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1
METEX DG scope 20 MHz, this is a product designed at about 1995 and product release was at 1997~1998.
I did came across of one this sold as new ( but this is discontinued product , unsold stock ) in one Greek  electronics e-shop.
 
METEX DG scope 20 MHz, this was one product helping mostly in verification of problems when repairing color TV of 90s.
Such DSO today it is considered as good for museums.

Software option for it this is also a dead end,  windows software was available in two floppy discs.
PC Connectivity was made by RS-232 cable and port communication was possible at very slow Bawd-rate.

Bellow it is attached METEX DG scope 20 MHz service manual.

Here is a link from Russia (product pictures and PC software)  METEX DG scope 20 MHz  Windows Software
 
2
Handheld multimeter / NP15 True RMS multimeter - who makes it ?
« Last post by Kiriakos GR on April 12, 2018, 06:42:25 PM »
NP15 True RMS multimeter this is re-branded product.

Possible Descriptions:
a)  NP15 True RMS multimeter 
b)  DMM 601 Series
c)  RISHABH 6016

Original distributor appears to be Rishabh Instruments Pvt. Ltd. (INDIA)

History : In the Summer of 2010, Rishabh Instruments Pvt. Ltd. acquired “Lumel” S.A, a company based in Zielona Gora, Poland. 
Therefore  Lumel this is  Rishabh (INDIA) now using Poland as European marketing channel.

ITTSB Blog comments:
Several brands today trying to demonstrate rich products portfolio and they play the game of OEM, in the case of Rishabh DMM these are probably KOREAN R&D.
User manual this is missing essential information's as for example measurements per second specification.

Old and slow DMM=  2~3 times per second.
Good performance DMM = 5 times
Higher performance DMM = 7 times or more.

Another product series distributed by Rishabh Instruments this is old product line of Gossen Metrawatt, new name this is Rishmulti series.

http://rishabh.co.in/index.php/products/index/0/13

No I am not going to pass any positive recommendation at any product distributed by Rishabh Instruments Pvt. Ltd. (INDIA).
Most of their NEW product series they are known as 12 years old technology.
3
In my case I did ordered one larger panel meter and due sellers mistake I received one LF-109-004-V1 PCB type volt meter.

By 99% you have searched and find this topic because third connection point this be marked as voltage input at your PCB,  this is not working in any way.
Yes this is the manufacturing scam  :)

From today you must freely assume that when you are buying such a meter with three soldered wires, then V-In this would work.
LF-109-004-V1 PCB which I got this has two soldered wires and this also belongs to the crippled ones ( three wires function this is disabled.)

 
Now feel free reading true electrical specifications of  LF-109-004-V1 so to not destroy it.
Practically this meter it is not recommended at applications of bench top power supply, but it is usable for 12V & 24V applications ( battery charger) or other.


Product description
Small-sized open-frame (built-in) digital voltmeter of constant voltage

The measurement range is 3 - 32 V.
At a voltage of up to 9.99 V, two digits after the decimal point are displayed, and more than one is displayed.
The power supply of the device is from the source of the measured voltage.

The device has a built-in stabilizer, but it must be taken into account that even a short-term voltage rise of 30 V this can disable it.  ???

Characteristics:
Type Digital
Type of measured voltage: DC (constant)
Units of measurement: Volt
Measuring range: DC 2.50 to 32.0V (lower than 4.5V, the brightness will be weaker, but this will not affect the measurement accuracy)
Accuracy: +/- 1.0 (%)
Update rate: 200.0 (ms / times)
Display: three digits 0.36 "
Dimensions: 21.5x13x8 mm


 
4
This is a huge surprise even for me.  :)
Within 2012 a Belarus brand started reproduction of old product design of FLUKE 8010 bench top multimeter.

Zavod SVT brand this is located at Belarus Minsk.
Company description : More than 30 years Unitary enterprise “Zavod SVT” specializes the development and production of sophisticated measuring tools, radio-electronic, radiometric and dosimetric instruments for various purposes, as well as special-purpose products for military industry.

ITTSB Blog comments:
This does not look as some sort of a copycat case, latest this is multimeter B7-58 which it does comes with certificates’ from the state of Belarus (Metrology organization).
B7-58 Multimeter gained it certification in 2012 and since then Zavod SVT brand, this still aiming local and Russian market.
 

Known weak point of older 8010 & 8020 Fluke bench top DMM, this is no other than liquid crystal display.
Specific part this is no more available anywhere in the West or Asian world.
What it does requiring investigation this is the possibility if Zavod SVT brand other than manufacturer he is also a spare parts supplier?


http://zsvt.by/index.php/prod/universal/v7-58-58-2#
5
This is actually one presentation of pictures demonstrating internal battery pack formation of battery pack marketed as:
1) Black & Decker 12 V Univolt
2) Dewalt dw9050

Specific battery belongs to Black & Decker 12V Proline series of rechargeable drill.

