Test Equipment Anonymous (TEA) group therapy thread

[mansaxel]

mnem
At least the trains will run on time...

                

Der war gut!

German DB is really far away from being good to be "on-time"        

It's SBB CFF FFS (I don't remember if there's a Romansh acronym too) who are good at keeping time. Good luck getting the swiss to invade you.

[radiolistener]

Yeah, not since they showed up on Dave's bench; typical now is $350-400. Now on CLEARANCE for $300 +S/H at TEquip. From the video this one appears to have much more linear output re: voltage vs frequency. Rigol still has yet to address this with FW even in the more expensive models, to my knowledge. Plus this one is rated 300MS/s vs 125MS/s for the Rigol.

mnem
 

PSG9080 at 163$ US on Ali: https://www.aliexpress.com/item/1005001507207074.html?spm=a2g0o.productlist.0.0.20bc53b9tnKOqc&algo_pvid=624891f7-d70e-4a59-8347-265f64056dc6&algo_expid=624891f7-d70e-4a59-8347-265f64056dc6-0&btsid=0bb0624616012220981132182e5bf8&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

I guess it's not a bad price.

I got this unit for testing. So if you have questions I can help.

The first thing I noticed in Scott's (Defpom) teardown was the SMPS powering it. 
Really, who wants one of those powering your signal source ? 

yes, it suffers from SMPS noise. But the main SMPS is not a problem, because you can power it from external linear PSU. But it uses DC/DC on the main board to generate bipolar ±15 V from 5V. This DC/DC sits there, even if you power it from a low noise linear PSU.

This noise is low, but unfortunately you can hear it if you put generator output on the AM receiver input (through attenuator). So, if you planning to use it for AM modulation to transmit music on AM receiver, you're needs to be ready that you will hear some SMPS noise in background.

If you don't need low noise source, it works good.

Look like output impedance is fix at 50 . On the Rigol you can set that manually and it will automatically adjust amplitude based on selected output impedance. I often use that feature.

Yes, it use 50 Ohm output. I tested output impedance for different amplitude range and it is very close to 50 Ohm.

Regarding to Rigol and Siglent, as I know they actually use the same 50 Ohm output, the setting on UI affects just displayed value.

who says linearity is better on the Juntek than Rigol ? you found a comparison somewhere ?

at a glance amplitude looks very stable up to 50-60 MHz. Above that it starts to drop.

Really I want a nice signal generator that has a wide band source, ALC and then a stepped attenuator rather than this arrangement but it’ll do for now. (Siglent that is). I might build one. They aren’t that difficult to put together.

ALC is good for sine wave, but I think it will be impossible to use it for arbitrary wave signal.

[mansaxel]

German trains and public transport ? Umm, no thanks, the train stations have turned into a no go area starting 2015.
Way too much risk to:

<snip list of sensationalist issues>

This is not my experience with Germany. The main reason I've been late on Die Bahn has been permanent way maintenance.

The facts in the case is that, globally, the amount of deaths from anything else than high age and associated complications have been decreasing steadily for decades.

Some groups find facets of the society we live in inconvenient and not as beneficial to them as they feel they're members of a formerly more privileged group, and therefore promote a discourse where everything is allegedly going to hell, usually because <other kind of people>.

In reality, I'm more nervous about:

* Fascist terrorism to promote above,

* Organised crime largely being proliferated from artificially creating barriers-to-entry into society by the better off, (but they largely kill each other, the problem is that police get too much rights to oppress people because gummints want to be seen as tough on crime. A better way would be to make sure their children get a better school and some guidance and help to make them see there is something else than the gangs.)

* The rise of nationalistic thug governments "to combat the moral problems of today". (which is an organised mode of #1)

[bd139]

Nailed it, particularly that last three.

Just been party to a large and scary piece of RF test gear. Philips Achieva MR scanner . My middle one had a routine scan to check something out. It's Sunday, 13:00, straight in, scan, straight out, £0. Parking was £3.50 though 

[Specmaster]

Nailed it, particularly that last three.

Just been party to a large and scary piece of RF test gear. Philips Achieva MR scanner . My middle one had a routine scan to check something out. It's Sunday, 13:00, straight in, scan, straight out, £0. Parking was £3.50 though 

Its disgusting charging parking at a hospital, people do not go to hospitals normally out of choice for fun do they. They go to either visit a sick relative or friend or to receive some medical attention at an outpatients dept or similar. My own local hospital has a dedicated car park for the A&E dept. when going there it can so often be fairly urgent and lets face it, paying for pay and display ticket  is the very last thing on your mind then, its immoral.   

