Author Topic: Should I buy an oscilloscope ?  (Read 21737 times)

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Offline prayag2010

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Should I buy an oscilloscope ?
« on: March 02, 2013, 05:08:20 pm »
Hello everyone,

 I am a beginner in electronics and I am looking forward to set up a workbench. But, I had a question;
Should I buy an oscilloscope ? It is too costly and I am not sure if I truly need it. Instead, should I buy two decent multimeters and other necessities ?
 

Offline c4757p

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Re: Should I buy an oscilloscope ?
« Reply #1 on: March 02, 2013, 05:13:48 pm »
It is too costly ...

Then don't buy one. An oscilloscope can be incredibly useful at times, but if you genuinely can't afford one, remember - hobbyists got by without them for decades before the price made them accessible. A lot of things can be done without an oscilloscope by applying a bit of cleverness.

That said - I don't know where you live, but if you look in the right places and have patience, you should not be surprised to find one for free or very close to it. It won't be a 350 MHz four-channel monster, but it will be an oscilloscope.
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Online mikeselectricstuff

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Re: Should I buy an oscilloscope ?
« Reply #2 on: March 02, 2013, 06:02:23 pm »
Definitely yes - even an old, cheap/free analogue one is a lot better than nothing.
A scope IS a necessity for any non-trivial electronics work, and will help you learn.
Remember test gear generally holds value well.
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Offline prayag2010

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Re: Should I buy an oscilloscope ?
« Reply #3 on: March 02, 2013, 06:55:14 pm »
Definitely yes - even an old, cheap/free analogue one is a lot better than nothing.
A scope IS a necessity for any non-trivial electronics work, and will help you learn.
Remember test gear generally holds value well.
It is too costly...

That said - I don't know where you live, but if you look in the right places and have patience, you should not be surprised to find one for free or very close to it. It won't be a 350 MHz four-channel monster, but it will be an oscilloscope.




I am planning to buy an analogue one. Any suggestions ??
 

Online BravoV

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Re: Should I buy an oscilloscope ?
« Reply #4 on: March 02, 2013, 07:01:11 pm »
I am planning to buy an analogue one. Any suggestions ??

Since you mentioned analog, I assume you're aiming for used and cheap one.

Two most important questions regarding asking for suggestion on buying used / analog scope :

- Where do you live ?
- What is the max budget ?

Nothing to suggest if these are not answered.

Online nctnico

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Re: Should I buy an oscilloscope ?
« Reply #5 on: March 02, 2013, 07:36:10 pm »
Definitely yes - even an old, cheap/free analogue one is a lot better than nothing.
A scope IS a necessity for any non-trivial electronics work, and will help you learn.
I strongly agree. I got an oscilloscope when I was 14 and it served me extremely well.
Quote
Remember test gear generally holds value well.
I strongly disagree. Test equipment in general devaluates faster than a mobile phone. Just look at the selling prices on Ebay and do the math. So buy something with the specs you need now and spend more money later when necessary.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online AndyC_772

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Re: Should I buy an oscilloscope ?
« Reply #6 on: March 02, 2013, 09:28:35 pm »
I sold my last scope for about what I paid for it, and based on current Ebay prices, I could quite easily expect to make a profit on my current scope even though I've had it for a couple of years. Buy something old but decent and working and you should be fine.

Offline EEVblog

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Re: Should I buy an oscilloscope ?
« Reply #7 on: March 02, 2013, 09:32:51 pm »
YES.
Beg or borrow an oscilloscope.
It is possible to buy an old analog oscilloscope for the price of a cheap multimeter.

Dave.
 

Offline MetraCollector

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Re: Should I buy an oscilloscope ?
« Reply #8 on: March 02, 2013, 09:42:53 pm »
When I have some visit at my's and comment my osciloscope I reply "A home without a scope isn't real home." ;D
 

Offline Hydrawerk

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Re: Should I buy an oscilloscope ?
« Reply #9 on: March 02, 2013, 09:45:19 pm »
Should I buy an oscilloscope ?
Yes, you should. But not soviet H313 model. I have it since I was a little child... It was my father's scope... But this scope is crap. It has unstable trigger and much more... Note the small screen and strange input connectors. They are not BNCs.
(Picture not taken by me!)
Anyway, this was my first scope and it still taught me something... I saw the sine wave for the first time. So if you have little money, buy a cheap simple old scope, it will be even useful for you...
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Online AndyC_772

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Re: Should I buy an oscilloscope ?
« Reply #10 on: March 02, 2013, 10:03:07 pm »
Lol :) Maybe not, but a scope like my old Fluke PM3082 would have been ideal - 4 channels, 100 MHz, a proper analogue scope but with a few more modern, useful features like on-screen cursors. I sold it including a complete set of probes for £150.

