content: You should remember what belzrebuth wrote:« Reply #4 on: August 21, 2016, 11:55:43 PM »QuoteHe never intended to buy a digital oscilloscope now.To buy a low end digital scope now would the worst choice he can make.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 23, 2016, 08:41:34 pm
content: I'll just keep an eye for an analog one ;one that I can properly test before buying or a very cheap one that I can afford to spent time on trying to repair if anything goes wrong.Cheap stuff even slightly malfunctioning you rarely regret getting ;and probably have a lot more courage and patience fixing it.I slowly got into electronics in order to fix or modify things on my own and I've actually repaired a lot of stuff (synths,old samplers,floppy drives,mixers etc) over the past 2-3 years with just a soldering iron,patience and a multimeter but as time goes by I feel that not having an oscilloscope is holding me back from troubleshooting more advanced problems and acquire a better understanding of how things work (or why not)It's the next logical step..I never said that I need a higher end instrument ;I just found a 475 and thought why not.I wouldn't mind if it was a Hameg or something else..I would be perfectly content with a 20mHz scope if it happened to pop up locally..A digital scope is surely a much more expensive choice that will become obsolete and lose its value over time ; I don't very much like their LCD screens for seeing waveforms and they seem flimsier than the analog beasts of the past that's why an older Tek still appeals to me as a first scope.I think this little adventure shouldn't discourage me from keeping an eye open for one;I'll be getting a DSO when I'm ready to do so financially and when I've hopefully gained a little experience in order to choose wisely what to get.Till then I'd very much like to start messing with a nicely working analog one (if I manage to get one) and learn the basics there.

author: tggzzz
author_rank: Super Contributor
timestamp: August 23, 2016, 09:01:39 pm
content: That's all very rational. For audio, a 10MHz scope is adequate, as I'm sure you realise.Around here my rule of thumb is to try to get one for £2/MHz plus shipping. The local hackspace is occasionally offered low end scopes free, because people can't be bothered to sell them.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 24, 2016, 01:07:36 am
content: Quote from: belzrebuth on August 23, 2016, 08:41:34 pmThis will sound strange,coming from an old analog Greybeard like myself,but such DSOs as the DS1054Z & similar ones will still be able to do the same stuff in10-20years that they can do now,providing they don't break down.They may become "obsolete" in some applications,but will be OK for many others.The two types of DSOs I would stay away from,are very old ones,& very cheap ones.Analog Oscilloscopes are still useful for much general work,& you can do a lot of stuff with quite basic instruments.Here is a quote from my comments on another thread:-"On the other hand,although this thing* looks like it was designed to be operated by "Cabbage Patch Dolls",it is a real,usable test instrument,after you get past BNC connectors that become unscrewed,& knobs that fall off."*http://www.eham.net/data/classifieds/images/364574.jpg

author: Brumby
author_rank: Unknown
timestamp: August 24, 2016, 04:41:07 am
content: Quote from: vk6zgo on August 24, 2016, 01:07:36 amThis is something that many people don't appreciate.I still have an old 486 computer running Windows 3.11. It doesn't get used for anything these days, but it still runs ... and once I get (an ancient version of) Word up and running - I still can't type faster than it can handle.

author: oldway
author_rank: Super Contributor
timestamp: August 24, 2016, 08:49:25 am
content: I follow closely the used analog oscilloscopes market in Europe because many friends ask me for help to buy one.There are about ten years ago, there was a large amount of analog scopes for sale and you could do very good deal.At the time, large companies were getting rid of their analog scopes to switch to digital.Those days are gone.Now the analog oscilloscopes are rare, and even a simple analog oscilloscope 20 Mhz quickly reached 100 € if it is in perfect working order.We can still do good deal with non working oscilloscopes or for parts, but you have to know how to repair it and must find replacement parts.Buying a non working analog oscilloscope remains a game and you have to be lucky

