Have you used VELLEMAN HPS10 Digital O-scope?

[bearing01]

Hi,
The above mentioned scope is a hand held.

http://www.mbelectronics.com/view.aspx? ... 20HPS10-SE

I am thinking about buying it but before I do I was wondering if anyone out there has used it before. Is this product any good?

[MrAl]

Hello there,

I dont see any bandwidth spec anywhere...one of the most important
specs for a scope of any kind. Usually they at least spec MSPS
(megasamples per second) because this really determines what
you can use the scope for and what you can't.
It says 'for audio' so assume low bandwidth. This means it probably
does not work on anything above audio.
Maybe you can find the true specs on another web site...

[bearing01]

Sorry for not posting the specs. When I made this post I didn't have time to go into more detail.

http://www.designnotes.com/downloads/Os ... erence.pdf

http://www.designnotes.com/downloads/Ma ... _10-UK.pdf



It says max sample rate is 10MS/s and max bandwidth is 2MHz. Therefore, I guess if you want to capture digital waveforms (with nice square edges) you want to sample up to atleast the 9th harmonic. Therefore, that limits the max digital waveform frequency to probably something like 500 kHz? Using Tektronix the rule of thumb suggests 2MHz/5 = 400kHz.

It also says it has memory length like 256 Bytes. What the hell is that? Sounds like if you're sampling at 1kS/s you would collect samples for 256ms. That is, you could see 1 period of a 3.9Hz waveform. This can't be right. Could someone set me straight? If it was this low then what's the point of having the memory capture function at all!


I know this scope would be quite a step down if you're used to using a 1GS/s Tektronix scope. I have a 100MHz analog scope. I was tinking about getting this little one for automotive measurements and some low speed digital.

Still wondering if anyone has used this scope and whether or not they like it.

------
For info on understanding digital O-scope specs:
http://www.tektronix.com/Measurement/cg ... illoscopes

[bearing01]

It also says it has memory length like 256 Bytes. What the hell is that? Sounds like if you're sampling at 1kS/s you would collect samples for 256ms. That is, you could see 1 period of a 3.9Hz waveform.

I wrote this and didn't think about it. After I left the computer I realized that 3.9Hz is the slowest waveform that can be captured by 256ms of data. You would capture 2 periods of a 7.8Hz or 20 periods of a 78Hz waveform.

[MrAl]

Hi again,

I wouldnt count on this thing working for anything but audio
(up to 20kHz). Note also the "real time" sample rate.
If you've got 1MHz sample rate that divided by 5 gives you
200kHz, but do you really want to see a 200kHz waveform
represented by only 5 dots? I know i dont
On the other hand, at 20kHz you've got 50 dots, or 25 dots
per half cycle...that's not too bad unless you are looking for
distortion (which you probably should use a distortion meter
for though).

If you are used to a 100MHz scope there is no way you are
going to like this thing, unless of course you are workng on
audio or line frequency stuff.

Even so, i think you are doing the right thing in looking for someone
else who has used one of these things, as long as they dont work
for the company

Is there any way you can try it out and if you dont like it be able
to return it for full refund?

I have two Velleman meters, and i can tell you they are not that bad,
but then again they are not that good either