Improving the analog input

[ldrolez]

Hi !
Do you know how to improve the BW response of the scope ? Better
caps ? Replace the tlo84 with something else ?
Ludo.

[Stevan C.]

As far as I can tell, the "stiff throat" is the capability of the MCU
to process the signal?

What did You see?

cheers!
Stevan C.

[ldrolez]

> What did You see?

I have still not received my scope but in this review,
http://forward.com.au/JyetechOscilliscope/JyetechOscilliscopeReview.html
,
you can see that a 62khz square signal is far from perfect...
I'll make my own tests later

Ludovic.

[JYE oscilloscope]

The critical portion for analog bandwidth is the input capacitance
compensation. The simple probe has larger capacitance too so it will
affect bandwidth a lot. The rest of analog channel is pretty flat to
1MHz based on what we tested.

On 11月24日, 下午10时31分, ldrolez <ldro...@gmail.com> wrote:
> > What did You see?
>

> I have still not received my scope but in this review,http://forward.com.au/JyetechOscilliscope/JyetechOscilliscopeReview.html

[davebr]

That review pretty much reflects what I experience. I find that the 2
uS/Div setting is totally unusable. The bandwidth starts to
deteriorate the leading edge ~20KHz so it is perfectly fine for audio
use which is what I use it for. I find that the maximum usable
frequency is about 100KHz on the 5 uS/Div setting. You can go higher
in frequency but it is harder to view at 5 uS/Div resolution. I'm
looking for general waveform information so the limited bandwidth is
not an issue for me. I know what the artifacts are so I can look past
that. I think it's pretty good performance for an AVR
implementation. The -091 firmware is a big improvement in useability.
Dave

On Nov 24, 6:31 am, ldrolez <ldro...@gmail.com> wrote:
> I have still not received my scope but in this review,http://forward.com.au/JyetechOscilliscope/JyetechOscilliscopeReview.html

> You can see that a 62khz square signal is far from perfect...
>   Ludovic.

[Stevan C.]

Is there a Way to go better than that?
A "quick fix" mod for up to ~200kHz?
:-)

Stevan C.

[Trevor]

Good heavens! I have a 30 year old Philips 100MHz Analog Oscilloscope
which is without peer for HF analog measurements. My more modern HP
54522A digital storage scope is not a patch on the analog scope for
analog use. The JYE digital scope fills another niche altogether, and
IMO analog would be the least effective of its capabilities,
regardless of whether the Nyquist frequency is 2MHz or 20MHz. Have you
seen how the analog input circuits of a real oscilloscope are
manufactured? Tons of shielding and 1% quality components :) Ultra-low
capacitance technologies. Each of my high-impedance probes cost 5
times as much as the whole JYE scope :)

To get a good analog scope requires much more than is apparent on the
surface. Probes which don't load the circuit under test are very
important - for a 10 microsecond pulse the coaxial cable probe of the
JYE looks like almost a short circuit to the device under test :)

..Trevor..

[davebr]

Let me clarify. I can't get any waveform to display on the 2 uS/Div.
It is drawing something but I can't ever get a stable display. On the
5 uS/Div it is quite stable and usable. At greater than 100 KHz on
the 5 uS/Div, the waveform is so dense (e.g. so many cycles) that you
can't really see much information anymore. I think this scope is
great for audio+ range signals which is exactly what I need it for.

Dave

On Nov 26, 3:28 am, "Stevan C." <ces...@gmail.com> wrote:

[JYE oscilloscope]

1us/DIV just works in AUTO mode and trig is not handled because MCU is
too busy. So you need to push OK to get a stable display.

> > A "quick fix" mod for up to ~200kHz?- 隐藏被引用文字 -
>
> - 显示引用的文字 -

[davebr]

Correct. If I put my 10X probe on the oscilloscope and calibrated it
at 1 KHz, I get very nice square edges up to 150 KHz or so which is my
practical limit to resolve on the 5 uS scale. - Dave