[bd139]

Yeah exactly. On top of that the two shops in there are M&S and WH Smith which are rip off merchants.

[Specmaster]

Totally agree, although the M&S in our hospital does carry a far larger range of sandwiches compared to the city centre store, I suppose they are milking the patients who are mobile and want something different to hospital food 

[bd139]

Yeah anything is better than hospital food. They had steak on the menu once. I should have known better. Was made of cat I think 

[mnementh]

Yeah, not since they showed up on Dave's bench; typical now is $350-400. Now on CLEARANCE for $300 +S/H at TEquip. From the video this one appears to have much more linear output re: voltage vs frequency. Rigol still has yet to address this with FW even in the more expensive models, to my knowledge. Plus this one is rated 300MS/s vs 125MS/s for the Rigol.

mnem
 

PSG9080 at 163$ US on Ali: https://www.aliexpress.com/item/1005001507207074.html?spm=a2g0o.productlist.0.0.20bc53b9tnKOqc&algo_pvid=624891f7-d70e-4a59-8347-265f64056dc6&algo_expid=624891f7-d70e-4a59-8347-265f64056dc6-0&btsid=0bb0624616012220981132182e5bf8&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

I guess it's not a bad price.

I got this unit for testing. So if you have questions I can help.

The first thing I noticed in Scott's (Defpom) teardown was the SMPS powering it. 
Really, who wants one of those powering your signal source ? 

yes, it suffers from SMPS noise. But the main SMPS is not a problem, because you can power it from external linear PSU. But it uses DC/DC on the main board to generate bipolar ±15 V from 5V. This DC/DC sits there, even if you power it from a low noise linear PSU.

This noise is low, but unfortunately you can hear it if you put generator output on the AM receiver input (through attenuator). So, if you planning to use it for AM modulation to transmit music on AM receiver, you're needs to be ready that you will hear some SMPS noise in background.

If you don't need low noise source, it works good.

Look like output impedance is fix at 50 . On the Rigol you can set that manually and it will automatically adjust amplitude based on selected output impedance. I often use that feature.

Yes, it use 50 Ohm output. I tested output impedance for different amplitude range and it is very close to 50 Ohm.

Regarding to Rigol and Siglent, as I know they actually use the same 50 Ohm output, the setting on UI affects just displayed value.

who says linearity is better on the Juntek than Rigol ? you found a comparison somewhere ?

at a glance amplitude looks very stable up to 50-60 MHz. Above that it starts to drop.

Really I want a nice signal generator that has a wide band source, ALC and then a stepped attenuator rather than this arrangement but it’ll do for now. (Siglent that is). I might build one. They aren’t that difficult to put together.

ALC is good for sine wave, but I think it will be impossible to use it for arbitrary wave signal.

Thanks for the brief, concise rundown of the pros & cons of this unit. That was pretty much the gist of what I'd pieced together myself after reading multiple threads on eevBlog. Also, I've had that very listing on my RADAR for a few months now; I just have other priorities ATM. Like this 4070A.

mnem

[vk6zgo]

Yeah anything is better than hospital food. They had steak on the menu once. I should have known better. Was made of cat I think 

When I had my "pretend knee" fitted, the food at the hospital in Armadale WA was pretty good.

They also had a place you could buy all sorts of cakes, savoury rolls, decent coffee, & so on, if you could stagger down there.
The car park was pretty scary, though-- -----it is built on the side of a hill, & walking up from the only spots left, right at the bottom, was a bit rough on a wonky knee!

[Cerebus]

Some groups find facets of the society we live in inconvenient and not as beneficial to them as they feel they're members of a formerly more privileged group, and therefore promote a discourse where everything is allegedly going to hell, usually because <other kind of people>.

You're forgetting to include the "things were better when we were children" effect. Every generation has done this as they get older, looked on their youth through rose tinted glasses. I've seen it with my grandparents generation and my parents generation. Nowadays, of course, things really are worse than in my youth. Why, I was going to the shops the other day and there was this bunch of young layabouts standing on a street corner. As I walked past them... [Cont'd p 73]

[mnementh]

Is Q2 C to E shorted?

It's going to be something like that. Not much different to the output stages on TTi stuff.

