Test Equipment Anonymous (TEA) group therapy thread

[BU508A]

Hello,

today my Rohde & Schwarz ADS Dual Arbitrary Function Generator arrived. Packaging was so lala, the generator was fully wrapped with 3 layers of thin bubble wrap. This was putted in a huge sturdy box with lots of this paper wool all around so it couldn't move.


I powered it on first, because I was curious about its functionality.

This is it in action:


All the knobs and the wheel are working well, the BNC connectors are looking good. Nice detail: there is a very fine mesh over the VFD's to prevent any RF leakage. 

I did some testing. First, I was interested in how the sine is looking in the frequency area (FFT). The ADS can do a max. sine frequency of 5 MHz. I set the output to 1V_p-p and then I found out, that I don't have any decent 50 Ohms BNC terminators.  (The plan was to visit this year the HAM Radio in Friedrichshafen to get some, but ...) Will try to find some in the bay, together with some T-adapters.

This is the result for 5MHz, on the left is Ch1, on the right Ch2:


I had the impression that Ch2 is slightly better than Ch1.

The second test was feeding Ch1 and Ch2 into the scope and run it in XY mode to check the phase coupling between both channels.

This is the result for a sine wave, 1.6V_p-p at 500kHz and +90° for Ch2. Looking good. Amplitudes are okay, too.


Then I increased the frequency to 5MHz and now we can see a little divergence in the phase. The generator is still saying +90° but the XY plot disagrees. I've reduced then the phase to 87° and voilà, a perfect circle. I have to check the data sheet if this is okay or not. I think it is not.

On the left it is set to 90°, on the right to 87°.


And here just for fun I did  a XY plot with the triangle function. Not really convinced about the linearity.
Settings: 500kHz, 1.6V_p-p, Ch2 +90°


Teardown will follow, stay tuned.

Edit: typos

[tautech]

I set the output to 1V_p-p and then I found out, that I don't have any decent 50 Ohms BNC terminators. 

No 50ohm internal termination ?

And here just for fun I did  a XY plot with the triangle function. Not really convinced about the linearity.
Settings: 500kHz, 0.8V_p-p, Ch2 +90°

Yeah looks nothing flash but maybe it's your terminations or cabling. 
You need find out which.

[BU508A]

No, the RTB 2004 has only 1MOhm||19pF, no 50Ohm termination.
And yes, I thought of the cabling and the wrong termination, too.
As soon as I have some proper T-adapters and BNC terminators I'll
repeat this measuring again.

[tautech]

No, the RTB 2004 has only 1MOhm||19pF, no 50Ohm termination.
And yes, I thought of the cabling and the wrong termination, too.
As soon as I have some proper T-adapters and BNC terminators I'll repeat this measuring again.

Ah, OK.
Later might come back with screenshots of how good...or not, a triangle is from a SDG6022X as maybe some data point to compare against.
Busy now.

[mnementh]

On the bench tonight: Back-to-school presents for the boy.



The Elegoo (yes, really  ) electro-bits kit was ~$15; it comes with a breadboard, PSU PCB for the breadboard, jumper kits and pretty much all the components needed for the first few chapters of the book. One of the first projects involves abusing a pot and deliberately toasting a LED... I like the way this guy thinks. 

mnem
Start 'em young. 

[Specmaster]

On the bench tonight: Back-to-school presents for the boy.



The Elegoo (yes, really  ) electro-bits kit was ~$15; it comes with a breadboard, PSU PCB for the breadboard, jumper kits and pretty much all the components needed for the first few chapters of the book. One of the first projects involves abusing a pot and deliberately toasting a LED... I like the way this guy thinks. 

mnem
Start 'em young. 

That looks so interesting, I hope he likes electronics, lucky boy.

[wolfy007]

curve tracer voltage / current loop design. Currently uncompensated so this will no doubt oscillate like a wild monkey masturbating



sw1 sets voltage or current steps. sw2 sets step size.

Edit: looking at bias currents and stuff I’m going to have to add range switching for current sense for micro amp ranges. This gets really complicated really quickly. Need to build something that scales from 1uA to 10mA with better than 5% accuracy, universal stability under load level changes and a fair compliance range 

I doubt a 741 can be used to measure high-side current; instrumentation amps are traditional, but ISTR there's an opamp with a ridiculously high input voltage spec (i.e. >>supply voltage) that can be used for this.

Will you need a negative supply?

If you need a higher voltage output, consider this circuit ...