The owner of this tool purchases it at the year 1992 and nowadays mid of 2018 he asked me If I can open it about examining the possibility of battery pack repair.

Specific battery pack assembly this is worst from all I have seen in my life, in the regard of opening it and reuse it.
Either way I did succeed at opening this battery box and now I feel proud of my self.  :)

Next step this is internal battery cells to be replaced and then I will reseal it in a way that reopening in the future this would be also possible.
6
Handheld multimeter / 2018 - Multimeter Repairability Score ?
« Last post by Kiriakos GR on March 21, 2018, 10:49:06 PM »
This topic it is here mostly about feeding you with thoughts which they will help you back, prior making your next buying decision regarding multimeter.

In past six years ITTSB blog this delivered lots of product reviews, and a huge amount of applications examples these be almost as live demonstration of what modern DMM can do and of how they should be used.
And all such content this is now hosted at ITTSB Blog forum, and because of that fact, many visitors even today they confuse this content with anonymous electronics repair forums, and they send me emails about helping them in their repairs, something which I do not do.

Multimeter Repairability Score as phrase in past years it was meaningless for us working with electronics repairs.
Especially in past decades, repair of your own multimeter this made by thru-hole electronic parts, it was your obligation to fix it back in case that it was damaged due careless handling.

While recent electronics parts technology this improved and it did shirked down electronics components size, component level repair this is still possible but not always.

Respectable brand names which manufacture real multimeter, they use branded microcontroller and input protection electronic parts, and also following specific principals (engineering) regarding printed circuit board (PCB).
Such modern made multimeter it has over-voltage protection at ohms range and possibly in to other measuring ranges, and this new protection makes such multimeter be almost immune to damage.


From the other hand 100% of cheaply sold multimeter, these are prone to damage and not repairable most of times.
Unfinished chip construction this serving as microcontroller, at environmental temperature differences (cold – warm –cold – warm changes) and even due mechanical vibrations,  such unfinished chip this is prone to die due simple insertion of atmospheric air ( oxygen) in it.
At unfinished chip construction what are missing this is outer protective cell, and also proper leads for soldering over PCB.
In the name of ultimate profitability the product that you receiving similes to tuna fish can, this coming also with sort expiration date. 

In conclusion,
There is no Multimeter Repairability Score at cheap multimeter, unfinished chip construction this is mainly the source of Evil, such poor methods was previously used exclusively from anonymous factories in China, but who would thought that American based DMM manufacturer would also use this method at their own low-end products’ line.
Respectable brands from Japan, Taiwan and even in Europe, all are in denial using such poor manufacturing methods.
Therefore next time that you will come close to a buying decision, you should consider that a tuna fish can this is always cheaper, than a true multimeter which will serve you for one or two decades, or more.

7
Update :  Since June 8, 2017 and up to date I am measuring nine months of silence. plus 12 days.
In all this time frame RIGOL news wall stays empty and opinion of ITTSB Blog no matter level of raised voice, this is now considered as well made and an sincere estimation.   

 
8
Few years ago ITTSB Blog has the opportunity to write an in depth product review about DE-208A that is a product aiming professionally working audience.

While DE-208A it is superior as measuring device and build quality among safety both are at high standards, what seemed as negative this was the price point.

Back then it seems that management of DER EE co., Taiwan, it did receive wrong advice due their own marketing team, of what international consumers’ was willing to pay for it.
In the beginning, pricing expectation about DE-208A this was to placed at 400 USD price range, overall  performance of this multimeter this is very close to FLUKE 87V.
DE-208A comes with two additional advantages that FLUKE 87V does not have:
a)   mV range this measuring with precision from single millivolt , so this to support external AC/DC current clamp probe. Such an advantage helps DE-208A to be considered as essential (first choice) multimeter and for audio applications.  At 2018 FLUKE 87V this is now an old meter, limited to electrical applications, when DE-208A this is still a multipurpose multimeter.     

b)     Second advantage, this is data logging capability due USB cable.  Such feature was mainly an advantage introduced from Agilent (Keysight) U1272A. 


Now it makes sense that DER EE co., Taiwan, by thinking that their DE-208A this is one product standing between FLUKE 87V and Keysight U1272A, that this can also stand at that price range.
We are now four years later, and DER EE co., Taiwan it did realize their mistake.
Latest pricing equalization this is at about 150 Euro as retail price for DE-208A.
Such a move this is now an opportunity for DE-208A this to win market share and appreciation from the technical community.
 

