Oscilloscope for non electronic use

[Error_code]

Oh yea, the title says it all.

I'm looking to find some old analog Oscilloscope mainly for decoration.   

I know it sounds silly and weird..  but i find those weird oscilloscope kinda facinating, especially when they read sound wave.

I have a workshop  (actually its my garage) where i mainly do woodworking...  I have a senior college degree in computer science + 20 years experience.
My second degree is education.

I went on craiglist but somehow i find it difficult to dig the right Oscilloscope...

All the terminologies, Heathkit, Generator, Calibrator, 20mhz, 50mhz, 60mhz...  they really mean nothing to me.

My knowledge of electronic stops at reading my house current using my Fluke multimeter.

Back when i was a kid (30years ago), i took some basic electronic courses ie: Resistance, capacitance, AC/DC,  but when you don't work with something you pretty much forget everything.
So this is pretty much where i'm coming from, where i am and where i want to go.

One thing i want to do with a scope is to display sound waves for now...  but later my son will probably want to learn the scope beyond that. So the scope has to be fully working and i presume "calibrated?".

The other thing i need to know is how exactly you guy wire the probes to read the live music from speakers.  For that i will need pictures as i don't want to blow my audiophile equipment...  my wife wouldn't approve that

Oh by the way, i 've been following EEVblog for more than a year without posting...  this is my first post.

[AndyC_772]

Lol That's the first time I've heard of anyone wanting a piece of lab equipment purely for decoration, but it makes your choice a whole lot easier than it might be otherwise. Normally I'd advise people on equipment based on bandwidth, memory depth, number of channels and such, but in your case I suggest having a look on Ebay for any scope you like the look of. The spec really doesn't matter, any scope will show an audio signal.

You need a scope that works, of course, but it certainly doesn't need to be calibrated. If you'll have it plugged into your hi-fi, you'll probably want to check that the cooling fan is quiet; many scopes are rather noisy for a domestic setting, especially if it's getting on a bit and the fan bearings are be on the way out. They can also be quite power hungry; my scope does quite a good job of keeping my lab warm, I don't need the central heating on in there when it's switched on.

If you have a tape loop on your amplifier, that's probably the easiest way to connect it to your scope. Just run a cable from the record output into the scope, probably via a phono-BNC adapter. If you have a 2 channel (or more) scope, you can show both left & right channels simultaneously - otherwise just pick one channel, they'll both look much the same anyway.

[TerraHertz]

If you just want a 'technical looking' thing that displays a pretty screen from audio, then definitely get an analog scope. The Tektronix 7000 series look cool. Maybe a 7603 with cheap plugins? There should be plenty of these around still. Being able to easily slide the plugins out so you & friends can admire the internals is a plus too.

If you get a scope that has X-Y mode, you can connect your two stereo channels to the two inputs, and get some nice looking 'squiggly' patterns on the screen.

[PaulAm]

Depends on what you want to spend.

Everything below is about analog scopes, I'm skipping DSOs since that is a nuclear bomb equivalent for your application.

Tek 7000 series are lab quality scopes and you'll still spend over $100 for a working one with plugins.  Kind of large, too.

The Tek 500 series are iconic.  They were all vacuum tube, but you still see them show up in background shots in movies and commercials when the ad guys want to look scientific.  Big and heavy though.

Eico/Heath made basic scopes, you can find them for $25-50.

Leader made a lot of scopes (and still does today).  You can find older analog versions in the 50-100 range.

You actually have a good application for a PC based scope.  Get one of those USB adapters and you can turn an old laptop into a multichannel scope.  Not as cool and iconic though

[Error_code]

Thnx guys  for the input.


Right now i have to choose between the following models:

Oscilloscope Hitachi V1065 A  with 2 probes.  the guys is asking $300

Oscilloscope Kikusui COS5060A with 1 probe  the guy is asking $200

Oscilloscope HeathKit IO-4235, Dual 35 Mhz /w Calibrator IG-4505 and printed manuals  Not sure about probe, and he's asking $100

What do you guys think ? 

By the way,  my ipod touch does have some oscilloscope apps installed..  are ipod oscilloscope demo/apps  accurate ?

[Psi]

At audio frequencies the probes don't matter, and you're not going to be probing circuits anyway.
You can wire up any BNC cables you have laying around to some RCA leads and it will work fine for displaying an audio signal.
If it does come with probes though, you could cut them off and use the cables.

Ideally you want a dual channel scope so you can have the left and right audio channels displayed on the screen together.

