Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

Dusty Springfield... now there's a blast from the past. 
mnem

If we are going to get sentimental and nostalgic about the 60s, here's a picture that inexorably makes people think of the song in the video.

[BU508A]

I am tempted to replace the "C" with a "J" in the Coke ad.

 

Those neon signs reminded me of this video:

[khs]

I took one semester of calculus in 1972, worked my tail off .....

That reminds me of my first encounter with calculus in my senior year of high school.  Boy, did I go to town!  I could wrangle all sorts of integrals and differentiation was a doddle.  Sat down to the final exam and there was ONE question on the subject that I could have answered after a few lessons.  I felt cheated!

Then I hit the wall with some charming exercises on matrices - something I had barely touched on.  Fortunately, there was question requiring a 3D geometry proof that I had never encountered before - but it all just fell together for me.  I got a good pass in the subject, but I'm still dirty about the calculus.

... and then promptly forgot everything I learned and never looked back. 

Same.   

Some time ago I met an fellow student - meanwhile a senior scientist at a big aerospace company:
I asked: Do you need more than the four ground numeracy skills?

His answer was "no - but wait - sine and cosine I need too"

Last class reunion I asked a former classmate meanwhile an architect:
Do you need more than the four ground numeracy skills?

His answer was "no - but wait - sine and cosine I need too"
Why I asked back. "Some people want to get skew walls".

So you need ....

[dl6lr]

In my school career, I had some truly terrible professors (the ones that just don't care are worse than the ones that are hard to get on with) and some truly awesome ones. One of the best was one of the math professors who mainly taught really advanced stuff...he is the finest lecturer I've ever had the pleasure of sitting in on, and he was most gregarious with office hours.

Me too. The truly awesome one was a math professor, too. After the "electrical" professor presented his stuff for the whole semester with noone understanding what he was talking about, all became quite clear and understandable after the math prof did one example in about half an hour.

The professor teaching physics was in multitasking. Being asked a question, he answered and simultaneously he drawed something on the board. Then suddenly he stopped speaking, glanced at his paper he was holding in his hand, started talking again, began to wipe out things on the board, stopped talking, glanced at his paper again, wiped something out... Finally he wiped out everything on the board, took his paper and turned it by 180 degrees 

And now for something completely different: New TEA arrival.

[mnementh]

Oooh... you know it's a tricky one when they build the cheat-sheet into the front of the unit... 

mnem
and that one has 3...!

[xrunner]

Assistant prof. in calculus always said "Oh this isn't too hard, all you have to do is use a little "mathematical gamesmanship" to solve it. I'll always remember that. 

[mnementh]

Those neon signs reminded me of this video:

https://youtu.be/sznLJq52SPM

When I was working stained glass with my mom, I dabbled in spun glass and slumped glass bits for her to incorporate into her pieces. I seriously considered getting into neon art and glass-blowing as they both fascinated me, but a few weekends volunteering in a glassblower's shop in King's Bay brought that dream into sharp focus: the shop was hottern'ell, and it needed to be to keep the glass workable and not constantly breaking.

I've been overly sensitive to the heat all my life; I start to get muzzy-headed and headachy at anything above 70-ish F. Gaining all this weight has only made that worse in my old age.

So sadly, I abandoned those dreams as "simply incompatible".

mnem

[Andrew_Debbie]

Dana 5100 update.

The LM311H comparators arrived this morning and I replaced the dead one at lunch.   To my surprise the meter started to work on the 2VDC scale.   I put the digitizer card back and buttoned it up.    I did some quick DCV checks and it worked.






I decided to try my 2.5000V reference and that is when things went sideways.   

Here is a short video. 

https://youtu.be/nkUiT873iIk


Need to get back to work now.  Will continue troubleshooting when I have time.

[xrunner]

Good work. That is a really odd design for a front bezel - it looks upside down to me. 

[Andrew_Debbie]

That is a really odd design for a front bezel - it looks upside down to me. 

I'm not sure what they were thinking.    It does put the panel at a better angle if you have the meter up on the bail on the top of stack of other gear.    If you have it flat on the bench it is ummm non optimal.

It will be entertaining to use this.  If I ever get that far.

[mnementh]

Don't be silly, you can't put neopixels on a pastie, they'd be too crunchy.   

Edit: Bugger! I'm hungry now.

Oooooh.... would you just lookit all those delightful car-bubble-hydrates...

I bet there's 70 grams in there, at least. That's like 5 days' worth...

Growing up in Peesborgh PA, there was a local bakery on the way to and from school that made little pot-pies like this, only as there was a large local concentration of Polocks, the contents were more Slavic-oriented. Lots of shredded pork or beef, potatoes & onions, just enough carrots to add color, and heavy on garlic, salt & basil. Those were a favorite; If I didn't like what was on the lunch menu I'd often just get a snack and chocolate milk, then pick up one or two on my way home.

