Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

Ah, you bought it then? I did think about bidding on it but decided against, fortunately. Glad it's gone to a fellow TEA-timer, looking forward to seeing a teardown.

[TERRA Operative]

Well, I found the 1MHz crystal is playing games in my SG503 Levelled sine-wave generator. This unit has been dropped in a previous life so I suspect damage. It won't oscillate after turning it on, but will randomly decide to start oscillating after an undetermined period of time and being poked at.
It's rated to +/- 0.005, so I went down to Akihabara and found a 1MHz crystal oscillator module that just needs 5VDC to run. I'll make a little adapter board to fit it in.
The frequency stability specs of the new one are +/- 50x10^-6 So should do well as an upgrade.

[AVGresponding]

Well, I found the 1MHz crystal is playing games in my SG503 Levelled sine-wave generator. This unit has been dropped in a previous life so I suspect damage. It won't oscillate after turning it on, but will randomly decide to start oscillating after an undetermined period of time and being poked at.
It's rated to +/- 0.005, so I went down to Akihabara and found a 1MHz crystal oscillator module that just needs 5VDC to run. I'll make a little adapter board to fit it in.
The frequency stability specs of the new one are +/- 50x10^-6 So should do well as an upgrade.

Is that first figure a percentage, because if it is, it's the same as 50ppm...

[Neper]

   
https://hartford.craigslist.org/wan/d/new-britain-fire-breathing-dragon-or/7435225636.html



   BWAHAHAHAHA!

They have one in Calais, France, and, yes, it can be hired. It's even even self-propelled:

https://www.lamachine.fr/spectacles/le-dragon-de-calais/

[TERRA Operative]

Well, I found the 1MHz crystal is playing games in my SG503 Levelled sine-wave generator. This unit has been dropped in a previous life so I suspect damage. It won't oscillate after turning it on, but will randomly decide to start oscillating after an undetermined period of time and being poked at.
It's rated to +/- 0.005, so I went down to Akihabara and found a 1MHz crystal oscillator module that just needs 5VDC to run. I'll make a little adapter board to fit it in.
The frequency stability specs of the new one are +/- 50x10^-6 So should do well as an upgrade.

Is that first figure a percentage, because if it is, it's the same as 50ppm...

Dunno , it's written exactly as in the parts listing in the Tek manual.
As long as the new part isn't worse, I'm happy.

I'm not a smart man when it comes to converting ppm and percent tolerance and stuff.....

[mansaxel]

I'm not a smart man when it comes to converting ppm and percent tolerance and stuff.....

Sounds like me and diminutive-prefixen on capacitance. Especially when the schematic contains just a figure and no scaling factor. We can deduce it's in Farad, from the -||- symbol, but not if it's pico/nano/micro -- milli is so uncommon that I'd think they'd go more "(sic!)" on it.  That's one of those shorthand traditions I'd rather not have.

Functional idiot, that's how I feel. Wonder if I'll get my next build to run; there were a bunch of "educated guesses" that might very well be three orders of magnitude or more wrong. I've got a pair of assortments (only film and ceramic, electrolytes I buy only in respectable outlets) on the way from China, so I guess there's  a chance at having the right value when I've fucked up. 

Also concluded that I forgot to order potentiometers for same build. Those are available cheaply in-country, so we'll make do anyway.

[tggzzz]

PP Auction catalog is out. 
...
PP are  too darn far.

Lots 550 and above are in Blackburn, which I believe is nearer you. I wonder how many people that will catch out!

[Cerebus]

Well, I found the 1MHz crystal is playing games in my SG503 Levelled sine-wave generator. This unit has been dropped in a previous life so I suspect damage. It won't oscillate after turning it on, but will randomly decide to start oscillating after an undetermined period of time and being poked at.
It's rated to +/- 0.005, so I went down to Akihabara and found a 1MHz crystal oscillator module that just needs 5VDC to run. I'll make a little adapter board to fit it in.
The frequency stability specs of the new one are +/- 50x10^-6 So should do well as an upgrade.

Is that first figure a percentage, because if it is, it's the same as 50ppm...

Dunno , it's written exactly as in the parts listing in the Tek manual.
As long as the new part isn't worse, I'm happy.

I'm not a smart man when it comes to converting ppm and percent tolerance and stuff.....

