Author Topic: Please help me get a oscilloscope  (Read 15894 times)

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Online tggzzz

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Re: Please help me get a oscilloscope
« Reply #25 on: July 23, 2017, 06:12:21 am »
... there is no way i need the functionality of digital storage, and neither did the engineers until the late 1980's

Actually, we did need them - but the ADC technology wasn't sufficient. So we had to use analogue storage scopes where the storage is in the tube itself.

You can still find them around; my local HackSpace has a donated Telequipment 63, and I picked up a Tek 464 for free from a local equivalent of Craigslist. After the usual light repair, they work and are an excellent reminder of why people switched to digitising storage scopes as soon as they became usable.

Such analogue storage isn't new: some early computer memories were made as charges stored on the inside of a CRT; see https://en.wikipedia.org/wiki/Williams_tube
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline Someone

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Re: Please help me get a oscilloscope
« Reply #26 on: July 23, 2017, 06:48:31 am »
... there is no way i need the functionality of digital storage, and neither did the engineers until the late 1980's
Actually, we did need them - but the ADC technology wasn't sufficient. So we had to use analogue storage scopes where the storage is in the tube itself.
Well so far we have a post saying they wish to measure frequency so need a scope, again jumping for the easy answer. An oscilloscope can measure many things but it has its limitations (and expense) while a lot of measurements can be made in numerous ways with other techniques and tools, measuring frequency can be as simple as a speaker and a tuning fork or musical instrument, or a cheap multimeter, or a stroboscope, or a counter. Many of us would recall doing fine in the hobby space without a scope by using other methods, and this comes in use when you are trying to measure something and can't access it with desired tools.

Some things are nice to have but they aren't needed.
 

Offline Halcyon

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Re: Please help me get a oscilloscope
« Reply #27 on: July 23, 2017, 06:56:33 am »
Get a job.  Earn some money.  Buy one.

Pretty piss poor advice. As others have pointed out, it's not that easy, in fact, most countries have a minimum age where someone can be legally employed and be paid. In Australia it's 14 years and 9 months old. That's when I got my first job.

I respect the kid, he knows what he wants and he is doing his best. At least he has a keen interest in something useful, not hanging out with a "bad crowd" or wasting his day away at a skate park.
 
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Online tggzzz

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Re: Please help me get a oscilloscope
« Reply #28 on: July 23, 2017, 06:59:29 am »
... there is no way i need the functionality of digital storage, and neither did the engineers until the late 1980's
Actually, we did need them - but the ADC technology wasn't sufficient. So we had to use analogue storage scopes where the storage is in the tube itself.
Well so far we have a post saying they wish to measure frequency so need a scope, again jumping for the easy answer. An oscilloscope can measure many things but it has its limitations (and expense) while a lot of measurements can be made in numerous ways with other techniques and tools, measuring frequency can be as simple as a speaker and a tuning fork or musical instrument, or a cheap multimeter, or a stroboscope, or a counter. Many of us would recall doing fine in the hobby space without a scope by using other methods, and this comes in use when you are trying to measure something and can't access it with desired tools.

Some things are nice to have but they aren't needed.

Indeed - look at my .sig and replace "span" with "scope".

At school we were taught how to measure voltage to 0.1% with a 2% voltmeter, a piece of wire, a metre rule, and two cells. One cell could supply current but the voltage varied, one had a known voltage but couldn't supply any current whatsoever (and contained mercury and cadmium solutions).
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline Electro Detective

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Re: Please help me get a oscilloscope
« Reply #29 on: July 23, 2017, 08:35:22 am »
Get a job.  Earn some money.  Buy one.

Pretty piss poor advice. As others have pointed out, it's not that easy, in fact, most countries have a minimum age where someone can be legally employed and be paid. In Australia it's 14 years and 9 months old. That's when I got my first job.

I respect the kid, he knows what he wants and he is doing his best. At least he has a keen interest in something useful, not hanging out with a "bad crowd" or wasting his day away at a skate park.

 :-+ 

...and he's hooked up with one of the better forums   :clap:



« Last Edit: July 23, 2017, 09:04:28 am by Electro Detective »
 

Offline fcb

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Re: Please help me get a oscilloscope
« Reply #30 on: July 23, 2017, 11:56:53 am »
I bought my first 'scope (Telequipment DM64) on my 13th birthday - it cost me £130 from Henry's on Tottenham Court Road in 1985, this was every penny I saved for a couple of years.  So I can sympathise with Brett's desire for a 'scope.