[c4757p]

You have to choose between a $300 scope, a $200 scope, and a $100 scope just for decoration? I'd choose to wait. I got my first analog scope for $50 and it was fully functional and in calibration on all modes and settings. All you need is a working trace and trigger and you're set.

The guy asking $200 for a 60MHz two-channel Kikusui with no features beyond "shows traces" is on crack. That or he naively bought it for that much, saw what they really sell for and hopes some other sucker will get him his money back. The thing is pretty much one bandwidth step above my $50 one and in every other way equal. The Hitachi is pretty nice but massive overkill.

Just be patient. Wait until a cheaper one comes your way.

[Error_code]

The guy selling that Hitachi V1065A  is negotiable..  he says that the included two probes are 100mhz

Not sure what that means.. 

When you mean overkill, i presume you mean that it is a Pro grade scope meant for real electronic work way beyond my needs ?

Does this scope even work on 120AC  or does it require 240 V ?   because the only 240 outlet in the house is behind my kitchen  stove

[c4757p]

The probes, just like the scope, have a bandwidth of 100 MHz. That means that you can probe signals up to that before they end up attenuated by 3 dB. This is many times greater than anything you'll be probing - audio doesn't even approach 100 kHz, let alone 100 MHz.

Yes, it is (was) meant for "real" electronics work back in its day - it would still be respectable today, at least in a home lab. No reason to pay that much for a decoration. I have a 150 MHz Tektronix that is pretty similar to it and I use it for everyday work in preference to my crappy annoying Rigol...

I'd check the voltage compatibility but I'm pretty sure I won't be able to tell from the model. They usually either have a switch on the back, or they're made in two voltage versions. Being a reputable brand my bet is on the switch.

[PaulAm]

What you should look for is a Tek 5103.  These were fairly low bandwidth scopes, but they have large screens and the ability to add plugins, some of which are pretty sophisticated.  You can get one plugin that turns it into a semiconductor curve tracer, for example.  The CRT circuits are pretty simple and, if something goes wrong in the vertical or horizontal sections, you just get another plugin (which I have bought at hamfests for as little as $5).  There are a number on ebay now for $100 or less including shipping.  If you look around, you can generally find them for less than $100 with a full set of plugins - you want 2 vertical amps (one for each channel) and a timebase.

Not too long ago, I picked up a 5440 with a half dozen plugins, including the curve tracer and a cart, for $100.  Actually, I bought it for the curve tracer plugin, the rest was a bonus.

If you're primarily interested in art, I wouldn't pay $300 for the Hitachi.  It's not a bad scope, but that seems a little steep for a 100 MHz scope, even if it does have cursors.  If you were going to pay $300 for a scope to do real work, I'd recommend Tektronix since parts and service docs are readily available.  I also admit to bias on that point.  I had a Tek 2465 on my local Craigslist for $180 this week.

[funk1980]

If it's soundwaves you want to display for decorative purposes, just get any cool looking analog (CRT), two channel scope. 20MHz bandwidth is more then plenty (sound only goes to 20kHz and higher bandwidth ones tend to be more expensive). Connect a simple cheap electret microphone to one of the inputs, set to a small amount of volts/div and enjoy!

[TerraHertz]

Speaking of decorative purposes, here's a kpop video with an oscilloscope and some other bit of gear.
     4Minute - 'WHY'

Too bad they are pretending to use the scope, despite it not being turned on!

What is the thing in the suitcase? Some sort of emulator? At least it's powered up.

Edit: Darn it! Is there any way to post a youtube link without inserting a still image in the post?

[nixxon]

If it's soundwaves you want to display for decorative purposes, just get any cool looking analog (CRT), two channel scope. 20MHz bandwidth is more then plenty (sound only goes to 20kHz and higher bandwidth ones tend to be more expensive). Connect a simple cheap electret microphone to one of the inputs, set to a small amount of volts/div and enjoy!

I agree. A 15 MHz Tektronix 422 is a silent (no fan), compact and neat looking scope. And inside it is really clean, as the case has no openings. Pretty old, though (40-45 years).

[Error_code]

I'm updating craiglist and other sites every day.  But most scopes in my area cost 150+ .  I guess i need to wait a little longer.

I'm not a big fan of Ebay.... know what i mean.

Back when i was a kid (30+ yrs ago), my parent bought me one of those Radioshack Electronic kits with colored wired (jumpers) and springs.  Those kits allow you to make electronic stuff, lighting effect LED and sound.   I was  like 7 or 8yrs old kid trying to learn electronic but it was way above my skill to read the circuitry.  Anyway, back then i gave up learning electronic and focused on Computer science.
I did computer science also because jobs were easier to find.  But that didn't mean that i was no interested in electronic.  I always liked electronics.. i enjoy looking at boards and component quality. I find it very interesting.