Offline Wuerstchenhund

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Re: Should I buy an oscilloscope ?
« Reply #11 on: March 02, 2013, 10:23:40 pm »
I strongly disagree. Test equipment in general devaluates faster than a mobile phone.
Unless you have an iPhone or something super exclusive like a phone from Vertu that is not true, and even iPhones deprecate much faster than brand name test equipment. Most cell phones have lost any noticeable market value within 2 or 3 years, some models may extend that to 5 years, but that's it. A 15 year old scope like say a HP 54542C (4Ch 500MHz 2GSa/s) which, when new, was probably around $20k mark, still goes for $1500+. It's the same for most other test equipment, often enough even stuff from the 60's/70's still fetches remarkable prices.

That most certainly will be different for China T&M like Rigol, Atten/Siglent, Hantek or whatever new name they come up with to sell their toys.

Quote
Just look at the selling prices on Ebay and do the math.

The best is to look at the prices stuff is actually sold, not the overinflated asking prices of many (mostly US) dealers that relist the same item again and again for over a year in the hope they find an idiot who pays their ridiculous prices.
 

Online nctnico

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Re: Should I buy an oscilloscope ?
« Reply #12 on: March 02, 2013, 10:29:06 pm »
I sold my last scope for about what I paid for it, and based on current Ebay prices, I could quite easily expect to make a profit on my current scope even though I've had it for a couple of years. Buy something old but decent and working and you should be fine.
There are always exceptions to the rules. Sometimes you can get lucky and have a chance to buy equipment from someone who has no clue about what he is selling or what it is worth.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline PaulAm

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Re: Should I buy an oscilloscope ?
« Reply #13 on: March 02, 2013, 10:42:05 pm »
You ought to be able to find a usable analog scope from the 70s-90s with 100MHz bandwidth or better, two channel, delayed sweep for under $100.  That will do everything you need to do for a while.  If you have more money, you can look for a Tek 24xx series which has onscreen cursors.  If the scope breaks you can fix it, which is an even better learning experience. HP and Tek scopes of that era have all kinds of service information easily available as well as communities of people who like to work on them.  Advice, sometimes useful, is easy to get.  I have bought numerous scopes of that era for $50 or less.  Some of those have even been 100% functional.

I think scopes are very useful in understanding what is happening with a circuit you built.  You can put probes on the input and output of a circuit and see what happens as you change component values.  It's a great teaching tool

When you get to the point when the analog scope doesn't do everything you need, then you can move up to a DSO, but you'll have a pretty good understanding of what to look for at that point.

I just bought a Tek 422 off of craigslist for $35 the other week.  It's only a 15MHz scope, but it's small, dual channel and portable, as well as being an antique.  I'm going to throw it in my shop next to the cnc equipment.
 

Online mikeselectricstuff

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Re: Should I buy an oscilloscope ?
« Reply #14 on: March 03, 2013, 12:33:42 am »
Quote
Remember test gear generally holds value well.
I strongly disagree. Test equipment in general devaluates faster than a mobile phone. Just look at the selling prices on Ebay and do the math. So buy something with the specs you need now and spend more money later when necessary.
I should maybe have qualified that with "used" equipment - everything loses quite a lot from 'new' to 'used', but the useable life of a reasonable scope or other test gear is an order of magnitude longer than any consumer electronics.  Comparison with a phone is just ridiculous.
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Online nctnico

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Re: Should I buy an oscilloscope ?
« Reply #15 on: March 03, 2013, 01:41:57 am »
I strongly disagree. Test equipment in general devaluates faster than a mobile phone.
Unless you have an iPhone or something super exclusive like a phone from Vertu that is not true, and even iPhones deprecate much faster than brand name test equipment. Most cell phones have lost any noticeable market value within 2 or 3 years, some models may extend that to 5 years, but that's it. A 15 year old scope like say a HP 54542C (4Ch 500MHz 2GSa/s) which, when new, was probably around $20k mark, still goes for $1500+. It's the same for most other test equipment, often enough even stuff from the 60's/70's still fetches remarkable prices.
20k-1500=14500 which is about $1000 a year. I wouldn't call that keeping its value. A car depreciates at about the same rate. Besides, in some countries there is a big market for second hand phones because people simply can't afford new ones.
Quote
Quote
Just look at the selling prices on Ebay and do the math.

