Test Equipment Anonymous (TEA) group therapy thread

[Martin.M]

i am working in the 8300A Nixie Fluke.
The both lower R ranges, I cannot adjust them to be exactly, the trimm pot is full clockwise an i am missing 2mm..

[Cerebus]

That's the pub we need. Instead we got Samuel Smith chain, the owner of which who has managed to ban phones, ipads, laptops, swearing, sports, paying by card, live entertainment, bikers, jukeboxes, slot machines. So instead you can sit around and be fucking miserable cirrhosis victim of yesteryear. 

Hmm...

Banning:

phones
ipads
laptops
	I go to the pub to escape that sort of thing.
swearing
sports
paying by card	Neutral
live entertainment*	(less the live entertainment is every bloody night - sometimes a man just wants a quiet drink, in which case )
bikers
jukeboxes	(unless persistently too loud, in which case )
slot machines.	(Commercial gambling is the only vice I heartily disapprove of as it is inherently exploitative.)

How does he feel about soldering on his Britannia tables?

^* There's a pub I used to go to occasionally up the Caledonian Road that had a band every night but also had a decent sized back room off the main room that had decently soundproof glass doors, so you could have a quiet drink if you weren't in the mood for the band and still see who was coming and going. They also used to come round during drinking up time and offer to call a cab for you. Decent boozer, can't remember the name, and it's probably changed hands by now anyway.

[Martin.M]

It uses two EF12 / EF12K.

they are also good to be stocked for retirement time,
every year you pay 10,- more each. I have a little box with AC701k, to my 80th birthday I will put them in the ebay.

Martin

[BU508A]

There is some neat music history in this little side discussion... 

It seems to me that with modern components (pancake transformers, better electrolytic caps, better rectifiers etc) and a little sheetmetal work for magnetic shielding, you should easily be able to make a fully isolated low-EMI power supply module right inside that cavernous box; preserving at least the appearance of the original design. Just a thought. 

Yes, I've considered that. Toroid transformer, magnetic shield etc. But the best magnetic shield is distance. And that is why I am going for an external PSU, so the danger of catching unwanted magnetic stray fields is much lower that with any fancy PSU in the same case. I think for the same reason has Neumann used an external PSU for the U47 .

[mnementh]

Yeah, no... I totally agree that separate PSU is the BEST, surest way to solve the problem. I was just thinking as a hobbyist tinkery experiment, to see if you COULD do it without killing yourself. I totes think it is possible, and might be a nice modern-day update to that ages-old mod you mentioned.

Carry on!

mnem
 

[mnementh]

Jeezus H. Christ a-hoppin' on a pogo stick... people up here in the big frosty are just fucking cray-cray when it comes to computer parts. Trying to get real money for 3-generations-old 120GB SATA SSDs ($40 + shipping!!!)  and used is even worse... crusty-looking no-name 4GB DDR3 modules (I mean SERIOUSLY... couldn't even be arsed to brush the dust off for the pictures...?) for $25 when I can buy new Corsair for $22 from Amazon.ca with Prime next-day. 

Fuckwits.

K... just needed to get that off my chest. 

mnem
That's one BOUNCY Jesus.

[Dek]

Ahhhhhh...therapy.

Got this 'Gould' DMM along with the Keithley 177.
Not sure what it was when I bid, but it is in fact a re-badged Keithley 191 with a nice bonus inside..... the AC option.
Bad news it the display flickers like a 80s disco and then turns off.
I've checked the rails, +-15v are OK, problem with one of the 5v rails though, this starts Ok then drops to about 2v.
Got a set of caps on order and try recapping first, then may have to look a bit deeper.

The Gould front panel label has seen better days. It might stick back down with a bit of careful persuasion.

[beanflying]

There is some neat music history in this little side discussion... 

It seems to me that with modern components (pancake transformers, better electrolytic caps, better rectifiers etc) and a little sheetmetal work for magnetic shielding, you should easily be able to make a fully isolated low-EMI power supply module right inside that cavernous box; preserving at least the appearance of the original design. Just a thought. 

