Help buying an oscilloscope

Thread Starter

adam555

Joined Aug 17, 2013
858
Would you buy or recommend to a beginner this oscilloscope as a cheap option...

It's Russian, so if the text bellow looks odd it's because it's translated.



Oscilloscope C1-118A is designed to monitor and measure the electrical
signals with an amplitude of 5 mV - 400 V and a duration of 80 ns - 0.5. TV-sync. Due to its small size and low cost, the unit C1-118A is used in the repair of electronic services radioaparatury, amateurs and educational institutions.
  • Vertical deflection
    • The bandwidth of 0-20 MHz
    • The rise time of 35 ns HRP
  • Odds
    • deviation of 5 mV / div - 5 V / div
    • Sweep 0.02 ms / div - 50 ms / div
    • Limits of error of deflection factors sweep ± 4%
    • Input resistance, capacitance 1 M, 30 pF
  • Calibrator
    • Output voltage: a rectangular pulse amplitude of 12 V (2% error)
  • Effective screen 60 x 80 mm
  • Power 220 ± 22, 50 ± 0,5 Hz or 60 Hz ± 0,6
  • Power consumption 28 VA
  • Dimensions 120 x 210 x 300 mm
  • 4 Weight kg
 

MrChips

Joined Oct 2, 2009
30,720
Shop around for a used analog Tektronix scope. They are built to last.
Make sure you get a pair of decent probes. As you found out, new probes can cost as much as a used scope.
 

Rbeckett

Joined Sep 3, 2010
208
I bought a Beakman 9010 and a 9020 sig generator for less than a hundred bucks delivered. 2 channels , 20 Mhz nice for the money and more than adequate for my electronics knowledge and experience. Check Ebay and Craiglist closely.

Wheelchair Bob
 

DerStrom8

Joined Feb 20, 2011
2,390
I would recommend a scope that can measure in the uS range. Do as MrChips suggested and go for a quality scope with all the features. It may cost a little bit more at first, but I can guarantee 100% you won't regret it. I can't say the same for cheap Russian scopes. Just get a good one. Period.
 

Thread Starter

adam555

Joined Aug 17, 2013
858
Shop around for a used analog Tektronix scope. They are built to last.
Make sure you get a pair of decent probes. As you found out, new probes can cost as much as a used scope.
I would recommend a scope that can measure in the uS range. Do as MrChips suggested and go for a quality scope with all the features. It may cost a little bit more at first, but I can guarantee 100% you won't regret it. I can't say the same for cheap Russian scopes. Just get a good one. Period.
Thanks,

I found a good 2 channels 50Mhz Hitachi, but first I wanted to check if that cheap Russian one would do; since the price difference is huge. I don't know much about oscilloscopes, but it looks better than those handheld (at least I guess it works on real-time sampling)... doesn't look like it has a trigger function though.

About the probes: if I buy the Hitachi (which I'll probably do) I won't be able to afford a pair of those €25 probes; I'll have no choice but to get a cheap pair from China; at least for the time being.
 

DerStrom8

Joined Feb 20, 2011
2,390
Thanks,

I found a good 2 channels 50Mhz Hitachi, but first I wanted to check if that cheap Russian one would do; since the price difference is huge. I don't know much about oscilloscopes, but it looks better than those handheld (at least I guess it works on real-time sampling)... doesn't look like it has a trigger function though.

About the probes: if I buy the Hitachi (which I'll probably do) I won't be able to afford a pair of those €25 probes; I'll have no choice but to get a cheap pair from China; at least for the time being.
Getting a cheap pair of probes temporarily is better than getting a cheap oscilloscope. There is no contest there whatsoever. Get the Hitachi scope and go for the cheap probes, and then buy better probes when you get the money.

I still recommend an HP or Tektronix scope over a Hitachi, but Hitachi is still a very good company.

Matt
 

Thread Starter

adam555

Joined Aug 17, 2013
858
Excellent, congrats!

May I ask how much you ended up paying for it?
The seller rounded it to £100 (±$150) including P&P. It's not bad, considering I've been all day at it -since most I had on the list ended today- and the good ones (more or less like this one) went between £115 and £150.
 