Or one of those and a little apple pie... *wipes drool from chin*

mnem
no carbs for yooo...!

[Saskia]

apple pie ? which one yer tawkin bout ?
southern style ? (i.e. the liquid version) ?

[mnementh]

mnem
*slurrrrrrp*

[Brumby]

Looks delicious!

Mustn't stare for too long .....  or I'll put on a kilo and double my BSL. 

[med6753]

The 600MHz/50 ohm 7A19 plug-in arrived. Packaging was excellent. Totally encased in bubble wrap plus in a large box filled with peanuts. And plug-in itself is in very good condition. The position control was extremely tight. Some light machine oil on the pot shaft freed it up. A lot of dust inside especially on the attenuator board. Did a quick clean up with IPA and deoxit. It may require removal for an IPA bath. We'll see.

Functional test on the 7904 later.






And in other news. In the past 24 hours this guy has been power cycled from a cold start at least a dozen times. And then allowed to fully warm up. Not once has there been the slightest twitch of any sweep instability. I find it somewhat perplexing that apparently a simple trimmer adjustment fixed it. I'm going to continue this power cycling for the next day and see what happens.

[mansaxel]

More opticks:  Yesterday I got to go through a serious OTDR exercise and fault diagnosis properly for the first time. Time, accurately measured, is a very powerful instrumentation dimension on many things.  The OTDR we've got has a minimum pulse length of 3ns. Very good resolution in short, metro style fiber runs, and quite useful to see details of splices and patch panel interfacings. Me like. It of course costs like serious amounts of money, in the order of 40000€ or so.

[mnementh]

To put that in perspective... our Rav4, with a mid-tier options package (AC, AT, power windows, cruise, etc but no stoopit shit like butt warmers and the like) cost equivalent of ~22000€ new a few years ago.

mnem
needs more cowbell.

[med6753]

OK, initial checkout of the 7A19 plug-in. This plug-in will now allow me to utilize the full 500MHz B/W of the 7904. And yes, the attenutors are a little spotty so I'll have to remove them for a more complete cleaning.

Signal source is the Heath IG-4244 Oscilloscope Calibrator. First up. Easy 10MHz. The ringing on the trailing edge is a normal artifact of the IG-4244. I actually like seeing it. The more ringing observed the higher the B/W of the scope. Scopes 50MHz and below can't display that ringing.



20MHz.



50MHz. I had to switch the 7B80 Time Base over to 10X. I guess I need to purchase a 500MHz 7B92 Time Base plug-in.  And as you can see the IG-4244 is starting to run out of gas.



And finally, 100 MHz. That's the upper limit of the IG-4244. But that plug-in and scope are asking for more but that's the highest signal source I currently have here. Must do more Bay of Evil shopping. 

 

[mansaxel]

And finally, 100 MHz. That's the upper limit of the IG-4244. But that plug-in and scope are asking for more but that's the highest signal source I currently have here. Must do more Bay of Evil shopping. 

Actually, 100MHz square, FSVO square, is when you think of it, a lot of overtones, way beyond the bandwidth of the 7904. I think the poor Heath does a good job.

But yes, a UHF RF signal generator should be on your shopping list. As it is on mine.

[mnementh]

mnem
see you on the other side, buddy.

[med6753]

But yes, a UHF RF signal generator should be on your shopping list. As it is on mine.

Yep. I do have a Heath IG-5280 RF Generator but it's upper limit fundamental is 110MHz.

[capt bullshot]

But yes, a UHF RF signal generator should be on your shopping list. As it is on mine.

There's one of these: http://wunderkis.de/mg3633a/ waiting for a new owner. It's #3 from the repair reports, with the attenuator waiting for a cleaning, just like #1.
It's in not so nice optical shape, but working. It was intended as a reserve unit, but I never need it.
It doesn't reach full output level in the lower frequency range (up to 1.3 or so GHz), and the output level is about 1dB off in this range.
If you're pedantic, let it pass by.

And I can't be bothered to ship it outside EU.

[Vince]

Oh no, forum is ultra slow here again !    Could not load all the Papa Smurf's pics ! Timed out halfway : I could see the top half of the pics, ie the function gen, but not the scope! 


Look what I just got today ! 

Guess what's in the box... winner gets a big cookie with lots of chocolate chips !!
In case Dwagon or Saskia win, sorry for you it's gonna be chicken soup instead ! 

I understand I am asking a bit much here, so I will be nice and give you a hint : #6.

[capt bullshot]

I understand I am asking a bit much here, so I will be nice and give you a hint : #6.

For example I have FIVE type 317 scopes !

So I'd guess it's a 317 

[med6753]

mnem
*slurrrrrrp*

The apple harvest in high gear here now. Flat bed trucks all day long with crates full of apples headed for cold storage or distribution.