DE-208A under the microscope:

a)   Very advanced electronics (speed – precision – bandwidth)
b)   Range switch design (Made in Japan)
c)   High quality banana plug inputs & safety standards for EU & US
d)   Multimeter body this has layer of rubber material (equal product design to U1272A).
e)   And finally only it front mask cover of the LCD display this seems as poor choice of materials in my eyes even today.
f)   But when DE-208A this is offered at 150 Euro and below, I am ready to accepts this product as good over all choice even if aesthetics this is not it strong point.


In conclusion,   
Within 2018 four brand names are dominant in the market of modern and well made multimeter for professional use.
And these are HIOKI (Japan), Keysight U1272A, BRYMEN (Taiwan) and DER EE (Taiwan).
It is unfortunate that other brands with small or larger brand reputation, does not shown identical bravery at equalizing the price of their offerings, neither they care to offer products with updated features in a market that always moves ahead and this now changes more rabidly than ever.

Speaking of signs of innovation, HIOKI invested more thought recently so their high quality handheld multimeter DT4282, this to deliver more in the area of electric vehicles, with AC/DC volts measurement (high speed) and both values are displayed simultaneously.
U1272A this is also capable of AC/DC volts measurement but at much slower display update speed.

For latest pricing and availability you need to contact DEREE website, they do accepts PayPal.
Another option this is offerings due eBay.
I am simply informing of latest news, final purchase decision this is always your own.
DER EE/ DE-208A multimeter Review – By the eye of the Industrial electrician.
9
Product design flaw spotted from one owner of DSOX1102G and a video shown on YouTube.

Symptom: 24V regular transformer output this measured with significant error by switching from DC to AC coupling.
ACV-rms measurement shown more than 10 % error even in comparison with a rms multimeter.

Keysight justified this flaw by their R&D saying:
AC coupling is useful for view waveforms with large DC offsets. 
AC coupling places a 10 Hz high-pass filter in series with the input waveform and removes  DC offset voltage from the waveform.  Keep in mind that 10 Hz is the filter’s -3dB point (and still has some attenuation).
AC coupling should only be used on sine waves greater than 100 Hz and square waves greater than 200 Hz. DC coupling should be used on frequencies lower than that.
So, it's basically a filtering thing when using AC coupling.


ITTSB Blog ....
I did run identical test at my (GW Instek)  GDS-2000A and there is no such measuring unbalance.
7V RMS  at 50Hz  was produced by an AWG generator.
I did double Verification by using regular probe at times X1 & x10 and also by using  single high-performance 50 Ohms cable with BNC plugs.

I wanted to explore if impedance mismatch this can be held responsible in any way.

If you do using Keysight 1000X scope or 2000X or 3000X,  you better check how it performs, because caused error in electrical measurements this could be huge.
Keysight marketing team in past five years it does ignores professionally working electricians bloggers, therefore too bad for them.


 
10
Το 1988 τελευταία μου χρονιά ως ηλεκτρολόγος στο θρανίο,  ρώτησα τον καθηγητή, γιατί δεν μας παρέχουν πληροφόρηση πάνω στα νέα ψηφιακά όργανα μετρήσεων? 
Μου απάντησε ότι αυτά θα τα μάθατε έξω από εδώ.

Αυτό που τεχνηέντως μου απόκρυψε είναι ότι εάν δεν αγοράσεις από μονός σου τεχνολογία αιχμής, δεν θα μπορέσεις να αποκτήσεις γνώσεις και εμπειρίες που θα σε βοηθήσουν να ακολουθήσεις τις τεχνολογικές εξελίξεις η ακόμα και να πρωταγωνιστήσεις στην επαγγελματική σου εξέλιξη. 

Εάν υπήρχε κάποιος άλλος πρωτοπόρος  τις περασμένες δεκαετίες να στήσει ένα  ITTSB Blog,  θα του ήμουν ευγνώμων και υποστηριχτής του.
Βέβαια ποτέ δεν είναι αργά ώστε να πολεμηθεί η ηττοπάθεια, η αδιαφορία και η αμάθεια, και λογικό είναι να μοιράζομαι την ηθική ικανοποίηση της προόδου που έχει επιτευχθεί με την σημαία του ITTSB Blog, με όλους τους συμπαραστάτες και συνεργάτες μου,  οι οποίοι βοηθώντας εμένα, βοηθούν χιλιάδες νέους και τον τεχνικό κόσμο γενικότερα ώστε να ενημερωθούν και να συγχρονιστούν με την πορεία των εξελίξεων.
Τα στατιστικά επισκεπτών του Blog  για έξη συνεχή χρόνια αποδεικνύουν ότι σε επίπεδο χωρών, οι Έλληνες είναι ο δεύτερος σημαντικός όγκος επισκεπτών, μετά την Αμερική.                 


Σαν σήμερα γιορτάζω την απόκτηση του πρώτου μου παλμογράφου για επαγγελματική χρήση, τον οποίο παρέλαβα το 2013.   

https://www.ittsb.eu/forum/index.php?topic=449.0   
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