That said I think we should be wary about suggesting an old analogue 'scope - he may get lucky and get a good one, on the other hand he may get a duffer - and who is going to suggest that an inexperienced 13yo should be poking about inside a CRT 'scope.

I would suggest Brett try and find either a maker/hacker space locally or a HAM radio club. Highly likely that someone will have spare gear and also be able to show him how to use it safely.

More explanation as to why he needs a 'scope would help.  If it was audio, then there are apps for the ipad that turn it into a basic 'scope, if it's digital - then those $10 8ch digital logic analysers might be a great place to start (probably need an old PC - but that's trivial to get compared with 'scope).

Either way - I wish Brett good luck, please keep up with the thread.
« Last Edit: July 23, 2017, 11:59:08 am by fcb »
https://electron.plus Power Analysers, VI Signature Testers, Voltage References, Picoammeters, Curve Tracers.
 

Offline MK14

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Re: Please help me get a oscilloscope
« Reply #31 on: July 23, 2017, 12:50:59 pm »
For around $15, you can get these simple beginners oscilloscopes.

N.B. If you do buy one. Get advise (here) from someone who knows more about them. As some of the kits are better/best, than others. I DON'T know which are the best ones, as I DON'T have one.

You could have fun building it (if so, it is probably worth the $15 as an electronics project), and learn a lot, both from building it, seeing/understanding how it works, and then playing with it.
If you then told people about your experiences with it and/or did a youtube video, showing people, how good or bad, you found it. Maybe some fun projects you did with it.
You may get more people interested in helping you, sort out how you get yourself an oscilloscope.

If you do get an analogue one, make sure that it is NOT too big for your work bench and storage capabilities. If it is, you can either get a rather small analogue oscilloscope (some are smaller), or somehow earn/raise enough to buy your first proper digital oscilloscope. The later digital ones (usually LCD), are usually much more compact than the old analogue oscilloscopes.

http://www.ebay.com/itm/DSO138-2-4-TFT-Digital-Oscilloscope-Acrylic-Case-DIY-Kit-SMD-Soldered-New-R2C0-/172351258235?var=&hash=item2820ef7e7b:m:mMasFJ1Und7ykMSUF3yEFqQ

« Last Edit: July 23, 2017, 12:53:52 pm by MK14 »
 

Online CatalinaWOW

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Re: Please help me get a oscilloscope
« Reply #32 on: July 23, 2017, 01:44:43 pm »
I will add to Terrahertz suggestions for your go fund me account.

Tell more of your story.  What have you done in electronics since you took the radio apart?  What have you built, what have you read, what have you measured?  What are you hoping to do with the scope when you get it?  Which part of electronics fascinates you - is it radio or controls or power or digital logic or ....  It is OK to not have a single pick or even a few, but all you can do to talk about them will help your quest.

I will also partly agree with those who suggest getting a job.  A lot will depend on your home situation and the local community, but often commitment leads to rewards.  Just hanging around a local shop which does something "technical" can lead to odd jobs or informal work or donations.  The local shop could be a maker space, a lawn mower repair shop, or if you are really, really fortunate, someone who repairs electronics (they exist though rare as hens teeth these days.)

I would also suggest that there is much to learn and explore in electronics before you need an oscilloscope.  Voltage dividers.  Simple power supplies.  Simple logic.  You haven't mentioned whether you have a voltmeter or DMM or any other test gear yet.  Something as simple as the free Harbor Freight DMM (actually will cost as much as two or three dollars since you may need to buy a Sunday newspaper to get the coupon and since a purchase is required and the cheapest thing I am aware of in the store is a snap off knife for 49  cents which you can use the 20% off coupon on). 

Get to the library or internet and look for old books on electronics.  The electronics engineers who designed the first radars and televisions did not have oscilloscopes to start with, they invented them as part of their work.  Much of what they did have can be duplicated easily and cheaply today, and following them through the learning/invention process is a great learning tool.
 

Offline tooki

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Re: Please help me get a oscilloscope
« Reply #33 on: July 23, 2017, 02:21:32 pm »
  Humbug must humbug. At least the kid is taking some initiative, some action.
 

No he's not. This is not how the world works.
You might wanna read up on how Steve Jobs got started in tech.
 

Offline PlainName

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Re: Please help me get a oscilloscope
« Reply #34 on: July 23, 2017, 07:49:48 pm »
Quote
For the naysaying scrooges - he's 13

And Dunkem High is actually my real  name.

JOOI, how do you know he is 13?
 