The best is to look at the prices stuff is actually sold, not the overinflated asking prices of many (mostly US) dealers that relist the same item again and again for over a year in the hope they find an idiot who pays their ridiculous prices.
That is what I tried to say. Selling prices, not asking prices  ;)
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline c4757p

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Re: Should I buy an oscilloscope ?
« Reply #16 on: March 03, 2013, 01:48:17 am »
20k-1500=14500 which is about $1000 a year.

That's like saying that if somebody is 100 years old and weighs 100 pounds they gained one pound per year. The depreciation is highly nonlinear, and by the time you buy that used scope, its value will be relatively fixed for the time you own it. By the time you go to sell it again, it will not have lost much.
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Offline prayag2010

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Re: Should I buy an oscilloscope ?
« Reply #17 on: March 03, 2013, 07:37:16 am »
Thank you everyone for your help.

I live in Mumbai, India, and  I will try to look for one although I highly doubt that I will find any. I think that will start looking for good deals on ebay...
 

Offline mzzj

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Re: Should I buy an oscilloscope ?
« Reply #18 on: March 03, 2013, 09:17:00 am »


I live in Mumbai, India, and  I will try to look for one although I highly doubt that I will find any. I think that will start looking for good deals on ebay...

That changes things a bit. In my experience used professional tools are (lot) more expensive in developing countries, things developing fast and there is always someone in the need of equipment.

Shipping for any of the bigger, older models is going to be expensive if you order from abroad. Plus you may have to pay suprisingly high taxes or be prepared with some "tea money" 

I just checked indian ebay and did not see anything reasonable locally.

Cheapest usb-scope that looks usable: http://www.ebay.co.uk/itm/New-DSO2090-PC-USB-40MHZ-100MS-s-Digital-Storage-Oscilloscope-/230770204768?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item35baf9e060.

Or stand-alone http://www.ebay.co.uk/itm/Atten-Digital-Oscilloscope-60MHz-ADS1062CAL-1GSa-s-Sampling-2-CH-LCD-/280946420533?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item4169b62b35#shId
 

Offline Wuerstchenhund

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Re: Should I buy an oscilloscope ?
« Reply #19 on: March 03, 2013, 09:24:37 am »
Unless you have an iPhone or something super exclusive like a phone from Vertu that is not true, and even iPhones deprecate much faster than brand name test equipment. Most cell phones have lost any noticeable market value within 2 or 3 years, some models may extend that to 5 years, but that's it. A 15 year old scope like say a HP 54542C (4Ch 500MHz 2GSa/s) which, when new, was probably around $20k mark, still goes for $1500+. It's the same for most other test equipment, often enough even stuff from the 60's/70's still fetches remarkable prices.
20k-1500=14500 which is about $1000 a year. I wouldn't call that keeping its value. A car depreciates at about the same rate.

Hmm..my math says that 20000 minus 1500 is more along the lines of 18500, but never mind.

So clearly by your logic, buying a house (which costs you more than a grand a months just to pay it off over 20 years) is never good value because you can get other things like cars, rubber boats, cell phones for a lot less, right?

Well, unfortunately that's not how it works. There's a reason why in finance depreciation is usually calculated in percentage of an item's purchase price over a defined period. Looking at your $600 cell phone which after four years is worth say $50 (which is approx. 8.3% of its purchase price), you end up loosing $550 (or approx. 91.7% of its purchase price) over 4 years or, annually (at linear progression) roughly $137.50 or approx. 22.92%. So in short, your precious little phone loses almost a quarter of its purchase price a year.

Let's look at the scope: $20k when new and still selling at $1500 after 15 years. That means that, over 15 years (a usage time which btw far extends the one of your average cell phone!), at linear progression it lost $18500 92.5% of it's value. That sounds like a lot but actually the annual progression is just around 6.2% of its original purchase price.

And out in the world, an item that in average only looses 6.2% of value a year is considered to be much more value retaining than an item that looses 22.92% a year.

Of course this is a very simplified view, and there are a wide range of progression methods (most items depreciate in a non-linear way), but it covers the essentials. Just because even a small progression means a large amount of money for an originally very expensive item doesn't mean it is not holding value well. The absolute amount however comes into play when you have to consider if getting a $20k scope is worth it for the job. You take the purchase price, estimate the remaining value at the end of the usage period (which for T&M equipment usually is somewhere between 5 to 7 years), and calculate the annual progression. If the calculation then shows that the scope costs you more than it actually 'earns' for the job, it's not worth it.

