Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

Given I'm drinking it as a component of Moscow Mules, the alcohol content is somewhat moot...

[bd139]

Ahh vodka. Pleasant memories . I had a party trick years ago which I couldn't do now. Take a 2L bottle of coke, pour half on the ground, fill the empty half with vodka and drink it on the train in the way into London for a night out.  .  One night I kicked a train going past at about 60 mph.  .  Barely drink anything now - probably for the best

[duckduck]

cleaning it is not the big deal.
I am just aggravated because this damage could have easily been avoided by packing it correctly.
I could possibly send it back, but I would have no power supply if I did so

You might end up with it free if you complain. I got a free PL330QMD because they packed it loose and it rattled around. Plug exploded and the master power switch was destroyed but this was a £3 fix. Complaining works at least 50% of the time. A similarly buggered HP 6216A power supply I received to yours was however (ebay user jvincent120) a pain in the arse to deal with the seller.

Years ago I won a working old analog scope on ebay for next to nothing. I was so excited until I opened the box and it looked like the bits you see on the pavement by a car accident. The seller had just put the poor thing straight into a big cardboard box with no padding and it was destroyed in shipping. I sent pictures and the seller refunded everything. I ended up binning it.

Great story, eh?

[bd139]

Ouch. Had a couple myself like that. Plus stuff tends to look end up looking like that if it doesn't go well during the repair 

[tggzzz]

In all honesty... that signal on med's 2465 is a gorgeous example. Brings a tear to my eye; knowing this generation will never know the joy of actually SEEING the signal, even through a "microscope lens", as opposed to seeing a transcript of what a computer subroutine THINKS it sees and extrapolates from datapoints.

mnem
 

Turn off interpolation, and look at the unconnected dots. Then you can see what you can't see.

[duckduck]

And now for Something Completely... ON TOPIC:



Looks like we have a new contender for "Worst cheap POS Oscilloscope available via the slow boat from China": MUSTOOL-MDS2112P on bang-em-good

  izzat... "10KHz memory depth"...? Can that actually be 10 Kilobits...? Furr Realllzzz?!? 

I think I'd rather have that CRO I posted about the other day...    

mnem
"I'm never surprised, but I am constantly amazed at the SHIT some people will try to sell."

Plot twist: the screen image in the picture above is not simulated.

[tggzzz]

The slow rise time may also be the dodgy BNC cable I used. Maybe I should try some other connection?

McBryce.

I prefer to connect the step gen directly to the scope input with only a bnc-bnc adaptor. The scope input should be 50ohms, preferably without 15pF in parallel.

At high edge rates some cable lengths and some clock rates, that 20pF will have unfortunate consequences, even with a 2465.

[tggzzz]

Ouch. Had a couple myself like that. Plus stuff tends to look end up looking like that if it doesn't go well during the repair 

Under this circumstances, decent stuff gets dismantled and stored for when I want random bits of metal. My 5371 ended up like that, minus its working and salvaged OCXO.

[duckduck]

Mustool = μStool

[AVGresponding]

cleaning it is not the big deal.
I am just aggravated because this damage could have easily been avoided by packing it correctly.
I could possibly send it back, but I would have no power supply if I did so

You might end up with it free if you complain. I got a free PL330QMD because they packed it loose and it rattled around. Plug exploded and the master power switch was destroyed but this was a £3 fix. Complaining works at least 50% of the time. A similarly buggered HP 6216A power supply I received to yours was however (ebay user jvincent120) a pain in the arse to deal with the seller.

Years ago I won a working old analog scope on ebay for next to nothing. I was so excited until I opened the box and it looked like the bits you see on the pavement by a car accident. The seller had just put the poor thing straight into a big cardboard box with no padding and it was destroyed in shipping. I sent pictures and the seller refunded everything. I ended up binning it.

Great story, eh?

Aieeee... commiserations... I think we've all been there, or thereabouts.

I still have a PM3218 in the repair queue that has a jigsaw puzzle for a display bezel, and a control panel whose concavity is definitely not in the original design...   

[ch_scr]

I bought a Allied Vision "Manta" C-Mount GigE Camera on ebay months back, did not work. Support was helpfull enough to suggest additional tests, told me "propably ethernet phy is damaged", please send in for repair. Today i got the new phy IC, got it soldered in, camera works a treat after initial struggles Big thumbs up for the support being fast, competent and very helpfull - even though I'm a private individual that bought a second hand EOL device! These companys deserve a mention, as this kind of support has gotten rare.

[Kosmic]

I'm with McBryce on this one... there might be something wrong there. Whether it's the source or something in the frontend; I just remember mine being a lot squarer with 10MHz SQ, even with cheap probes. I'd do a comparison against the other channels, m'self. 

mnem
 

Absolutely not. It's working properly and you'll have to take my word on it. But if forced I'll whip out the 7904 and prove it.

Ok, you went and made me do it, I've gone and set up my 2465 just for you. Here's a 10MHz square wave produced by a Siglent SDG2042X into my 2465, which incidentally has never been recapped and still has all the original Rifa madness in there as God intended it to be! Cracks or not!

McBryce.

Well gee....that's pretty lousy compared to my 10MHz square wave. I think YOU need a better signal source. 

The SDG2042X is rated 9ns rise time. If the heathkit scope calibrator is really 1ns it will definitely look squarer.

[tautech]

The SDG2042X is rated 9ns rise time. If the heathkit scope calibrator is really 1ns it will definitely look squarer.

Indeed.

You can squeeze another ns faster in Pulse mode but that's it for standard waveform set while the newer and more lowly SDG1000X do rise times as fast as 3.8ns which is not too bad for a $319 AWG. 