Offline hermit

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Re: Please help me get a oscilloscope
« Reply #35 on: July 23, 2017, 08:17:51 pm »
Quote
For the naysaying scrooges - he's 13

JOOI, how do you know he is 13?
Someone joins an electronics forum and and their first post is for $500 in donations?   ::)  If they are that interested where is the previous participation?  With so many scams now days my money isn't given that freely.
 
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Offline WastelandTek

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Re: Please help me get a oscilloscope
« Reply #36 on: July 23, 2017, 08:21:44 pm »
here kid

http://www.zelscope.com/

don't say I never did anything for 'ya
I'm new here, but I tend to be pretty gregarious, so if I'm out of my lane please call me out.
 

Offline grumpydoc

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Re: Please help me get a oscilloscope
« Reply #37 on: July 23, 2017, 08:33:35 pm »
I bought my first 'scope (Telequipment DM64) on my 13th birthday - it cost me £130 from Henry's on Tottenham Court Road in 1985, this was every penny I saved for a couple of years. 
You beat me by a few years.

I guess I was 16, maybe 17 when I got my first 'scope. I don't recall the make - something like a Telequipment D67 but I do remember visiting Steward of Reading to buy it - with hard saved funds. I think it was also around the £100 mark - I struck a deal because one channel wasn't working. I figured I could use the good channel to trace through the bad - in truth I probably would not have stood a chance but I got very lucky. It must have been a dry joint or dodgy switch because after the jostling of the train journey home it worked and continued to do so perfectly until some low life *&^^%$£ stole it from my car when I was about 24.
 

Offline hermit

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Re: Please help me get a oscilloscope
« Reply #38 on: July 23, 2017, 08:39:03 pm »
Here is an old Tek 2213 for $35 near you.
https://cleveland.craigslist.org/bfs/d/for-sale-tektronix-analog/6211924909.html
Give the guy a call, and he might even be willing to give it to you for free.
Geez the link disappeared after I bought the thing.  Go figure.   Thanks for the heads up on that.  :-+ I had to drive to Cleveland for it, but it came with a bag full of probes.   Fortunately, one was bad.  It was the one connected to the thing when I got there and caused at least one other person to decline the purchase.  I had an Arduino and attached dongle to output something I could easily look at. 

 

Offline eugenenine

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Re: Please help me get a oscilloscope
« Reply #39 on: July 23, 2017, 09:32:13 pm »
There is a 2264 in c-bus, I'd buy it but I don't have $275
https://columbus.craigslist.org/ele/d/tektronix-channel-mhz/6213159523.html

I have a 2205 and a 2211.
 

Offline Vgkid

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Re: Please help me get a oscilloscope
« Reply #40 on: July 23, 2017, 11:25:23 pm »
I have a 2246 as my only oscilloscope.
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Offline eugenenine

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Re: Please help me get a oscilloscope
« Reply #41 on: July 23, 2017, 11:36:57 pm »
Looking at the location on the map I know the seller, I bought a fluke meter from him a while back.

Maybe I should ask him to give it to me :)
 

Offline vk6zgo

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Re: Please help me get a oscilloscope
« Reply #42 on: July 25, 2017, 12:01:37 am »
... there is no way i need the functionality of digital storage, and neither did the engineers until the late 1980's

Actually, we did need them - but the ADC technology wasn't sufficient. So we had to use analogue storage scopes where the storage is in the tube itself.

You can still find them around; my local HackSpace has a donated Telequipment 63, and I picked up a Tek 464 for free from a local equivalent of Craigslist. After the usual light repair, they work and are an excellent reminder of why people switched to digitising storage scopes as soon as they became usable.

Such analogue storage isn't new: some early computer memories were made as charges stored on the inside of a CRT; see https://en.wikipedia.org/wiki/Williams_tube

I could count the number of times I actually needed  a storage oscilloscope on the fingers on one hand, over many years in Electronics.
There were more times when it would have been handy, but even they were fairly rare.

But then, again, I'm not an Engineer!  ;D

Those 'scopes with analog storage fell into one of two categories:-
(1)The storage function had never been used.
(2)The storage controls were worn out, so the pot position you needed was right in the noisy part of the track

When HP brought their "latest & greatest" DSO we were enthusiastic, but were disappointed in its performance, for other reasons.(Lack of memory made it useless for video testing.)
This was repeated with both HP & Tektronix for years.

Perhaps naively, I thought that digital storage would allow us to save a good waveform, superimpose the one we were looking at, then compare them, but such a facility did not exist, at least in the early 1980s/1990s instruments.
Indeed, does it exist now?




 

Offline aargee

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Re: Please help me get a oscilloscope
« Reply #43 on: July 25, 2017, 01:43:25 am »
Get a job.  Earn some money.  Buy one.

