China equipment

[Ralph Mowery]

There is a lot of items comming from China now. Some seems ok and some
not. Ran across this about the companies making two versions. One using
low quality parts and another using higher quality parts for venders
that want a better quality produit at a highe price.

Any truth to this or just advertising ?

https://www.circuitspecialists.com/blog/our_hantek_oscilloscopes_are_fab
ricated_using_higher_level_components/

[Jeff Liebermann]

If you read the above page, it says
"...with a 'less expensive' power supply and 'less expensive' LCD."
I would assume that implies that the rest of the electronics are the
same in both versions.

Power supplies come in all shapes and sizes. Some are beefy, can
handle overloads, can handle the heat heat, respond faster, etc and
are generally better and more expensive. LCD's come in various
technologies, which offer different features and performance. For
example, viewing angle on the cheap TN displays might be quite narrow,
while the pricy IPS displays can approach 180 degrees. Also important
is response time, which is 5msec or less on good displays, but longer
on cheaper slow displays which will tend to show streaks on moving
images. Hantek might also be juggling the dot resolution on the LCD,
where the cheaper display has fewer dots resulting in a rough looking
image.

LCD panel types:
<https://pcmonitors.info/articles/lcd-panel-types-explored/>

Although not found in test equipment, TV and computah LCD display
types can go even higher end:
<http://www.pchardwarehelp.com/guides/lcd-panel-types.php>

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Bob Engelhardt]

On 9/4/2016 11:37 AM, Ralph Mowery wrote:
>...
> https://www.circuitspecialists.com/blog/our_hantek_oscilloscopes_are_fab
> ricated_using_higher_level_components/
>

Also on their site is the "Mooshimeter" - a DMM that Bluetooths to a
smart phone with an app that does computing and text or graphic display.
Cool?

https://www.youtube.com/watch?v=ow9LHVuod9Q

[ohg...@gmail.com]

The only way to tell for sure is to buy one from Circuit Specialists and one through Alibaba or ebay based on price, then compare them.

I have no information one way or the other, but years ago when manufacturers made product for specific buying groups, they would distinguish any variances with a unique model number, or at the very least a suffix code or letter. Samsung in fact used to add a single letter on the same line but a bit away from the model number that would show which LCD display was installed. An "S" after the model number would indicate a Samsung display and a C would indicate a Chungwah (can't recall the exact name) display.

But since Hantek is based in China, all bets are off.

[Micky]

On Sun, 04 Sep 2016 09:35:22 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>On Sun, 4 Sep 2016 11:37:29 -0400, Ralph Mowery
><rmower...@earthlink.net> wrote:
>
>>There is a lot of items comming from China now. Some seems ok and some
>>not. Ran across this about the companies making two versions. One using
>>low quality parts and another using higher quality parts for venders
>>that want a better quality produit at a highe price.
>>
>>Any truth to this or just advertising ?
>>https://www.circuitspecialists.com/blog/our_hantek_oscilloscopes_are_fabricated_using_higher_level_components/
>
>If you read the above page, it says
> "...with a 'less expensive' power supply and 'less expensive' LCD."
>I would assume that implies that the rest of the electronics are the
>same in both versions.

"Unfortunately, Hantek does not distinguish between their products by
using different part numbers. However, when we order Hantek
oscilloscopes, we always specify that they are to supply us with the
upgraded versions."

I've been doing that for a long time.

At a restaurant, I always tell them I want prime grade beef.

When I buy a car, I tell the salesman, Give me a good one.

And at restaurants I always say that I want a clean glass.

I wonder if this method works.

[Ralph Mowery]

In article <3pstsb5ginpn8q49h...@4ax.com>,
NONONObobb...@gmail.com says...

>
>
>
> "Unfortunately, Hantek does not distinguish between their products by
> using different part numbers. However, when we order Hantek
> oscilloscopes, we always specify that they are to supply us with the
> upgraded versions."
>
>

Hantek does seem to have an INT or International after the part number
on some of their scopes. This is suspose to be the upgraded parts if
the advertisment is correct. I have not seen any scopes in person,so do
not know if all of them inported to the US are that way or not, or if
they even make any at all that do not have that International after the
part number.

As just a hobby user I can not justify an expensive scope,but did put a
DSO 5202P on order today from Circuit Specilies. This will be my first
storage scope. The one that I have been using is a Tectronics 465b 100
mhz analog scope. Just thought a storage scope wold be nice to play
with for around $ 300.

[Jeff Liebermann]

On Tue, 6 Sep 2016 14:16:24 -0400, Ralph Mowery
<rmower...@earthlink.net> wrote:

>As just a hobby user I can not justify an expensive scope,but did put a
>DSO 5202P on order today from Circuit Specilies.

Argh, too late. You could have bought the cheaper Hantek model, which
can be hacked to provide 200MHz bandwidth and additional features:
<http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/msg264085/#msg264085>
<http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/>

[pf...@aol.com]

On Sunday, September 4, 2016 at 11:37:26 AM UTC-4, Ralph Mowery wrote:

> There is a lot of items comming from China now. Some seems ok and some
> not.