I'd load the output with 50 ohms and then work back up the signal chain from the output until you get a signal that isn't sick.

Naaahhh... I already checked the obvious stuffs: MCP at output tests good with junction tester, no obviously shorted diodes, relays or tants (this thing is peppered with the little black ones, but all being run minimum of 10V below rated) in my original post before I even started searching for tech ref.

My money is on the AD811ANs; they're being run at +/- 15.5V on a 15V nominal/18V max rated part. They also have heat-sinks made from hand-cut scraps of U-channel bonded to the chip with silicone sealant; hardly the best choice for thermal conductivity.

My personal suspicion is that this unit was one of the dregs... the last few mainboards bought from Berkeley Nucleonics... whipped out with whatever they had in the lab that didn't require any cash outlay in an effort to stave off the creditors for another quarter.

Given all the other sins committed therein, and where they tapped into for +5V to run the thing (that requires a pretty intimate knowledge of the mainboard, as it is not an obvious first choice) off one of the solder pads for the RESET button, I wouldn't be surprised if the 30mm-fan-in-a-40mm-hole came out of the B&K Labs that way too. 

That said... I think I'm going to step away from the bench for a afternoon... spend some time widda wife & kidzz. Bondene to fix my 54645A should be here soon, and I want to have my scope back in one piece before I go poking around this thing's innards. Using it nekkit to do triage on this thing was enough taunting Murphy for one project.

mnem
Everything is a learning opportunity.

[Saskia]

well, they tried to mug my hubby at the Ingelheim train station, they were 3, he was alone.

In Frankfurt they tossed kids onto the tracks when there was a train incoming.

We have several knife attacks a day in the Rhein Main area.

I was threatened because I was not wearing a Nikab (why the hell should I ?)

I am not so certain if that is something that we should welcome as a positive change for society.

But let us not dive into that.

Sick today, flu-like symptoms. Spending the day resting, mostly in bed and see how it goes.

[Specmaster]

One from the "How the hell could that happen" dept, maybe thats the kind of thing that happens when you have a national network but not run and overseen by a national body. So much for privatization in the name of making a quick profit eh?

[Cerebus]

Yeah anything is better than hospital food. They had steak on the menu once. I should have known better. Was made of cat I think 

One of the advantages of living where I do in London is the huge Asian population. It means that the local hospital has to cater for their dietary requirements, which means that there's always a good selection of 'curry' on the menu (It may even be locally produced). The 'ethnic' selection is always edible, sometimes even good; which I can't say about the 'British' side of the menu.

I suspect that when they first were forced by demographics to deal with the fact that a lot of Indians will only eat vegetarian food, and that another lot of Indians will only eat Halal, they probably did the usual half-arsed job and turned out terrible food. Then the hospital catering manager had to face a deputation of 'Aunties' of the inpatients. Since then the catering hasn't looked back, and the catering manager is still trembling. 

If you have the misfortune to land up in a hospital bed and it's at Newham General Hospital, always opt for the 'curry'.

[mnementh]

My stomach just quivered... not sure if it was the mention of curry (and not Tim Curry ) or the mention of the assembled aunties. 

mnem
*twitch... twitch... twitcha-twitch...*

[Saskia]

I hope to get my Carolina Reapers soon. Nature's antibiotics should defeat a stupid virus as well (by raising body temperature high enough that the virus is cooked ...)

[Cerebus]

Late 2nd breakfast:

[mansaxel]

Late 2nd breakfast:

Ahh, nice!

Myself, I woke up rather early after a somewhat unconfortable night in a bunk bed. Scouts and guides (we're co-ed) outing. We ran out of porridge for breakfast. Probably because we asked how many would want some and made just enough. When I got into the kitchen, coffee was already made. Not a bad morning, all in all.

smoke-smelling

[tonyalbus]

VA meter for schools... repair
Lucas Nulle



They are just huge!

[mnementh]

On a Sunday...? 

mnem
 

[mnementh]

Late 2nd breakfast:

fuck you.

mnem
very cordially, of course.

[Cerebus]

Aw, c'mon Mnem. It's only a little bit of flour, sugar and egg with soft and crispy layers separated with creamy French butter. No need to go overboard about it. 

[bd139]

You forgot the agonising labour bit 

[Cerebus]

I have to do something to get off my fat, lazy butt. It might as well be directed at something I can later enjoy while sitting on my fat, lazy butt.