Test Equipment Anonymous (TEA) group therapy thread

[mansaxel]

Hmm, sure?



They're both connected to the same source.

Obviously the Fluke removed a redundant "9" from the display, because it was the "64" at the end that was the meat of the argument!

 

Bam! with attitude. Or something.

[Robert763]

Also, Fluke sez BAM, as usual:

Hmm, sure?



They're both connected to the same source.

Well
A/ The baby bumper is missing
B/ It's one of those modern software calibration things.

Seriously, it is in specification, 0.07%. However I have found that the older high end Flukes tend to be spot on +_ a count or so, but the modern automatically calibrated ones tend to be "just in". I wonder if this is an artifact of the automatic calibration software. Does it stop looking for a better correction as soon as it is in spec?
A side effict of this could be, by chance or design, the availabilty of the better specified 185 model. Is there  physical difference or do they just do a better calibration? This would allow sales of a "better" more expensive model with no acual difference apart from the model number. Ypu do get temperature and 4-20mA with the 185 but they are "only software"

[Vince]

I've already cleaned up the dial from a hp 200CD (from the same seller), not what I would call new and it took a few hours to sand & polish, still not quite happy with it, too shiny.
David

Yeah that's that problem whe polishing/sanding... you get rid of the pitting/defects, but you also lose the finish and the texture if present.


Well the positive thing at least onyur unit, is that the inside is in excellent nick, no rusty hardware not pitted aluminium. So even though the exterior loks pretty bad... it's only all you have to work on, so you an afford t spend all your efforts and time on it, because once that's done... well that will be it, cosmetic wise.

The dial you could try anodizing maybe ? Will have to investigate that route to restore my 575. The lower deck is pitted/corroded all over the place, only way to get rid of the corrosion is to sand it down, which of course destroys the finish. So I think I will try to see if one can do some DIY anodizing/plating to reconstruct /grow a  new layer of finish to make it look nice again.

[med6753]

Invasion of the mini's on bench 1. Here to provide encouragement and support to the 212 currently under surgery.

[Saskia]

good luck !

[Saskia]

just bid on some woodworking equipment ...

zat zere:
https://www.festool.de/produkte/holzbau/exzenterschleifer/575043---ets-ec1505-eq

Too many pinballs to resurrect, and the cabinets need to be properly restored.

*sigh*

[Vince]

I AM SCREWED !!!!!   I mean I am REALLY screwed !!!   


... trying to order brand new H/W nuts and screws to replace all the rusty ones in my Tek 575 curve tracer.

It's a nightmare.. have to learn all the English screw related stuff, my goodness 

Luckily the mechanical parts list gives the description of every screw and nut and washer so I Googled to understand how to decipher what all the numbers and acronyms meant. I think I kinda got it now... a pain, but I am getting there.

So it looks like :

1) First number : diameter... for sizes up to and including '10', it's a lot of fun : you have to multiply the number by  0,013" then add 0,060" to it !?      For sizes above '10', it's simpler, the diameter is expressed directly as a fraction of an inch.

2) Second number is number of TPI.

3) Third number is length, in fraction of an inch.

Then we have a 3 letter acronym like "BHS" or "PHP" (no BD nothing to do with computers !), which code the type of head you want.

- Middle 'H' is invariable and just means "HEAD".
- The first letter codes the shape/looks of the head, can be (F)lat, (P)an (cake), (R)ound, (T)russ, or (H)ex.
- Last letter codes the type of screw driver you need : (S)lotted for a flat screwdriver, or (P)hilips.

I found a picture showing what the various heads look like from the top and from the size, helps.
"Truss" sounds like a weird word... looks like a round head but large and very very flat....

So I would say the rusty ones in my 575 are mostly slotted pancake heads, and Philips Truss heads.

I also need some nuts with a built-in "External star lock washer "....though I guess I could compromise if need be, and just use a standalone lock washer + normal nut, as it would do just as well and once assembled you wouldn't be able to tell the difference anyway...

I also might need the odd countersunk head here or there.

I assume the length is expressed the same as in Frog land ? That is, for a flat head, the thickness of the head is NOT included, but for a countersunk head, it is included ?

Unfortunately the service manual does not have an exploded view of the 575, so I don't know the dimensions/type of the screw that I need. So will have to remove them first and measure diameter and length and TPI, how fun. 

For the diameter, should not be too difficult, as according to the parts list there are only a few different ones : 4 or 6 or 8 or 10. So I can just run the numbers to figure out how millimeters that equates to. Then I can just measure the diameter of my screws with calipers and see easily what imperial size that matches.