I have never felt either the need or the inclination to purchase any electronics from China for my hobby, or on which I might depend. Full stop.

Peter Wieck
Melrose Park, PA

[JW]

On Tue, 6 Sep 2016 11:48:06 -0700 (PDT) "pf...@aol.com" <pf...@aol.com>
wrote in Message id:
<55a7c411-08d7-41e3...@googlegroups.com>:

I got to say +1 on that, but I make my living with such gear. I'll only
trust equipment from first tier T&M manufacturers. Tek,
Keysight/Agilent/HP, Keithley, Fluke, etc. Don't have time for the bugs.

[Ralph Mowery]

In article <5c3usb11rmm66cako...@4ax.com>,
je...@cruzio.com says...

>
> On Tue, 6 Sep 2016 14:16:24 -0400, Ralph Mowery
> <rmower...@earthlink.net> wrote:
>
> >As just a hobby user I can not justify an expensive scope,but did put a
> >DSO 5202P on order today from Circuit Specilies.
>
> Argh, too late. You could have bought the cheaper Hantek model, which
> can be hacked to provide 200MHz bandwidth and additional features:
> <http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/msg264085/#msg264085>
> <http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/>

I have either seen that or something similar. Sometimes the components
may not be up to the faster speed in the slower scopes. I did see one
place where one of the scopes needed a capacitor changed or removed.

Can't prove it, but just thinking that they may do the chips like the
old compuer chips. They would test them for speed and mark them for the
maximum speed they could run without making errors.


I did buy a function generator a while back that went to 25 MHz with the
sine waves. The faster square waves did not look too good but there was
a modification to change about 10 parts to bring the waveform more up
to speed.

[Ralph Mowery]

In article <q27usbl6n0ldsnvir...@4ax.com>, no...@dev.null
says...

If I made my living I would have the high quality equipment. I did work
as an instrument technician for a large company and we bought the beter
quality test equipment and much of it was calibrated by a lab that
certified it to the NIST, or what ever it is called every year or so.

I do have some older HP and Tectronic and Fluke test equipment. It is
just hard to justify paying several thousand dollars when $ 300 will
tell me all or more than I need to know.

I look at it like the Harbor Freigh stuff. For something that may be
used just a few times, much of that will get the job done. Say a hammer.
They may use soft metel and the hammer will mushroom after a few hits,
but if all yo want to do with it is drive in a few tent posts a couple
of times a year it is worth it just to have that hammer in the box with
the tent.

[Jeff Liebermann]

On Tue, 6 Sep 2016 16:53:28 -0400, Ralph Mowery

<rmower...@earthlink.net> wrote:

>In article <5c3usb11rmm66cako...@4ax.com>,
>je...@cruzio.com says...
>>
>> On Tue, 6 Sep 2016 14:16:24 -0400, Ralph Mowery
>> <rmower...@earthlink.net> wrote:
>>
>> >As just a hobby user I can not justify an expensive scope,but did put a
>> >DSO 5202P on order today from Circuit Specilies.
>>
>> Argh, too late. You could have bought the cheaper Hantek model, which
>> can be hacked to provide 200MHz bandwidth and additional features:
>> <http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/msg264085/#msg264085>
>> <http://www.eevblog.com/forum/testgear/hantek-tekway-dso-hack-get-200mhz-bw-for-free/>

>I have either seen that or something similar. Sometimes the components
>may not be up to the faster speed in the slower scopes. I did see one
>place where one of the scopes needed a capacitor changed or removed.
>
>Can't prove it, but just thinking that they may do the chips like the
>old compuer chips. They would test them for speed and mark them for the
>maximum speed they could run without making errors.

Nope. What they do is build them all to 200 MHz, and then reduce the
bandwidth and remove features to accommodate those that don't want to
spend as much money. I only know of one scope that has been modified
in this manner. It was a Rigol something and it worked perfectly.
Anyway, the EEVBLOG thread is rather long and has 2834 replies over
the last 6 years. If there were any problems encountered doing the
modification, I'm sure they would have appeared somewhere in the
thread. I didn't read all 2834 replies, but in skimming, I found a
few where some of the features didn't quite work as expected, but
except for one person who had problems using decent parts, the reports
were generally positive.

Too late to change your order?

>I did buy a function generator a while back that went to 25 MHz with the
>sine waves. The faster square waves did not look too good but there was
>a modification to change about 10 parts to bring the waveform more up
>to speed.

The square wave has all the odd order harmonics of the fundamental
sine wave. Much depends on the corner frequency of the output low
pass filter. In general, the filter will need to pass everything up
to the 5th or 7th harmonic to looks like a square wave. In a function
generator, the low pass is not really necessary, but helps if there is
some digital junk that might leak into the output amplifier. It might
also be there to keep the FCC happy, but since I've never type
certified a function generator, I don't know if that's really
necessary.