Recent Posts

1

Projects, Designs, and Technical Stuff / Re: Low power (<10uA ideal) Ideal diode, up to 13v

« Last post by Tangent_Tracker on Today at 12:41:40 pm »

That looks a good option, I was hoping for something all in one package tbh, but beggar's and choosers and all that!

2

Test Equipment / Re: SDS800X HD Bugs/Wanted Features

« Last post by electronics hobbyist on Today at 12:39:34 pm »

I use persistance not only for visual aid, since you can really do measurements with it! You can measure min and max of a pulse and roughly the average of it.

That may work, but 2N3055's point was that the scope has better ways to do it. If you set up a measurement for pulse height (or duration, depending on what you are after), in advanced measurement mode and with statistics enabled, you will get precise max, min and average values. Plus a histogram of the distribution if you care about that! 

Yes, if better methods can be used to solve the problem, it can save a lot of time, as 2N3055 said, let the machine work for you.

3

Test Equipment / Re: Test Equipment Anonymous (TEA) group therapy thread

« Last post by factory on Today at 12:36:55 pm »

I heard of the custom scale thing. Is that per model or per instrument? How did they do that custom print for every individual meter face cost effectively?

A scale was plotted individually for each meter using a custom calibrator set-up.

The process is described in HP Journal Vol. 12 No. 7 March 1961.

A servo based calibration machine for the older scale plates. But looking at a manual I got out of storage, the 432A manual from 1969, it states they were "individually computer-calibrated", wonder if this was also covered in one of the Journals.

David

4

Repair / Re: HP 3478A: How to read/write cal SRAM

« Last post by radar_macgyver on Today at 12:35:31 pm »

Figure 7-G-5 (03478-66501) is the older schematics.
Figure 6-5 (C3478-66501) is the newer one, with 7402.

So your machine has a newer configuration.

Got it - however, the documentation is still a bit confusing since the schematics show the NOR gates as U515, while the text(and my board) references U508. In the schematic, U508 is a hex inverter.

What kind of U502 you have?
Section 6-25 says that revision D changes it to 28 pin chip.

Mine is a 20-pin DIP.

5

Test Equipment / Re: SDS800X HD Bugs/Wanted Features

« Last post by ebastler on Today at 12:33:34 pm »

I use persistance not only for visual aid, since you can really do measurements with it! You can measure min and max of a pulse and roughly the average of it.

That may work, but 2N3055's point was that the scope has better ways to do it. If you set up a measurement for pulse height (or duration, depending on what you are after), in advanced measurement mode and with statistics enabled, you will get precise max, min and average values. Plus a histogram of the distribution if you care about that! 

6

Buy/Sell/Wanted / Keysight MSOS054A FI/EE

« Last post by BeamDump on Today at 12:31:31 pm »

Hi everyone

I have a Keysight MSOS054A scope that as much as i wanted to find use for, i can't so logical thing would be to sell it to someone that might actually use it. Scope suffered from PLL2 issue but has been repaired. Acquisition board replaced with never version. And calibration done end of Dec 23. Since then scope has been power on once to make video. Physically it's in perfect shape and as is never been used since it left Keysight.

Can see here:
https://youtu.be/G69l9h4mwsg

https://www.upload.ee/image/16529137/1.jpg
https://www.upload.ee/image/16529136/2.jpg


Can come to collect scope to Estonia or Finland, or i can drive it anywhere in the EU my self. It has original box but i won't try to ship, i don't have much reputation and don't wanna be responsible for any shipping mishap. Payment cash on collection or delivery.

I understand this is very specific equipment and most enthusiast have no use or money for it. Some cheaper Chinese tool/clone or diy solution can do similiar for much cheaper. I don't wanna inflate the price, fleebay is doing good job of that already and most equipment sellers here are taking current fleebay prices, instead of following "sold" history.  So, I'm not sure what price should be. Make a suggestion and we'll see i guess.

7

Beginners / Re: Automatic golf ball dispenser

« Last post by xvr on Today at 12:29:57 pm »

If you want to dispense ball by pressing a button than you don't need even Arduino. Button + solenoid + buttery. That is all that you need.

8

General Technical Chat / Re: Migrating as a PHD student to US

« Last post by ebastler on Today at 12:29:52 pm »

I think the main question you need to answer for yourself is whether you want to do a PhD -- independent of any immigration and visa questions. As you and others have said, it's several years of hard, poorly paid work. (Where the payment probably varies quite a bit, depending on the specific university's policies and funding, and potential project funding they get.)

The reward is (a) in the PhD title, which may be beneficial to your future career, whether employed or as an entrepreneur or independent contractor. And also (b) in the freedom to explore, go deep on technical questions, discover or invent something new. If both aspects appeal to you, go for a PhD; if neither does, don't do it. And then, unfortunately, there is a large grey area inbetween where the decision may be a difficult one...

Regarding visa and immigration conditions: It seems that running a self-employed business on the side is possible as a student on an F1 visa; see the link below. Disclaimers: I have no personal experience or expertise in this area at all, and don't know how reliable that source is. And of course you would need to find the time for self-employed work in parallel to a PhD program!

https://www.immigration-america.com/self-employment-options-for-f-1-students

9

Repair / Re: Teardown and repair of a Gossen Metrawatt Metratop 51 (Model M2510) benchtop DMM

« Last post by coromonadalix on Today at 12:22:34 pm »

the MetraTop series come / inspired from the 28s 29s  series,  mostly from their same asic and the resolution at 310,000 counts


as for the price  loll     

My new 28s  costed 30% less than the TOP 51,  but costed a lot  ... with an good import fee  ...  Euro to Cad   outch outch outch

Gossen are a niche and very expensive, even the accessories as i wrote in the past are ridiculously expensive(s)

Metrix are not far away too

i would love to get my hand on a Gossen 30M   .....  anyone  loll

10

Test Equipment / Re: new killer scope in town - a true game changer from R&S - RTB2002 & RTB2004

« Last post by Darkover on Today at 12:22:31 pm »

PMK PML712 are selling 315 Euro plus VAT each...

Aehm..yes. I am using older PML211 on my scope I bought  a few years back. I remember something like 150Euro VAT included.

https://www.batronix.com/versand/messtechnik/tastkoepfe/PMK/PML211.html

It is always possible to exchange bandwith by euro. 

Olaf