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Test Equipment / Re: Philips PM3585 PF8629 Custom Disassembler
« Last post by TAMHAN on Today at 08:13:35 am »
Just had an idea. Hit these bastards up:
http://www.helmut-singer.de/stock/1468056088.html
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Will Linux run normal software designed for Windows or does it demand its own programs to run it? I f Ave always fancied playing around with it but been put off by the prospect of having to replace all my software?

From mobile device so predictive text might have struck again

I've always liked the idea of running a linux machine but every time I've installed it I eventually wreck it trying to install stuff (usually drivers for some weird hardware), and then spent too many hours trying to recover it. Lack of knowledge on my part for sure, but linux is quite unforgiving to the newbie and you can be left clueless how to proceed. Dual-boot or a live USB version is not a practical solution (for me), and I don't have the space to dedicate to a separate PC.

If you're an experienced Windows user then simply replacing your OS with Linux and expecting to carry on where you left off is unlikely to lead to happiness. Personally I found it totally frustrating. The GUI interface is nice but don't be fooled by that because sooner or later it's going to break and then you're going to be sucked into command lines and detailed structure of how Linux works. There is no alternative to that learning process, your pretty GUI is unlikely to satisfy all your needs on its own.

However, I found a nice way of getting into it - a lowly RaspberryPi. I installed Ubuntu on it and it takes up very little space on my desk - even with its own dedicated monitor. It's cheap to buy, surprisingly powerful, not overly complex (by being burdened with perpherals), yet contains all the essential ingredients of a running system to learn on. My main Windows PC runs alongside providing access to tutorials and so on. The knowledge gained is transferrable to a more powerful computer.

3
Repair / Re: DSO150 Rotary Encoder.
« Last post by SirAlucard on Today at 08:08:46 am »
However, this one looks like a match:

https://www.ebay.com/itm/401475259389

But I don't see a US source for it.

For $5.60 it'd be cheaper just getting a replacement board and encoder.
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Beginners / Re: Brass wool + flux??
« Last post by KL27x on Today at 08:08:38 am »
Quote
I've tried the commercial stuff & it doesn't seem to work any better than supermarket brass wool, or Stainless steel scrubber pads, for that matter!
The hardness of Stainless doesn't seem to be a problem, at least, I've never seen any great wear on tips from it.

I've found the hardness of the stainless steel doesn't matter. It's the stiffness. If you use the finer stuff, like 000 or higher, it should be fine. The coarser wool is rigid enough to accelerate chipping/cracking of the edge of the chrome plating. The thicker wool concentrates more force into smaller areas, enough to potentially damage the chrome.

It sounds stupid, but there's a similar phenomenon when removing rust from blued carbon steel. If you use 00 steel wool, you remove the bluing. If you use 0000, you can remove just the rust.

Yeah, you can buy bronze wool, commonly sold in marine supply shops and whatnot. If I had to take a guess, I would think it's used to scrub fiberglass. It's super, super fine. There are also some pure copper scrubbers called Chore Boys, but there are a lot of knockoffs that are copper plated steel, too.
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General Chat / Re: Unicode
« Last post by wraper on Today at 08:07:33 am »
I see. And what about electronic engineers who actually design stuff? Should they be able to read basic english?
Because that is what I intended to ask.
If it is Russian engineer who is designing military stuff, I perfectly see having no issue without a knowledge of English. In any case, I've seen many (actually most) fairly intelligent people there who either don't know English at all or know very poorly.
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Eagle / Re: Eagle 9 - any thoughts?
« Last post by rachaelp on Today at 08:06:50 am »
https://forums.autodesk.com/t5/eagle-forum/some-custom-ulps-do-not-work-anymore-after-installing-version-8/td-p/7626803

Yeah that was ages ago and it wasn’t ULP broken it was passing the part involved in a right click context menu custom entry to ULP as a group so you could access it with ingroup(). It was a minor issue which they fixed almost immediately.

How about looking instead at all the positive things they’ve done? Fusion360 integration, SPICE built right in to the schematic editor, Live DRC, Push and Shove, Manufacturing preview, in v9 the design manager makes a huge difference, the new rip up modes in the rip tool make it much more powerful, in the schematic the new bus functionality and the component breakout features make working with busses much more slick. I had a ULP previously to do proper bus management but the new built in feature does away with that. There’s an awful lot of really positive things happening to EAGLE if you take the time to look. Yes there are bugs, and yes there have been stability issues but they tend to fix most of them quite quickly when they are found in the minor number point releases which are bug fix only releases.

Best Regards,

Rachael
7
Metrology / Re: Nortel Trimble NTGS50AA-08: Help needed
« Last post by Zermalmer on Today at 08:05:10 am »
Is it usefull/make sense to desolder the OCXO and make a 'manual' measurement about voltages, current and frequency output depending on the input?
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Metrology / Re: T.C. measurements on precision resistors
« Last post by Andreas on Today at 08:02:54 am »
Hello,

sorry your wording is difficult to understand at least for me as a non native speaker.
I never could imagine that you really want me to take my precious hobby time to grab out all the data.
Up to now you cry for data without telling what you really want to do.

I want to find the form of the polynomial.

Now with the pictures I get the image that you want to solve a problem that is long solved on my side
every time I draw a LMS curve it is actually a 3rd order polynom.
2nd order does not fit in all cases and 5th order usually does not improve the result.

What you have provided in the overview and the CSV file version  is an approximation based on an assumption that the T.C. is a straight line. 

No, the 25 deg C value is actually the linear (1 st order) coefficient of the 3rd order polynominal.
Interestingly the 2nd order coefficient is around 0.032 +/- 10..15% on this batch of the PTF56 resistors.
So the 25 deg C value is a good measure for the fitting.

Once I have the correct polynomial form I can generate a random set of resistors and determine how many measurements are needed  to calculate the change in the voltage of a divider over a specified temperature range.  This is an afternoon's work if I have your actual measurements.
you are loosing yourself in a dream world in generating artificial data.
Reality will differ: in the PPM range you have to treat every resistor as a individual.

Edit:  I digitized a few points from 10k#8.

attached the normalized result of 1 minute averages of deviation from 25 deg C value (in ppm) over temperature difference to 25 deg C in (deg C)
(ignore the first 3 lines they are only the instruction for my solver).

good luck

Andreas

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Buy/Sell/Wanted / Re: [Wanted, AU] Cheap, basic scope
« Last post by vk6zgo on Today at 08:02:53 am »
Check out Hamfests in your area.

There are often older Oscilloscopes for sale amongst the Ham rigs & stuff.
The prices are usually quite reasonable.

It is, of course, like in the "Rivers" ad----"There may be many, or there may be none."
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Repair / Re: DSO150 Rotary Encoder.
« Last post by SirAlucard on Today at 08:01:50 am »
I did take mine apart, and one of the pins are misaligned. I was able to get it from just not working, to only slightly working. I really don't have enough knowledge on it to be able to realign it properly. It ended up melting out of place when I went to desolder it out and swap it around for a battery mod.
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