author: Zbig
author_rank: Frequent Contributor
timestamp: August 24, 2016, 09:16:25 am
content: belzrebuth, you've said you like CRTs and don't like LCDs while admitting you've never really used a scope of any kind before. Are you sure that your preference for analog scope isn't a result of some hipstery desire of using something "vintage"?Bear in mind that many of the guys here reinforcing your decision to get an old analogue scope probably have long experience in the field and analog was the only thing available throughout most part of their careers. That's the way they were doing things and they will come up with all sorts of justifications why analog is the way to go. That's life, that's how many people's minds work. In my opinion, there is absolutely no reason for starting with analog in this day and age. Would you buy a CRT TV now? Sure, if you're lucky to get an analogue scope that actually works and will meet 90% of your needs for debugging synthesizers, there will be a moment when you'll need to diagnose an intermittent, one-off timing issue that happens only on power up. Then, the novelty of feeling like an "electronics wizard" long worn off, you'll find yourself sitting in front of your old, crusty, heavy piece of antiquated garbage taking half of your workspace, feeling like a fool. I like steampunk as much as the next guy but do yourself a favor and save for a proper modern (EDIT: digital) scope from current century. If it's hard for you to justify the higher upfront cost, think of it as buying not one but two instruments in one (taking 1/10th the space, weighing 1/10th of the analogue one, etc.). Yes, as Dave already pointed it out for you, the ability to catch one-off events does make a world's difference.

author: David Hess
author_rank: Super Contributor
timestamp: August 24, 2016, 12:11:46 pm
content: Quote from: Zbig on August 24, 2016, 09:16:25 amMy justifications for using a Tektronix 2230/2232 instead of something more modern come down to:- Higher CRT resolution even in DSO mode than most modern DSOs.- Documented and understandable operation making surprises rare.- Good user interface.- Cheaper by an order of magnitude than an acceptable modern DSO.But I would never buy an old or new DSO which does not support peak detection which immediately disqualifies a lot of currently made inexpensive DSOs. I would also never buy a DSO which does measurement processing on the display record which disqualifies the Rigol 1000Z series and I assume most of their other DSOs; that is just cheap engineering and it shows in the other problems their DSOs have. Other uses may find these problems acceptable but since I have old DSOs which do not suffer from them, I do not.QuoteThe coat has to be cut to fit the cloth. At least here in the US, good used analog oscilloscopes can be found for $100 or less so if it is a choice of buying something for 1/10th the price now which will do 90% of what is needed, that may be worthwhile. Overseas this decision is more difficult because good used analog oscilloscopes are less common and more expensive.

author: oldway
author_rank: Super Contributor
timestamp: August 24, 2016, 12:45:33 pm
content: I really don't know what advantage has the 2230/2232 over the 2235?It is far more complicated with an big digital board added without any true vantage for a beginner.I had a 2230 when I worked as maintenance engineer in high power UPS and it was usefull to measure transfer time between inverter and mains when we shut down the inverter.We buy an HAMEG 1507 (combiscope) to do the same but it was a desaster. Every time we make a transfer, the oscilloscope stopped responding without any control anymore.I worked also in the biggest european manufacture of SMPS.We had a lot of Philips/Fluke combiscopes.I made an inquiry with my colleagues : virtually all of them never use the combiscope in digital mode.I wonder what the digital fonction of 2230 you use for ?In repair, analog and power electronics, I really never need this.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 24, 2016, 01:38:56 pm
content: Quote from: Zbig on August 24, 2016, 09:16:25 amI don't have such a hipstery desire but I like the CRT traces ;their resolution seem crisper than the cheaper DSOs and their screens are very bright and nicer than the plain boring lcds you look everywhere.Call me a hipster if you like for wanting to use stuff that also look good to me but that's just the way I see it.Also the price is a valid reason too.For example when I started soldering stuff I got an plain weller soldering iron that plugs into the mains.I didn't get a brand new digital station or a "vintage" analog station from ebay.Just a quality plain soldering iron to learn with.Three or four years later I just got a low end fx-888d although I'd prefer a fx-888 without the digital up and down buttons but I wouldn't get a vintage weller station or similar.I'm ok with modern functionality but I also like the hands-on control and lower prices of the analog scopes.A lot of people are into analog stuff for this reason (hands-on control,simpler operation/less features== easier to grasp,almost one knob per function etc.)

