Advice on affordable USB oscilloscope

[[ Frank ]]

I'm an hobbist and I'd like to purchase an affordable - but decent - USB
oscilloscope. What do you think about the following product?

http://po.labs.googlepages.com/usbosciloskop

Thanks in advance

 

[Anthony Fremont]

[ Frank ] wrote:

I'm an hobbist and I'd like to purchase an affordable - but decent -
USB oscilloscope. What do you think about the following product?

http://po.labs.googlepages.com/usbosciloskop

Thanks in advance

Honestly, I think the 200kHz sample rate is wayyyyyy toooo slow. ;-) I
think that if you look around, you can find yourself a nice chinese DSO for
about twice the money. Something like this maybe:
http://cgi.ebay.co.uk/RIGOL-DIGITAL-Oscilloscope-DS1022C-25MHZ-COLOUR-LCD_W0QQitemZ260092438586QQcategoryZ45008QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I just bought the DS1102C and I really like it. Believe me it blows that
USB scope away with 400 million samples per second and a 1MB buffer depth.
Plus it comes with a 3 year warranty.

 

[[ Frank ]]

Anthony Fremont ha scritto:

I just bought the DS1102C and I really like it.

It's 445¤ (the version including 16channel Logic Analyzer)
Anyway, seems a very good instruments.
Thanks

 

[Anthony Fremont]

[ Frank ] wrote:

Anthony Fremont ha scritto:

I just bought the DS1102C and I really like it.

It's 445¤ (the version including 16channel Logic Analyzer)
Anyway, seems a very good instruments.
Thanks

The logic analyzer adds allot to the price at least on the model that I
bought. It added 50% to the price, so I didn't get that option.
These are fairly inexpensive, but I don't know anything about them:
http://cgi.ebay.co.uk/OWON-PORTABAL-DIGITAL-Oscilloscope-EDU5022M-25MHZ-COLOR_W0QQitemZ260091740224QQcategoryZ45008QQtcZphotoQQcmdZViewItem

Larger screen and battery options, lower sampling rate, but still miles
ahead of the USB scope. I went with the Rigol because they make one of
Agilent's low-end scopes and I liked the features.

 

[John E.]

Larger screen and battery options, lower sampling rate, but still miles
ahead of the USB scope. I went with the Rigol because they make one of
Agilent's low-end scopes and I liked the features.

Description says:
---
400 MSa/s maximum real-time sample rate and 25 GSa/s maximum equivalent
sample rate
---
Can you explain to the less-knowledgeable how is 400MS = 25GS?

Thanks,
--
John English

 

[Terran Melconian]

On 2007-03-21, John E <incognito@yahoo.com> wrote:

400 MSa/s maximum real-time sample rate and 25 GSa/s maximum equivalent
sample rate
---
Can you explain to the less-knowledgeable how is 400MS = 25GS?

They sample it over multiple cycles and combine them. If the signal
isn't repeating identically it doesn't work. "equivalent sample rate"
is a BS spec; if I *had* a repeating signal I would be using the analog
scope anyway. My advice is to ignore it and pay attention to the 400.

 

[Anthony Fremont]

Terran Melconian wrote:

On 2007-03-21, John E <incognito@yahoo.com> wrote:
400 MSa/s maximum real-time sample rate and 25 GSa/s maximum
equivalent sample rate
---
Can you explain to the less-knowledgeable how is 400MS = 25GS?

They sample it over multiple cycles and combine them. If the signal
isn't repeating identically it doesn't work. "equivalent sample rate"
is a BS spec; if I *had* a repeating signal I would be using the
analog scope anyway. My advice is to ignore it and pay attention to
the 400.

Exactly.

 

[Lionel]

On Wed, 21 Mar 2007 06:59:41 -0700, John E. <incognito@yahoo.com>
wrote:

Larger screen and battery options, lower sampling rate, but still miles
ahead of the USB scope. I went with the Rigol because they make one of
Agilent's low-end scopes and I liked the features.

Description says:
---
400 MSa/s maximum real-time sample rate and 25 GSa/s maximum equivalent
sample rate
---
Can you explain to the less-knowledgeable how is 400MS = 25GS?

The first figure is for continuous sampling over a time period, & the
second figure is for sampling with skewed timing offsets over multiple
time periods. Eg; it might take 10 samples over one cycle at X+0%,
then another 10 samples from the next cycle at X+5%, etc, resulting in
finer detail, but with the risk of aliasing.

--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
\|/ \|/ Perna condita delenda est
---^----^---------------------------------------------------------------