Ever since I memorised the fact that 0.0001% is 1ppm I can do the conversion just by visually isolating the appropriate digits in a percentage, or visually imagining the percentage decimal point into place in a figure that's in ppm.

e.g.

0.003% => 0.0030% => 30ppm
300ppm => 0300 ppm => 0.03%
     

[Vince]

I avoid that kind of method because it reallies on the fact that on several arbitrary tgins which you might lose track of after too much time not using it...  like 0.0001% is 1ppm ... oh I am not sure now, might be 0.001 or 0.00001%...

So I prefer to just simply calculate it...

% = 10-2
ppm = 10-6

So just move the decimal point 4 positions one way or the other, to convert one to the other...

0.005% time 10,000 is 50ppm, take a split second and can't go wrong...

To speed it up one might remember it's 4 decimal places... but if in doubt, takes a split second to figure out a million divided by one hundred is 10,000....

[Cerebus]

Sounds like me and diminutive-prefixen on capacitance. Especially when the schematic contains just a figure and no scaling factor. We can deduce it's in Farad, from the -||- symbol, but not if it's pico/nano/micro -- milli is so uncommon that I'd think they'd go more "(sic!)" on it.  That's one of those shorthand traditions I'd rather not have.

If someone has obviously used strict SI prefixes throughout something then mF isn't a problem but there are so many unit challenged people out there that when seeing mF in isolation it's anyone's guess what was actually intended without at least partial reverse engineering of the circuit it's in. Then there are those who will never get why it is important to be precise and won't understand what I mean when I write 1.7 kK.


It's the melting point of mild steel.

[mansaxel]

Sounds like me and diminutive-prefixen on capacitance. Especially when the schematic contains just a figure and no scaling factor. We can deduce it's in Farad, from the -||- symbol, but not if it's pico/nano/micro -- milli is so uncommon that I'd think they'd go more "(sic!)" on it.  That's one of those shorthand traditions I'd rather not have.

If someone has obviously used strict SI prefixes throughout something then mF isn't a problem but there are so many unit challenged people out there that when seeing mF in isolation it's anyone's guess what was actually intended without at least partial reverse engineering of the circuit it's in. Then there are those who will never get why it is important to be precise and won't understand what I mean when I write 1.7 kK.


It's the melting point of mild steel.

I was going to go on a rant about milli-milli-Farad and "MF", but decided against it. Thanks for helping out!

[Andrew_Debbie]

Lots 550 and above are in Blackburn, which I believe is nearer you. I wonder how many people that will catch out!

I spotted that and looked at the location on Google maps.   I don't recall anything in Blackburn I wanted.

[factory]

PP Auction catalog is out. 

TDLR;  I doubt I will be bidding.

Large amounts of junk unless you collect PAL vector scopes.

A few interesting lots of interest (to me)

7  - Wavetek 164.  Looks like the same one as last time?

Yes that was lot 66 in the last sale won by stream-light (along with far too many lots), I can just about see the previous number in the current pictures.

Lots 550 and above are in Blackburn, which I believe is nearer you. I wonder how many people that will catch out!

Nothing that interests me in the TTI Blackburn lots either, for some unknown reason I can't see any pictures on those lots above 559 (ignoring the blank lots).

David

[mansaxel]

Lots 550 and above are in Blackburn, which I believe is nearer you. I wonder how many people that will catch out!

I spotted that and looked at the location on Google maps.   I don't recall anything in Blackburn I wanted.

Not even 4000 holes that fill the Albert Hall? 

(oh, boy)

[Saskia]

cleaning out the old appartment. Need to properly clean the kitchen, stove, floor, etc.

And then I found sumting called Kärcher.

A steam cleaner does help.

a lot.

mah back hurtz

[THDplusN_bad]

My "Isolavi 7" isolation tester from Hartmann und Braun gives me grief. Only 10 years after I have repaired it for the 1st time - I shall file a complaint letter... 
This thing is from 1972. Its simple schematics are attached. My version does not even match with the schematics.
The darn simple thing won't oscillate... My version does not even match with the schematics. It looks like both Ge-transistors type AD148 and the transformer are toast. The transistors could be replaced easily with a pair of Si-PNPs, but not the transformer.
I had replaced the diodes on the secondary side with "modern" UF4007s and replaced the rechargeable battery and its clumsy charger with 5x AA-sized Eneloops. It has worked nicely since then.
Life is not good...