Quote
Besides, in some countries there is a big market for second hand phones because people simply can't afford new ones.

Sure, like for almost any other items that do not degrade, disintegrate, explode or become otherwise useless after a short amount of time. But that doesn't change the fact that cell phones hold their value rather badly (the market offerings is much larger than the demand, something that is not generally true for T&M kit).
 

Offline SeanB

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Re: Should I buy an oscilloscope ?
« Reply #20 on: March 03, 2013, 10:50:06 am »
Vehicles depreciate the most in the first year, typically losing 20-30% of value, then the curve flattens off. In some cases after 20 years the value will be more than the original cost, just due to inflation. As an example a $30k BMW will typically be $25k after a year, and $20k after 4 years ( 10k after 6 years because then Motorplan has run out, which causes a big drop in perceived value) while after 10 years the value will be still around $8k and then depend on condition. Test gear follows a similar curve, while it is supported by the manufacturer it has a lot of value, but will drop when support ends to a lower level and then trend to stay at that point for a long time until they become scare and then trend up as spare parts for those still using them.
 

Offline prayag2010

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Re: Should I buy an oscilloscope ?
« Reply #21 on: March 03, 2013, 12:28:24 pm »


I live in Mumbai, India, and  I will try to look for one although I highly doubt that I will find any. I think that will start looking for good deals on ebay...

That changes things a bit. In my experience used professional tools are (lot) more expensive in developing countries, things developing fast and there is always someone in the need of equipment.

Shipping for any of the bigger, older models is going to be expensive if you order from abroad. Plus you may have to pay suprisingly high taxes or be prepared with some "tea money" 

I just checked indian ebay and did not see anything reasonable locally.

Cheapest usb-scope that looks usable: http://www.ebay.co.uk/itm/New-DSO2090-PC-USB-40MHZ-100MS-s-Digital-Storage-Oscilloscope-/230770204768?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item35baf9e060.

Or stand-alone http://www.ebay.co.uk/itm/Atten-Digital-Oscilloscope-60MHz-ADS1062CAL-1GSa-s-Sampling-2-CH-LCD-/280946420533?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item4169b62b35#shId



I think that I can buy that atten one. What are your views regarding that oscilloscope ?
 

Online nctnico

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Re: Should I buy an oscilloscope ?
« Reply #22 on: March 03, 2013, 02:42:28 pm »
Or maybe a Siglent which is a bit cheaper:
http://www.ebay.com/itm/Siglent-SDS1062C-Digital-Oscilloscope-60MHZ-DS1052E-/330872374375

I think this will be a good entry level scope. BTW Lecroy sells rebadged Siglent equipment to cover the lower end of the market. Based on the teardowns on this website I have a feeling Siglent is a bit better than Atten.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline prayag2010

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Re: Should I buy an oscilloscope ?
« Reply #23 on: March 03, 2013, 03:02:40 pm »
What about Rigol DS1052E  ?
 

Offline mzzj

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Re: Should I buy an oscilloscope ?
« Reply #24 on: March 03, 2013, 03:29:58 pm »
Or maybe a Siglent which is a bit cheaper:
http://www.ebay.com/itm/Siglent-SDS1062C-Digital-Oscilloscope-60MHZ-DS1052E-/330872374375

I think this will be a good entry level scope. BTW Lecroy sells rebadged Siglent equipment to cover the lower end of the market. Based on the teardowns on this website I have a feeling Siglent is a bit better than Atten.

I was going to mention about Siglent, but it didn't show up on ebay search for some reason when I was searching with "postage to India" option. Now I did another search and actually found some. I agree  it is probably somewhat better than Atten.

http://www.ebay.co.uk/itm/Siglent-SDS1052DL-7-50MHZ-500MSa-s-32Kpts-Digital-Storage-Oscilloscope-/170997697398?pt=AU_B_I_Electrical_Test_Equipment&hash=item27d041cb76

I would imagine that there is electronic equipment stores also in Mumbai worth checking local price level for Siglent/Atten/Rigol/Owon scopes. Finding those stores might be a different thing  :P
As I remember diyaudio.com has some active users from India sourcing components and tools, ie http://www.diyaudio.com/forums/parts/176167-parts-mumbai-india.html

Edit: Rigol is  for sure tried and proven product, if it fits Your budget I think it's a excellent alternative.
 


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