Oscilloscope

[WM6]

For free from mains power supply lowers:

There are really interesting tablet alike, battery powered, touch screen, portable scopes on market.

I wish to present two of such models of different brands, that offer great measurement possibilities,
which anyone can read by himself on given links, but this time with one warning remark.

Warning remark refers to scope technical parameter named Vertical sensitivity or Y sensitivity.

For us who wanted to observe small signals, oscilloscope vertical sensitivity is of high importance.

Let see two example (both Chinese brand):

Fist one of (main?) brand FNIRSI and sold under different brand names, here under name DANIU ADS1013D

https://www.banggood.com/DANIU-ADS10...r_warehouse=CN

Best Vertical sensitivity of this scope is at its best 50mV/div.


Second one is newest model of known Micsig tablet scope serie named Micsig STO1104C

https://www.banggood.com/Micsig-STO1...r_warehouse=CN

Vertical sensitivity of this scope is at its best 500uV/div (or 0.5mV/div).


So we have two scopes, not really in same price and quality range, but we are here mainly interested in
Vertical sensitivity.

Regarding that: if price range of two scopes is in ratio 1:4, then sensitivity range is in stunning ratio 1:100.

What this mean in our weak signal measurement practice?
It means, that once we are able comfortably to observe weak signals and
in other cases, we can face with no visible signal at all.

To explain this graphically.
We take same 2mVpp signal on two scopes, one with best Vertical sensitivity of 1mV/div and
other with best Vertical sensitivity of 50mV/div.

This is how our weak signal of 1mVpp look like on those two scopes:
(so it is reason to be attentive to Vertical sensitivity data at scope buy)

[ivconic]

Miscig looks sharp and pretty cool!

[WM6]

10 tips for buying new oscilloscope:

From Tektronix:

https://www.mouser.com/pdfDocs/10-fa...illoscopes.pdf

From Agilent:

https://studylib.net/doc/18242469/te...t-oscilloscope

[Matt_Rowe]

Thanks, checking out the links you posted

[Matt_Rowe]

Ok, how about voltage input, and sampling rate, i have read that we can use the 1X or 10X probe i guess to add more voltage, how about the sampling rate, would this be decent of a unit .
Trying to read up on sampling rate, ect to understand and i think ive got it,its better to have the sampling rate as high as i can afford and be on both channels and not split.
Now, how about voltage, is it real important.
Hantek Oscilloscope

[waltr]

Ok, how about voltage input, and sampling rate, i have read that we can use the 1X or 10X probe i guess to add more voltage, how about the sampling rate, would this be decent of a unit .
Trying to read up on sampling rate, ect to understand and i think ive got it,its better to have the sampling rate as high as i can afford and be on both channels and not split.
Now, how about voltage, is it real important.
Hantek Oscilloscope

Did you notice it claims 110mhz (milli-Hz) bandwidth whereas in the Manual's Spec it is 100MHz (Mega-Hz).

Here is the Manual:
https://www.electronicaembajadores.c...000_series.pdf

Checking details....in Tech Specs.
100Ms/s not 1Gs/s

Voltage is 10V/div with 10x probe.

Voltage is the last spec I consider when buying. Only when actually measuring do I consider Voltage to ensure I do not Kill an input.

When building my PI detector I simply used a resistor Voltage divider (80:1) to ensure the Coil fly-back Voltage would not hurt my scope.

Overall that scope looks ok for hobby use even with the typos and minimal specs.

Biggest issue may be- does it work out of the box and if not how easy it get a replacement.
This is a 'Chinese' scope which can be hit or miss.

So ensure you buy it from a place that will replace it or at lease take a return.

[Matt_Rowe]

Thanks again waltr, i didnt think about looking at the manual,great point to check that the title is telling the truth, its on amazon.
Yes its chinese, but i was also comparing to ebay scopes of the crt type, and name brand, but again, no warranty,ect, and they mostly say it powers on,ya right, anything can power on.
I was looking at ones where they had the probe hooked up to the test spot and actually had a square wave that looked close to where their dials where set.At least i know they tested the unit some what, because they had a picture of it in the listing.
Ill keep looking, craigslist might be best because i could test before i buy
Thanks again, ill go look at manual you posted

[WM6]

Ok, how about voltage input, , i have read that we can use the 1X or 10X probe i guess to add more voltage,
Now, how about voltage, is it real important.