Cheers,

THDplusN_verybad

[Robert763]

Skanky Tek of the week
/www.ebay.co.uk/itm/134011078013

"used" but "untested no returns"
I'm tempted to buy it and raise a "not as described case" but I don't think I want to have it near the house.

[factory]

The hp 5216A is nearly on the "it's dead Jim pile", turns out to have manufacturing defect, one of the wires going to the transformer primary was trapped underneath the transformer, eventually it had damaged the insulation & shorted out half of the transformer primary, i.e ended up with 230V across one of the 115V windings, resulting in the blown fuse & it getting sold for spares on evilbay.

Ha! We can conclude that there worked someone at hp who didn't care for the well-being of striped green transformer leads.  I had a very similar error on my 428b; only that in my case, it was either a GFCI breaker shot, or a fuse blow, depending on which way the mains plug was inserted (We have CEE 7/4 plugs, so the alternating current is free to alternate). I managed to test both cases.



It was on one of the outer ends of the two 120V windings, so shorting it to ground just blew protection, not the meter.  I fixed it with clear shrink toobing.

Not so lucky for me, the short was at the join between the two 115V windings. Knowing my luck the rest will be knackered too. 

Thinking about it, it was bought from the EU, your crappy reversible plugs may have blown the winding in one direction & the fuse in the other.

David

[tggzzz]

Lots 550 and above are in Blackburn, which I believe is nearer you. I wonder how many people that will catch out!

Nothing that interests me in the TTI Blackburn lots either, for some unknown reason I can't see any pictures on those lots above 559 (ignoring the blank lots).

The pictures trickle in slowly. Yesterday they were only up to lot 400.

I hate it when a company tells me about an "important <whatever>" - and when I go there there's nothing to see. FFS, why don't they wait until it is up before they inform their (potential) customers.

[Andrew_Debbie]

Not even 4000 holes that fill the Albert Hall? 

(oh, boy)

It is ~130  miles from home.   I doubt I can get a week day off in February.    After months on Furlough and then WFH,  I'm very busy working on-site.   


Unless the MRI scanner stays broken.  Even then I have to be around most of the time.

Today's weekly Echo Planar Image EPI) stability test results:

That black spot in the SFNR image is verywrong.  There is a huge noise spike at the centre of the field of view.   We tried all the obvious things like rebooting, cleaning, and looking for FOD.   Also checked that we still had a Faraday cage.  Engineer coming tomorrow. 

[m k]

I'm wondering what this Akro-Mils 24-pack means.

https://www.amazon.com/Akro-Mils-30110-12-Inch-2-75-Inch-Plastic/dp/B003EV7C58

About this item

    STORAGE BIN DIMENSIONS- Outside (11-5/8-Inch x 2-3/4-Inch x 4-Inch), Inside (10-1/4-Inch x 1-5/8-Inch x 4-Inch) – Case of 24

Or were you wondering about the name...? I'd guess the bins are made to fit in the Akro-Mils industrial storage system of cabinets like this one:   

   https://www.digikey.com/en/products/detail/industrialsupplies.com-llc/B646591/14089805

mnem

(I thought I've already answered)

Mainly pricing, then sizing and materials.

Cabinet is a bit pricey for light stuff if boxes are couple hundreds.

Since boxes are not stackable wall thickness is probably much less than stackable ones but it shouldn't be a problem with electronics and one row per self.

[AVGresponding]

I don't recall anything in Blackburn I wanted.

Except the road out, presumably...

[Cerebus]

Lots 550 and above are in Blackburn, which I believe is nearer you. I wonder how many people that will catch out!

I spotted that and looked at the location on Google maps.   I don't recall anything in Blackburn I wanted.

Apparently they have lots of holes. Possibly useful if you want to make your own semiconductors and already have a copious supply of electrons. 

Edit: Måns had beaten me to it, but mine had actual electronics content.

[nixiefreqq]

HEY AVG

an envelope landed in the mailbox this afternoon with elizabeth regina on the outside and a dead president on the inside.

THANKS! 

ummmmm.  you sent more than you were supposed to......but that's ok.  will get even by using the excess to acquire carrot cake.

[Cerebus]

cleaning out the old appartment. Need to properly clean the kitchen, stove, floor, etc.

And then I found sumting called Kärcher.

A steam cleaner does help.

a lot.

mah back hurtz

Until you clarified I thought that you meant that you'd pressure washed the whole apartment. I've lived places that could have done with that...