Yes, I've considered that. Toroid transformer, magnetic shield etc. But the best magnetic shield is distance. And that is why I am going for an external PSU, so the danger of catching unwanted magnetic stray fields is much lower that with any fancy PSU in the same case. I think for the same reason has Neumann used an external PSU for the U47 .

In doing a little looking at 48V for Microphones and ran across this https://sound-au.com/project96.htm

Also interestingly the internals of the cheapy BM800 mic I am getting and some mods to reduce the noise floor

[bd139]

How does he feel about soldering on his Britannia tables?

He'd probably shut the pub instantly 

^* There's a pub I used to go to occasionally up the Caledonian Road that had a band every night but also had a decent sized back room off the main room that had decently soundproof glass doors, so you could have a quiet drink if you weren't in the mood for the band and still see who was coming and going. They also used to come round during drinking up time and offer to call a cab for you. Decent boozer, can't remember the name, and it's probably changed hands by now anyway.

Strange to hear Caledonian Road mentioned randomly here. Spent the first years of my life living and going to school around there in a particularly nasty estate and got dragged in most of the pubs in the area which were quite nasty at the time. If it was after about 1984, it probably vastly improved. Certainly couldn't get any worse.

Think my favourite pub was the Salisbury Arms in Cambridge. Usual London haunt was the Devonshire Arms in Camden. Good selection of beers, music and floozies

Anyway I'm starting to sound like a Viz character now: http://viz.co.uk/wp-content/uploads/2015/02/050_viz207_twats.jpg

[Cerebus]

If it was after about 1984, it probably vastly improved. Certainly couldn't get any worse.

Mid to late '90s, when I was still young enough to go out boozing late on a working day night  and still make it to the office in a fit enough state to work the next day.

[Specmaster]

@med. The reason why I'm not falling into that particular rabbit hole is because who is to say that reference A, B or C and so on is correct. As you can see from your own reference modules, they do vary a few mV but in the grand scheme of things they pretty much agree with each other and so do your meters. I have also got myself 2 sources of references and 1 of those also does current. When it comes to voltages 1 is like yours 2.5, 5, 7.5 and 10V, the other has 2 ranges 1 to 100mV and the other 1mV to 10V and on current from 0.001mA  to 24mA and I'm able to increment them in 1mV or 1mA steps.

Now if I calibrate the volts against 1 reference device and then check using the other they do not agree precisely, they are a few mV out and to my mind that is A/ to be expected because engineering tolerances, and B/ they came from 2 different factories and so, were set up against 2 different reference standards.  Now that to my mind, explains the differences between your Fluke 8800A's and the Siglent.

That is why I've said that in most cases you will see on service charts, voltages generally to 1dp only and also as mentioned before, the odd 10mV or so is not a deal breaker on the type of work we do anyway. Where I see the extra resolution being a distinct advantage is not being completely accurate down to the 4th, 5thdp whatever, but in trend spotting, i.e. is a battery charging or discharging where those extra digits will enable a trend to be spotted that much earlier.

One has to be, in my mind, sensible about all of this volt nuttery business because if you gave me one of your meters to check against my voltage reference, I would obtain a complete different set of figures to you. The only way of getting every meter to agree would be to set them up using the same reference device, and even then there would be still be some differences as the specs for each meter reads +/-.00x% + x digits, so there you already have meters coming of the same production line that could be slightly different on the least significant digits. I have just done a quick test on my collection of bench meters, and they all agree from cold within 1mV and if I wanted to measure uV then I'd be sourcing a dedicated meter for that.

You have to take a pragmatic view otherwise you could be spending fortunes on gear and still not get all meters agreeing and rolling over of digits in harmony and for what? What actual benefit does it give you that you can translate into a real positive end result on your work? I bet even that poor old Fluke that you decided to make a spares donor was right up to 3dp with maybe 1 or 2 digits out 

[tautech]

@med. ................
You have to take a pragmatic view otherwise you could be spending fortunes on gear and still not get all meters agreeing and rolling over of digits in harmony and for what? What actual benefit does it give you that you can translate into a real positive end result on your work?