Pretty piss poor advice. As others have pointed out, it's not that easy, in fact, most countries have a minimum age where someone can be legally employed and be paid. In Australia it's 14 years and 9 months old. That's when I got my first job.

I respect the kid, he knows what he wants and he is doing his best. At least he has a keen interest in something useful, not hanging out with a "bad crowd" or wasting his day away at a skate park.

... or collecting obscene amounts of test gear that will never be used.  :-DD
Not easy, not hard, just need to be incentivised.
 

Offline hermit

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Re: Please help me get a oscilloscope
« Reply #44 on: July 25, 2017, 03:58:11 am »
... or collecting obscene amounts of test gear that will never be used.  :-DD
Those giving verbal support never gave financial support.  No donations as of yet.  Seriously, that $35 60Mhz scope was quite the recommendation IF this is an honest  endeavor.  But, I own it now.   Beats the 1Mhz tube based scope I was begged to take away.  But, look at that board on his desk.  It really needs a $500 scope to analyze, because Lord knows, it will kill his 'real' interest if he doesn't get that $500 scope.  Need and want are still different last I checked.
 

Offline PlainName

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Re: Please help me get a oscilloscope
« Reply #45 on: July 25, 2017, 01:06:57 pm »
Quote
But, I own it now

Why did you buy it?
 

Offline testpoint

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Re: Please help me get a oscilloscope
« Reply #46 on: July 25, 2017, 01:26:53 pm »
when I am in 13 years old, I try to get a multimeter, but my family is poor in that time, I can not get it, to determine the DC power supply's +- line, I just put the line into water, more gas bubble is negative K, another one is positive A;
please give me a reason why you want the scope ? I have several, may give you in free, but the shipping cost is quite high, you may wait one year, until I move to MA, USA.
 
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Offline NivagSwerdna

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Re: Please help me get a oscilloscope
« Reply #47 on: July 25, 2017, 01:34:25 pm »
FWIW OP also appears here... https://www.eevblog.com/forum/contests/giveaway-rohde-schwarz-rtb2004-oscilloscope/msg1245118/#msg1245118

Just because you don't own something doesn't mean it you can't get access to it... IMHO In the meantime OP needs to seek out a school, ham radio club, colege, hack space... finding a mentor would help a lot.  (I used to hang out around University departments many years before ever being an under grad, academics can be amazingly friendly to keen young people). [Obviously under some oversight of parent... child protection issues etc etc!]
« Last Edit: July 25, 2017, 01:58:33 pm by NivagSwerdna »
 

Offline onesixright

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Re: Please help me get a oscilloscope
« Reply #48 on: July 25, 2017, 02:05:52 pm »
Get a job.  Earn some money.  Buy one.
Pretty piss poor advice. As others have pointed out, it's not that easy, in fact, most countries have a minimum age where someone can be legally employed and be paid. In Australia it's 14 years and 9 months old. That's when I got my first job.

I respect the kid, he knows what he wants and he is doing his best. At least he has a keen interest in something useful, not hanging out with a "bad crowd" or wasting his day away at a skate park.

I don't think you need a license to cut grass, wash a few cars, shine some shoes? Or do you? A few weeks and you have 50 USD, enough to buy a analog scope.

What I don't get is where the need comes from? To want stuff, I understand. But need when your 13?

It wouldn't be my style to beg ask for free stuff. But some people simply don't mind. Can't blame the boy, I guess (maybe?) this has todo with upbringing? My mother would slap me around, pretty sure.

@Stonecold I do wish you success! But, if I could give you once peace of advice, try to manage on your own (meaning: don't depend on gifts). The reward will be much greater (and you will enjoy it much longer). Promise.

// off topic
It would make law enforcement pretty simple (and its not) if you could distinguish bad crowds just based wetter you would be asking for stuff on some forum. Plenty scammers online. I don't think this would be a indication of anything. 

There are gang-members that are "keen" to join the US army, not help, but to learn. And these guys, once they are coming back (after service), have no intention to use what they learned for the greater good. In the contrary. My point? Being keen on learning stuff, says nothing about the (true) motivation.


 

Offline hermit

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Re: Please help me get a oscilloscope
« Reply #49 on: July 25, 2017, 02:17:01 pm »
Why did you buy it?
That's answered in the post.  But to add, my 1MHz tube based, rack mount scope is starting to have issues.  At $35 I figured it was worth the gamble.  But mainly, at $35 I'd probably buy a second just based on price if it became available.
 


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