FFI, see the current "High Voltage op amp" thread in s.e.d

It's fairly low voltage there as it's step generator only. All under 15V. I've got an INA series instrumentation amp somewhere with built in laser trimmed precision resistors which is getting substituted in when i find it. Bias current and offset are major issues rather than voltage on that bit. This has to source / sink a max of 100mA (for version 1 anyway) with about 5v of compliance or voltage steps up to 10V.

The high voltage supply is much simpler and is just a simple voltage controlled voltage regulator driven from 0-5v in and 0-200v out with a BU508A or similar on it. Only needs to source current fortunately so nothing fancy required!

Edit: place your bets. Broken or not broken? Hameg HM605:

Ive found the Hamegs to be quite reliable and hardy, Im voting for working!

PS: OK just saw the later post, hooray for working (despite dodgy packing)!

[Zoli]

And now, for a change, something different:
Last week, I saved two cardboard boxes from the dumpster; as good cardboard boxes do, they followed me home, and presented model for pictures.

For those lazy to look it up - these are laser based distance sensors; range:0.05-500m; accuracy:±1mm+0.05mm/m above 30m; resolution: 0.1mm; tracking: up to 250Hz(max 7m/s).
I hope soon to present some terminal screenshots from these bad guys...

[capt bullshot]

TEA for non-electrical measures 

[Fungus]

Watch this , guy's a legend lol

Note that he says nothing when a cyclist does the exact same thing:

https://youtu.be/lGkYM_PE2DA?t=16

[bd139]

On the bench tonight: Back-to-school presents for the boy.



The Elegoo (yes, really  ) electro-bits kit was ~$15; it comes with a breadboard, PSU PCB for the breadboard, jumper kits and pretty much all the components needed for the first few chapters of the book. One of the first projects involves abusing a pot and deliberately toasting a LED... I like the way this guy thinks. 

mnem
Start 'em young. 

That’s a win. It’s the modern equivalent of the radio shack 160-in-1 I got that started all this 

[Specmaster]

Radio Shack have a lot to answer for then

[bd139]

Hahaha 

Actually to be honest it was a guy who used to work for the local education authority around where I lived at the time. He was responsible for developing the science curriculum and took that opportunity to piss around with Lego, electronics and Acorn computers all day. He was mostly responsible for the BBC Micro and Lego in schools in the 1980s. My father was friends with him so I got to spend a day in his “lab” circa ‘82. About ten years after that he was made redundant when they centralised everything, his wife left him, moved to the US, bought a Trans AM and decided to retire by running a party boat full of floozies. Guy was a fucking legend. No idea if he’s still alive or not now.

[BU508A]

Hahaha 

Actually to be honest it was a guy who used to work for the local education authority around where I lived at the time. He was responsible for developing the science curriculum and took that opportunity to piss around with Lego, electronics and Acorn computers all day. He was mostly responsible for the BBC Micro and Lego in schools in the 1980s. My father was friends with him so I got to spend a day in his “lab” circa ‘82. About ten years after that he was made redundant when they centralised everything, his wife left him, moved to the US, bought a Trans AM and decided to retire by running a party boat full of floozies. Guy was a fucking legend. No idea if he’s still alive or not now.

First, I thought this is some kind of a flea circus, then I checked at LEO the meaning of it.
Learnt something new today.   

[McBryce]

On the bench tonight: Back-to-school presents for the boy.



The Elegoo (yes, really  ) electro-bits kit was ~$15; it comes with a breadboard, PSU PCB for the breadboard, jumper kits and pretty much all the components needed for the first few chapters of the book. One of the first projects involves abusing a pot and deliberately toasting a LED... I like the way this guy thinks. 

mnem
Start 'em young. 

Lesson 1: No breadboard EVER looks that neat when you've finished wiring the circuit!

McBryce.

[mansaxel]

Lesson 1: No breadboard EVER looks that neat when you've finished wiring the circuit!

Mine always looks like a shrubbery. If it does work and is stable there, it'll work most everywhere.

[med6753]

Hahaha 

Actually to be honest it was a guy who used to work for the local education authority around where I lived at the time. He was responsible for developing the science curriculum and took that opportunity to piss around with Lego, electronics and Acorn computers all day. He was mostly responsible for the BBC Micro and Lego in schools in the 1980s. My father was friends with him so I got to spend a day in his “lab” circa ‘82. About ten years after that he was made redundant when they centralised everything, his wife left him, moved to the US, bought a Trans AM and decided to retire by running a party boat full of floozies. Guy was a fucking legend. No idea if he’s still alive or not now.