That's exactly the position I got to owning a 6.5 digit SDM3065X so I sold it rather than fall into that rabbit hole.....mainly as the little repair work I do now doesn't require such accuracy. So just a Fluke 15B and a good set of smart tweezers does all I need now. 

[xrunner]

Category: Simple but useful

3D printed pointer for pics -

[Specmaster]

@med. ................
You have to take a pragmatic view otherwise you could be spending fortunes on gear and still not get all meters agreeing and rolling over of digits in harmony and for what? What actual benefit does it give you that you can translate into a real positive end result on your work?

That's exactly the position I got to owning a 6.5 digit SDM3065X so I sold it rather than fall into that rabbit hole.....mainly as the little repair work I do now doesn't require such accuracy. So just a Fluke 15B and a good set of smart tweezers does all I need now. 

Exactly, I have bench meter wise, 1 x 4.5, 4 x 5.5 and 3 x 6.5digits and I can use anyone I like and feel confident with it, I just got the added digits because I grab them at a reasonable cost and it also goes with the territory of being a TEA. If I had the space available I'd probably be rivalling med with his scopes 

[Specmaster]

Category: Simple but useful

3D printed pointer for pics -

(Attachment Link)

I like that, simple but very useful, saves editing the photo before uploading.

[PA0PBZ]

Category: Simple but useful

3D printed pointer for pics -

(Attachment Link)

I like that, simple but very useful, saves editing the photo before uploading.

Now print the alphabet to make the annotations  I prefer Paint 

[Cubdriver]

xrunner, that's a friggin' GREAT idea!!   

-Pat

[tautech]

Category: Simple but useful

3D printed pointer for pics -

(Attachment Link)

3dp files ?

@ bean, care to print me just a few of these ? In nipple pink please...my fav color.
........exits stage left.............

[xrunner]

3dp files ?

Sure, attached. Multiply and size as needed in slicer.

[AVGresponding]

Here's a yt vid that might interest mnem, and any other model aircraft types.

I'm more into rc cars myself (electric ofc, none of that nitro rubbish), but I can appreciate a well enginerded model of about any vehicle.

[bd139]

3dp files ?

Sure, attached. Multiply and size as needed in slicer.

Ooh going to print that tomorrow 

[grizewald]

Specmaster is right on the mark with his comments.



There's a maximum disagreement of 11 microvolts from the nominal 0.01V that the Time reference is set to. It bugs me much more than it should. What bugs me even more is how the disagreement changes as I change the reference output to step through the various ranges on the meters. I'm almost resigned to never knowing who is right and who is wrong.

The only way out is to fly to Taiwan and steal TiN's new toy!

(With apologies for the extended absence. I see mnem has turned into a Canadian while I was away.  )

[Specmaster]

Specmaster is right on the mark with his comments.



There's a maximum disagreement of 11 microvolts from the nominal 0.01V that the Time reference is set to. It bugs me much more than it should. What bugs me even more is how the disagreement changes as I change the reference output to step through the various ranges on the meters. I'm almost resigned to never knowing who is right and who is wrong.

The only way out is to fly to Taiwan and steal TiN's new toy!

(With apologies for the extended absence. I see mnem has turned into a Canadian while I was away.  )

Thank you, now if all of our meters were analogue, we would each and every one of us argue that they were all bob on, am I right? Even with Tins new toy, they would all be differant.

[bd139]

This is why I mostly use the fluke 87 

[Dek]

Specmaster is right on the mark with his comments.

There's a maximum disagreement of 11 microvolts from the nominal 0.01V that the Time reference is set to. It bugs me much more than it should. What bugs me even more is how the disagreement changes as I change the reference output to step through the various ranges on the meters. I'm almost resigned to never knowing who is right and who is wrong.
<snip>

Hi Grize,

What's the meter on top of the Voltage standard? Looks like it's the boss

Dek.