Not really important parameter. All your requirements to voltage input limitations are easy resolved
by using 1x, 10x or (good to have) 100x probe attenuation.
Of course you need to know where and why to use which of mentioned probes. By rule: bigger expected
input voltage, ask for probe with bigger factor (say: when you measure 666V pulse, start with 100X probe
or at least with 10X probe - depending of V input limitation).

Ok, how about sampling rate, Trying to read up on sampling rate, ect to understand and i think ive got it,
its better to have the sampling rate as high as i can afford and be on both channels and not split.

One of most important digital scope parameters. Here you need to ask for: "Real sample rate".
Today in $200 to $300 digital scope price range Real sample rate per channel should not be less than 1Gs/s

In price range of your link above, independent (non split to two or more channels) 1Gs/s is practically non existent.

But according producer, by buying this scope you get "two time base systems" as great support to sampling rate:
https://www.banggood.com/UNI-T-UTD21...r_warehouse=CZ

High Sampling rate is "conditio sine qua non" when you ask for as much as possible true presentation of
analog signal on digital storage oscilloscope.

Even more if you ask for true presentation of complex signal wave forms or single short signal events.
Even more if you ask for true presentation of different modulated signals.

Even cheap analog scope is able to better handle modulated signals than 10X more expensive $3000
Digital scope units.

So don't go lower than 1Gs/s per channel with your new digital scope.

[waltr]

I use at home an older 2ch analog scope, a BK Precision 2120B with 30MHz BW.
For building analog metal detectors, both PI & VLF this works well.

It is only when I work on digital (micro-controller based) circuits that I wish I had a digital scope to capture and hold a serial data, clk, etc. I tend to be able to muddle through and get things working and if really stuck take it into work to use a digital scope.

[WM6]

True.

But digital scopes are "in" and fancy with its display scanning functionality, PC transfer and data processing, memories, FFT etc.

No matter of digital commodity and functional capacity I will never parted from my two analogs units.

[Matt_Rowe]

Thanks for the replies, right now price is one concern and if they will work for a metal detector build is second, here is another one, pc based, quite a few videos on you tube of setup, use, ect, lots of people have bought these and pretty good reviews on amazon and you tube,
I juist found one on craigslist also, older analog, 2 channel, crt, waiting on seller to answer a few questions though.
Kikusui Dss5020A craigslist $50.

Hantek oscilloscope Amazon

[surfdetector]

Thanks for the replies, right now price is one concern and if they will work for a metal detector build is second, here is another one, pc based, quite a few videos on you tube of setup, use, ect, lots of people have bought these and pretty good reviews on amazon and you tube,
I juist found one on craigslist also, older analog, 2 channel, crt, waiting on seller to answer a few questions though.
Kikusui Dss5020A craigslist $50.

Hantek oscilloscope Amazon

Here is a link to the user manual for the Kikusi if you don't already have it.
https://manual.kikusui.co.jp/D/DSS5020A_E.pdf

Don't forget to take a set of probes with you if you go to check it out as it doesn't look as though they are included with the scope.
Cheers

[Matt_Rowe]

Thanks, surfdetector, i will have to because he said he doesnt have any, but said it works, so i asked him again how does he know it works without having any probes.He said it worked last time he used it, so i asked him again, how did you use it without probes, still waiting on answer. He has a few pics of it on, straight line on top left side, and then another straight line on bottom right.
thanks for your response and help, i will go look at the link and manual.
Thats a big difference WM6 in the pics you attached above.

[Matt_Rowe]

kikuso oscilloscope from craigslist

It does say in the pdf that surfdetector posted
Norm 5 Mv/div-5v/ div
X5 MAG:1mv/div-1v /div

And input voltage--400 vpeak {dc plus ac peak} ac: peak 1khz or lower
polarity change channel 2 only
Max sampling speed 1m samples/sec

[WM6]

Norm 5 Mv/div-5v/ div
X5 MAG:1mv/div-1v /div

This is OK (if scope is in OK working condition - not to heavy used)

Max sampling speed 1m samples/sec

This is hybrid CRT scope.

It can work in classic analog way as real time CRT oscilloscope with 20MHz bandwidth

or

as digital storage oscilloscope with 1Ms/s (max) and <300kHz bandwidth.
Digital storage mode of scope work is pretty poor by today's standard (it is dedicated to
audio field and at the same time sufficient for MD lab needs).


In general it is/was OK scope, all depend on how you are able to check its
present working condition on remote way.