[Neomys Sapiens]

I'm with McBryce on this one... there might be something wrong there. Whether it's the source or something in the frontend; I just remember mine being a lot squarer with 10MHz SQ, even with cheap probes. I'd do a comparison against the other channels, m'self. 

mnem
 

Absolutely not. It's working properly and you'll have to take my word on it. But if forced I'll whip out the 7904 and prove it.

Ok, you went and made me do it, I've gone and set up my 2465 just for you. Here's a 10MHz square wave produced by a Siglent SDG2042X into my 2465, which incidentally has never been recapped and still has all the original Rifa madness in there as God intended it to be! Cracks or not!

McBryce.

Fuh. That Siglent isn't even able to produce a proper ringing!

[BreakingOhmsLaw]

Hello, my name is BreakingOhmsLaw and i suffer from GAS.
Today if have something for you, that probably is new even to this forum.

I present to you *drumroll* the Citizen CQT-101-C Quartz tester.
What is it? Well, basically its a frequency counter for wrist watches. It comes with a little pedestal for you to place a wrist watch on. Theres a hypersensitive microphone inside that listens for the watch ticking.
The ticks are measured with high precision, and the device shows the deviation of the watch in seconds per day.
There no CPU inside. It's just logic gates and counters, making clever use of an 4.320 MHz OCXO. In case you are wondering why:
24h x 60m x 60s x 50 = 4.320.000
I will be doing  teardown and restore thread that i'll link in later.

Edit:
https://www.eevblog.com/forum/testgear/teardown-and-restauration-of-a-citizen-cqt-101-c-quartz-tester/

[ Specified attachment is not available ]

[Cubdriver]

Interesting bit of kit, B.O.L.

-Pat

[mnementh]

Got a little surprise on the way for y'all; something VERY special, and very TEA-related. The above video is a hint; though I've scattered a few hints through the thread since I made this special acquisition, which is due for delivery any minute now.

Just let your eyes follow the wibbly light and rela-a-a-ax...   

mnem
*namaste* Peace be with you, my friends.

[Specmaster]

Who the hell calibrates a scope? That's like putting lipstick on a pig; it might make it superficially more attractive, but it's still just bacon walking.   

Oh, and SOMEONE here introduced me to Crabbies Alcoholic Ginger Beer. I don't know who you are, but I will find you, and I will breathe ketones on you!   


EDIT: Watching this on yt, heartliy recommend it. What a legend, what a loss   

Well I introduced you to The Ginger Grizzly, not Crabbies Ginger Beer, don't tell me that you went and brought some Crabbies then  , They are like chalk and cheese 

[mnementh]

      

   You can't even tell that there's ringing with either sample. What all you've done here is to prove that a 40-year-old scope still has value. 

mnem
 

That Siglent only has a 50MHz B/W. I would cut it SOME slack.

I wouldn't 

Why not? Just cuz it's med...? 

In all honesty... that signal on med's 2465 is a gorgeous example. Brings a tear to my eye; knowing this generation will never know the joy of actually SEEING the signal, even through a "microscope lens", as opposed to seeing a transcript of what a computer subroutine THINKS it sees and extrapolates from datapoints.

mnem
 

Turn off interpolation, and look at the unconnected dots. Then you can see what you can't see.

Being able to figure out what you can't see is not the same as being able to see it. Those dots are the same kind of lie as the statistics on any kind of chart used by any politician to sell whatever big lie they're pushing at the moment.

mnem
Any DSO is just a box with multiple instance of Plato's Cave playing inside it.

[tautech]

Those dots are the same kind of lie as .............

Nope, they're what interpolation waveform reconstruction is based on, however any scope with a small memory depth will have lesser dots for interpolation to work with.
Yet it's always the operators understanding that allows settings to be made so to minimise interpolation errors.

Repetitive waveforms aren't usually a problem but fast edges and non-repetitive waveforms are.

-----------------------------------------------------
tautech
totally dotty !

[med6753]

You guys are relentless.  Here, go chew on and argue about this while I go get some sleep. 

19.999644MHz on a 7904 with a 7A24 plug-in. 

[mnementh]

Those dots are the same kind of lie as .............

Nope, they're what interpolation waveform reconstruction is based on, however any scope with a small memory depth will have lesser dots for interpolation to work with.
Yet it's always the operators understanding that allows settings to be made so to minimise interpolation errors.

Repetitive waveforms aren't usually a problem but fast edges and non-repetitive waveforms are.

-----------------------------------------------------
tautech
totally dotty !

A collection of datapoints is just that; it is NOT reality, but rather an approximation thereof.  You don’t know what you’re NOT seeing in the spaces between those datapoints; all you have is the computer’s best guess. As med’s example makes abundantly obvious, in some cases that guess is pure shite.

Some DSOs guess better than others, but at the end of the day, even the raw datapoints are only a guess at what’s really going on. Just like with the politician’s chart, a poorly crafted program can make those datapoints say anything.

mnem
*toddles off to ded*

[bitseeker]

Hey all. So I decided to end my poorly thought out shelf imposed exile. Mea culpa. Besides, I miss all of your ugly mugs. 

Welcome back! We like your face, too.

[bitseeker]

You know you paid too much when ... no one else is interested to bid the starting price.

So maybe I have been ripped off, but you can't complain about the delivery: 46 hours from auction's end to its arrival at my front door.

I'm not all that sure I really bought an AC calibrator:

Nice . Added to POI.

[bitseeker]

   Lockdown Friday in the Shack. There was no Salads Killed in the process. Burp 

Welcome to bean's Heart-Attack Shack...   (says the guy who just made fried hamsteaks and oven-fried tater cubes with pumpernickel toast on the side for dinner)

Ah, but bean's got 200kg of caffeine-laden ballast to brew up an artery-blasting potion for after dinner.