The last electronic device i have repaired by my self is my LCD monitor, (blown capacitors).   That was fairly easy to diagnosis ( google ) and easy to replace. Although i didn't know what the numbers meant, i just replaced the 3 capacitors with the same part number.  Saved myself atleast $100. 

But i know that electronic in real life is much more complicated than changing capacitors...  not to mention the engineering level.

So maybe one day, i'll give another shot and maybe try to understand better how electronic works and hopefully repair more complex stuff.

For that i may consider a good hobbyist scope. A  scope that i can easily recalibrate . Something i can pass to my son too   

By the way, should i buy a Signal generator or a variable power supply ?  and is there anything easy and i mean very easy to do with a scope something that is useful for home repair ?

I.E:  i use my volt-multimeter to check the house outlets and car battery. I know what to do with my multimeter.  But if i get a scope, i might need to justify to my wife and to myself that a scope can do something useful to the house/car or something. I don't think she will be happy to see me spend our money to buy a device she may find ugly for a sole special effect purpose.

I was wondering if you guys could list or point me out few things i can do with scope without the needs to learn electronic basic.

And things i should never do with a scope: If i put the probes on (say)  a car battery would i blow up the scope.






Because i tend to l

[PA4TIM]

Do not buy a scope, it has no use in automotive ( other then for very specialised things, and if you did those thing you would know why you needed a scope for it)
And measuring wall outlets is besides useless also very dangerous. And not just because mains are dangerous but because you need extra things for that that do not come with the scope ( unless you are talking about a scope-meter that is batterypowered and floating with differential inputs so you do not electrocute yourself.

Recalibrating a scope is not easy and you need lots of expensive gear for it. Like timemarker of timestandard, a calibrated voltage source, very stable generators and often a fast pulse generator. If not, you will only make it worse, besides that, without those you will not know if it is still calibrated

Instead buy a book about electronics, like the art of electronics, electronics for dummys, electronics 101 and there are many more.

Some one with knowledge can repair more with just a multimeter as someone without knowledge and a room full of test equipment. If you hook up your scope, you must know what to expect in front so you know if what you see is correct. Otherwise it are just meaningless figures on a screen.

If you want to know how a scope works, download a Tektronix 535, 545, 547, 465 ect manual. The opertation chapters are very clear and tell all the basics.

Some example for your wive. If the TV dies and you suspect the caps, you now look ith your scope id there is to much ripple current on the power supply lines and so find out if the caps are indeed bad. But you need a schematic for that, recognize parts and know where to measure what without frying yourself or your scope on the high voltages in side ( upto a few KV in televisions or monitors, and not by accident probe the live part of the SMPS of patient without diff probes or an isolation transformer.

So first some basic knowlegde and then if a scope. ( then you also know what scope and how to test it) and with some knowledge it is much more fun

Now it is more like asking how to build a house only because you want to buy a hammer.

[Error_code]

yea, one day i will have more free time to sit and learn all that stuff...

At work, in the IT dept (which i have access)... we got couple of guys that do electronic repair.  They are experienced electronic guy. Theire work space is like junkyard full of opened devices and parts. And they say that its even worst at their house...i have no doubt....  I can only imagine their wife going into the basement.   My wife will not like me very much if i start stacking broken devices...  yea she wants the house super clean, that means no useless thing.

At work, the electronic guys are busy so they can't show us ( us the IT guys) how they do... but we can watch them work (if we're not busy...but we're also very busy).

I learned few things while watching them repairing CRT... like where no to put your finger on...  i'm fully aware of high voltage 

They know where to put the probe when they look at circuit boards and i noticed how careful they are. 

But you got to agree that scopes are cool, so cool you see them in music videos like in the post above 

[PA4TIM]

I agree they are cool, i have several ( 8 at my lab and some more in storage) my most expensive analog scope was a 150 MHz Tek with new probes for 125 euro, the next a 7704 and 7603 with 3 plugins for 75 euro a piece, the rest was for free. ( but often not working)

The most cool one for me is still my Tek 547 including scope mobile and around 15 plugins. The thing is huge, if you do not put the brake on the scopemobile the fan will probably blow it through the lab  and it produces anough heat to warm the room in winter, and the fan makes enough sound so you do not hear your wife wining about the mess 

But again, it will be decoration only because you will have no clue what to do with it and 100 dollar for the youtube thing ?? Or do you want to do that every day ?