author: Zbig
author_rank: Frequent Contributor
timestamp: August 24, 2016, 02:07:25 pm
content: I believe I still have this baby:https://www.google.pl/search?q=unitra+os-352&source=lnms&tbm=ischat my parents'. Would part with it for just the price of shipping. Interested?

author: oldway
author_rank: Super Contributor
timestamp: August 24, 2016, 03:28:25 pm
content: Quote from: Zbig on August 24, 2016, 02:07:25 pmNow I understand why you don't like analog oscilloscopes.....Try one of those and you will change your mind....

author: Zbig
author_rank: Frequent Contributor
timestamp: August 24, 2016, 03:51:36 pm
content: Quote from: oldway on August 24, 2016, 03:28:25 pmNope... But it's a nice musesum display you've got youself there. You just might want to prop up the shelf with something if you're going to keep them comingAnyway, as the original poster seems to have his mind set, I'll just grab someand come back to enjoy next episodes:scratchy potentiometersdodgy rotary selectorsstuck switchesrodent infestationsBut first, I'll hop into my horseless carriage and take the journey home.

author: newbrain
author_rank: Super Contributor
timestamp: August 24, 2016, 03:55:31 pm
content: Quote from: Zbig on August 24, 2016, 02:07:25 pmI think myold scopetrumps yoursAt my parents, still working, still ~30kg for ~30kHz. My Rigol should weigh 100tons.

author: Zbig
author_rank: Frequent Contributor
timestamp: August 24, 2016, 04:16:51 pm
content: Quote from: newbrain on August 24, 2016, 03:55:31 pm30kHz you say? So you shouldn't ever need anything better for your audio work!

author: oldway
author_rank: Super Contributor
timestamp: August 24, 2016, 04:27:56 pm
content: QuoteA good contact cleaner spray cost less than 10€.With digital scopes, you have more serious problems as faulty encoders (very fragile), faulty touch buttons (very common)....

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: August 24, 2016, 04:33:44 pm
content: @ belzrebuthIf you are looking for a 20 Mhz analog scope, you may possibly get it for free.Try asking some university lab if there are some in your area.I recover several of these in the trash, which I could bring back to life with moderate effort.Some good options are the Fluke/Philips PM3209, PM3335 series. Fairly well documented, with a bigadvantage over many other old or modern scopes :- They do not have fan. So you are in total silence.(and much less massive than a Tek 475 (I have a Tek 468 which is similar but its a monster compared toa PM3335 or to the Rigol 1054Z that I use most often)).Other good options as was said is the Hamegs 203 or similar.Just wait for a good opportunity (but be active to make it happen) and maybe you will get one for free.

author: chris_leyson
author_rank: Super Contributor
timestamp: August 24, 2016, 04:38:17 pm
content: I've owned a 465 and two 475s over the years and to be brutally honest I wouldn't touch them with a barge pole given their age, probably around 30 years old now. Switches, pots tiny spring contatcts on PCBs, semiconductors, I've had issues with all of them. They can be difficult to repair even with a service manual and then you might need a donor scope just for spares. If you really need an old analog scope look out for a 50MHz or 100MHz scope maybe Hameg or IsoTech, pretty sure you can pick these up for 50€ or so.

author: newbrain
author_rank: Super Contributor
timestamp: August 24, 2016, 05:34:46 pm
content: Quote from: Zbig on August 24, 2016, 04:16:51 pmWell, my younger self used it quite a lot for audio.The best use was for my Electronics 1 test at the university.Sorry for the OT...I was sure I had made a perfect test, and once home I had actually built the circuit in the test assignment.When I went to check the date of the oral test and the written test results I was shocked: 10 out 30.I then took pictures of the scope and the circuit (a simple CC generator charging a capacitor!) with mysmartphonefilm camera, had them developed and brought them at the oral test.It was quite a struggle (the professor would not admit in public he was dead wrong), but the evidence was out of question.My fault? I had added also the calculations and extended the graph to include the behaviour when the transistor in the CC source saturated (i.e. no longer CC).In the end he gave up and stated many of the tests had to be re-evaluated.My final result? 25/30...He said "OK, you know electronics, so let's start with Schrödinger's equations"