DerStrom8

Joined Feb 20, 2011
2,390
The seller rounded it to £100 (±$150) including P&P. It's not bad, considering I've been all day at it -since most I had on the list ended today- and the good ones (more or less like this one) went between £115 and £150.
That's definitely a decent price, considering it includes postage.

Enjoy the scope!
 

Thread Starter

adam555

Joined Aug 17, 2013
858
I bought a Beakman 9010 and a 9020 sig generator for less than a hundred bucks delivered. 2 channels , 20 Mhz nice for the money and more than adequate for my electronics knowledge and experience. Check Ebay and Craiglist closely.

Wheelchair Bob
I saw quite a few good ones from the US today on ebay, including a Tektronix that looked pretty good, but the problem were the shipping costs; a minimum of $85 + another $25 in customs. So, I couldn't buy any of those because the charges alone took most of my budget.
 

Thread Starter

adam555

Joined Aug 17, 2013
858
Sorry if these questions sounds stupid... but, why do I need to make sure the probes are good; aren't they just a couple of simple cables?

I've been looking for them on ebay, and I saw they are rated for different frequencies (20Mhz, 50Mhz, 100Mhz, etc.), apart from that, how can I make sure a probe is good -apart from looking at the price-?

And last: why can't I just use one of these?

 

DerStrom8

Joined Feb 20, 2011
2,390
Sorry if these questions sounds stupid... but, why do I need to make sure the probes are good; aren't they just a couple of simple cables?

I've been looking for them on ebay, and I saw they are rated for different frequencies (20Mhz, 50Mhz, 100Mhz, etc.), apart from that, how can I make sure a probe is good -apart from looking at the price-?

And last: why can't I just use one of these?

You could use a BNC-Alligator cable, as shown above, but it is not good at higher frequencies, and is more susceptible to interference. Real scope probes have better shielding and filtering, and they are actual probes, so they can fit into smaller places. If you don't need high accuracy and won't be "probing" high-frequency circuits, you might be able to get away with a couple sets of BNC-Alligator cables, but they're not recommended for serious scope use.
 

Thread Starter

adam555

Joined Aug 17, 2013
858
I just found out that probes have specs like attenuation, capacitance, resistance, rise time, etc -apart from the bandwidth, voltage and operating temperature), and I guess these are what make probes either good or bad. Can anyone please explain what should I go for? I mean: which of those are better when higher or lower, and what is the minimum acceptable value.

Here is an example from a probe on ebay:

  • Attenuation Ration: 1:10.
  • Input Resistance: 1MΩ:10MΩ.
  • Input Capacitance: 1X:85pF-120pF, 10X:18.5pF-22.5pF.
  • Compensation Range:10pF-30pF.
  • Rise Time: <3.5ns
Sorry for asking so many questions about every single thing, but I'm not only looking to buy, but also to learn while I buy these things.
 

bance

Joined Aug 11, 2012
315
You can get a set of probes from here.....

You need to match the input capacitance to your scope, for hobby use the rest is not important....

HTH Steve.
 

bance

Joined Aug 11, 2012
315
I bought something similar for my Leader 20MHZ scope and they work fine....

Try not to worry too much if things aren't exactly right, use what you have or can get easily, especially when learning. it's more important to learn than make things perfect....

Steve.
 

Thread Starter

adam555

Joined Aug 17, 2013
858
You need to match the input capacitance to your scope, for hobby use the rest is not important....

HTH Steve.
Just looked at the scope's specs, and this is all it says
Input impedance: 1MΩ//25pF
Are those 25pF the input capacitance? If so, would a probe with this specs do?
Input Capacitance: 1X:85pF-120pF, 10X:18.5pF-22.5pF.
 

Thread Starter

adam555

Joined Aug 17, 2013
858
I bought something similar for my Leader 20MHZ scope and they work fine....

Try not to worry too much if things aren't exactly right, use what you have or can get easily, especially when learning. it's more important to learn than make things perfect....

Steve.
I agree... I was just trying to learn a bit more.
 
Top