If he is no longer with us I'm sure he went out with a smile on his face. 

[McBryce]

Lesson 1: No breadboard EVER looks that neat when you've finished wiring the circuit!

Mine always looks like a shrubbery. If it does work and is stable there, it'll work most everywhere.

McBryce.

[med6753]

So the Lady Copper's 11 year old Dell tower joined the great gig in the sky. Obviously it's my job to fix that. The only thing she ever uses a computer is to browse the internet. Or occasionally print something, from the internet. For that type of user Winblows seems like overkill. Decided that Linux would be the best solution for her. I have a Dell tower here with Mint on it but I'm not happy with that distro. It sucks. Slow to boot and overall just clunky. Also have a Toshiba laptop with Ubuntu 19. It boots fast and seems overall snappy. But it seems every time you boot it wants to load updates. But at least it's a pain free update process.

So....gonna take the Dell tower and wipe Mint and load Ubuntu. Show her how to use it and be a hero. 
 

[BU508A]

So the Lady Copper's 11 year old Dell tower joined the great gig in the sky. Obviously it's my job to fix that. The only thing she ever uses a computer is to browse the internet. Or occasionally print something, from the internet. For that type of user Winblows seems like overkill. Decided that Linux would be the best solution for her. I have a Dell tower here with Mint on it but I'm not happy with that distro. It sucks. Slow to boot and overall just clunky. Also have a Toshiba laptop with Ubuntu 19. It boots fast and seems overall snappy. But it seems every time you boot it wants to load updates. But at least it's a pain free update process.

So....gonna take the Dell tower and wipe Mint and load Ubuntu. Show her how to use it and be a hero. 
 

For updating my Ubuntu machines I'm running once a day under root:

apt-get update; apt-get -y dist-upgrade; apt-get -y autoremove

No "Klicki-Bunti" stuff

[tautech]

No, the RTB 2004 has only 1MOhm||19pF, no 50Ohm termination.
And yes, I thought of the cabling and the wrong termination, too.
As soon as I have some proper T-adapters and BNC terminators I'll repeat this measuring again.

Ah, OK.
Later might come back with screenshots of how good...or not, a triangle is from a SDG6022X as maybe some data point to compare against.
Busy now.

Busy day so had to wait until after dinner.

SDG6022X with BU508A's settings although for a perfect XY box AWG needed a 45^o phase setting.
SDS2104X Plus internal 50ohm termination and settings to mostly fill the XY box.
As attached.

[med6753]

So the Lady Copper's 11 year old Dell tower joined the great gig in the sky. Obviously it's my job to fix that. The only thing she ever uses a computer is to browse the internet. Or occasionally print something, from the internet. For that type of user Winblows seems like overkill. Decided that Linux would be the best solution for her. I have a Dell tower here with Mint on it but I'm not happy with that distro. It sucks. Slow to boot and overall just clunky. Also have a Toshiba laptop with Ubuntu 19. It boots fast and seems overall snappy. But it seems every time you boot it wants to load updates. But at least it's a pain free update process.

So....gonna take the Dell tower and wipe Mint and load Ubuntu. Show her how to use it and be a hero. 
 

For updating my Ubuntu machines I'm running once a day under root:

apt-get update; apt-get -y dist-upgrade; apt-get -y autoremove

No "Klicki-Bunti" stuff

I noticed that Ubuntu 20 was just released. Are there any major changes from 19?

[BU508A]

I noticed that Ubuntu 20 was just released. Are there any major changes from 19?

I don't think so. 20.04 is a LTS version, perhaps a good idea to install this one (5 year support)
They have removed the Amazon Weblauncher and added some other stuff e.g. Wireguard VPN.

Details can be found here.

[Saskia]

it seems they now have "snap" stuff anywhere,
https://www.howtogeek.com/670084/what-you-need-to-know-about-snaps-on-ubuntu-20.04/

and that got on my nerves big time.
So that I installed a debian on a RockPi 4 which is what hubby is using for his internet stuff.
Works, does not need many updates, and is fast enough and generally good enough for this kind of application.

I could never grok that snap stuff and removed Ubuntu 20 from my system.

[bd139]

Snaps are a fucking pile of shit.

Seriously windows 10 plus all the linux stuff in VMs is about as close to sanity as I can get.