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 24, 2016, 06:29:00 pm
content: Sadly public universities in my country usually give their old/broken equipment to recycling companies.Sometime ago I needed a bunch of floppy drives for something I was working on so I went to my university and asked if they happen to have any in storage.A friendly guy working there told me to follow him and searched in the storage room while I was outside waiting.I asked if I could come inside and help him but he didn't let me to go in and search myself.He grabbed a couple of drives and gave them to me.I peaked inside this room and he probably had a closet full of drives including ribbons etc so I asked if I could have some more floppies since they're super obsolete and pretty useless for almost anyone these days.He said I couldn't and that he's already doing me a favor cause they give these things away to other companies (recycling).It's state property since it's a public university so they can't just sell or give away stuff.So if they have such policy for even a bunch of useless floppy drives imagine me going there asking if they happen to have a spare Tek scope..I should probably try my luck in other universities too..

author: David Hess
author_rank: Super Contributor
timestamp: August 24, 2016, 08:27:24 pm
content: Quote from: oldway on August 24, 2016, 12:45:33 pmDo you mean other that selectable digital storage with pretrigger capability? People here often point out how useful these features are and their lack in an analog oscilloscope.I was using these CRT DSOs as an example of why CRT displays can look as good if not better than LCD displays. I would not necessarily recommend a 2230/2232 to a beginner because of their increased cost and complexity but with the exception of the 2210/2211, they are the oldest DSOs that I would recommend to anybody.QuoteI use it for the typical applications which would require a digital storage oscilloscope like capturing single shot or low repetition rate signals or where a pretrigger is needed. Another very handy feature is the reference memories which allow comparisons with previous waveforms. Glitch detection in digital mode highlights pulses which may otherwise be difficult to find in analog mode. Cursors allow accurate on screen measurements. The readout in analog and digital mode helps with documentation.A modern cheap DSO will do most of these things as well but at several times the cost so there is little reason for me to upgrade.

author: oldway
author_rank: Super Contributor
timestamp: August 25, 2016, 11:23:44 am
content: Capturing single shot or low repetition rate signals is something you really don't need often.Most of signals are repetitive (periodics) and they are perfectly captured by an analog oscilloscope.Of course, when you have the same level of expertise as Dave and you make a debugging of data signals to hack a R§S dso (see EEVblog #879 - R&S 1202 Scope Bandwidth Hack Investigation ), you need the single shot, storage and pretrigger options of a DSOBut we are speaking about an oscilloscope for a beginner.Some exemples where DSO is not absolutely needed:- to measure overshoot on power-on of a power supply: no need of an oscilloscope, use your multimeter in peak max capture.- to measure dynamic behaviour of a power supply: you may use a low frequency repetitive rate and the pattern is readable with an analog scope.To measure peaks, use the X/Y function with no X input signal.- PID regulator caracteristics: same as above.- filter caracteristics using sweep generator: same as above.When X/Y function is needed , analog oscilloscope is better than DSO.The reference memories which allow comparisons with previous waveforms is usefull when you work on the production line of a manufacture, but for sure, is useless for a beginner.Glitch detection is also possible without DSO mode.For exemple, Hameg oscilloscopes have a very fast overscan detection who let you detect glitches even you don't see.Cursors allow accurate on screen measurements, I agree, but what accuracy do you really need for such measurements ?There are pure analog oscilloscope who have also cursors.Readout is not necessary and even can be switched off because it can interfere with display of the signal.EDIT: about pretrigger, all modern analog oscilloscope has a kind of pretrigger: a delay line that serves to visualize the leading edge of the wave.