However to figure out the TPI, I would need a TPI gauge ! Anyone can recommend a decent cheap one on the web ?!

According to the parts list, 90% of the screws are 32 TPI, and a few are 40 and one is 26.


Then... the hard part : WHERE can I freaking buy all that stuff online ?! You can find screws on Ebay but trying to find the exact screw for each and every one that I need, might be fruitless yet waste hours of my time, plus I would have to pay shipping several times probably !

Would be cool if I could find a website of some screw manufacturer where I could buy direct from, and just tick of few boxes to configure exactly and quickly all the different screws that I need, and pay shipping only once.  Problem of course is mostly that finding such a vendor in FRANCE for IMPERIAL screws and nuts, is... a waste of time probably. And even if it existed, they would probably charge extra since it would be out of their main line of products...

So I would need I guess a place in the UK  !  So please all my TEA friends in the UK.... do you know of such a website/vendor ?!

Last problem: I don't know what kind of FINISH Tek used for their screw ! 60 years later they are all dull at best, but mostly al rusty, so it's hard to know for sure ! I have one Tek scope that looks about decent, and the screws on its outside, that hold the cabinet/chassis together, look like they have a light coloured finish, and kinda shiny. I would say it looks like a "normal"/standard finish, but I don't know the technical term to search for that corresponds to a "normal" screw ! 

[tautech]

I AM SCREWED !!!!!   I mean I am REALLY screwed !!!   


... trying to order brand new H/W nut and screws to replace all the rusty ones in my Tek 575 curve tracer.

It's a nightmare.. have to learn all the English screw related stuff, my goodness 

All US not English threads.
Look up sub 1/4" UNC and UNF sizes.

[Vince]

I AM SCREWED !!!!!   I mean I am REALLY screwed !!!   


... trying to order brand new H/W nut and screws to replace all the rusty ones in my Tek 575 curve tracer.

It's a nightmare.. have to learn all the English screw related stuff, my goodness 

All US not English threads.
Look up sub 1/4" UNC and UNF sizes.

Are you kidding me ?! The US do NOT use the same designation as the UK ?! So I can't even find the proper screws in the UK, have to pay to import them from some US vendor ?!  OH MY !!! 

[tautech]

I AM SCREWED !!!!!   I mean I am REALLY screwed !!!   


... trying to order brand new H/W nut and screws to replace all the rusty ones in my Tek 575 curve tracer.

It's a nightmare.. have to learn all the English screw related stuff, my goodness 

All US not English threads.
Look up sub 1/4" UNC and UNF sizes.

Are you kidding me ?! The US do NOT use the same designation as the UK ?! So I can't even find the proper screws in the UK, have to pay to import them from some US vendor ?!  OH MY !!! 

No kidding, these are standard sizes but these small ones are only available from specialist suppliers.
https://www.engineeringtoolbox.com/unified-screw-threads-unc-unf-d_1809.html

Edit to add
https://www.fastenerdata.co.uk/thread-chart

[tggzzz]

I AM SCREWED !!!!!   I mean I am REALLY screwed !!!   


... trying to order brand new H/W nut and screws to replace all the rusty ones in my Tek 575 curve tracer.

It's a nightmare.. have to learn all the English screw related stuff, my goodness 

All US not English threads.
Look up sub 1/4" UNC and UNF sizes.

Are you kidding me ?! The US do NOT use the same designation as the UK ?! So I can't even find the proper screws in the UK, have to pay to import them from some US vendor ?!  OH MY !!! 

You have no idea of how bad it was. BSW, BSF, UNC, UNF, and probably others.

But now we have left the EU, Boris has proudly announced a major benefit: we can use Imperial measures again     No mention of LSD, though. (To avoid confusion, that's pounds shillings and pence).

I suspect fleabay may be a useful source of a small number of bolts.

[xrunner]

Are you kidding me ?! The US do NOT use the same designation as the UK ?! So I can't even find the proper screws in the UK, have to pay to import them from some US vendor ?!  OH MY !!! 

Fly over here I'll take you to Home Depot it's just a few miles away ... 

[tautech]

Cmon Vince, even in aviation that you worked in for years there's a heap of different threads despite the decades of trying to standardize them.

Stuff I've had to work with:
BSW
BSF
UNC
UNF
ISO Coarse, Med, Fine
BSPT, Taper and Parallel
NTP, NTS
BA

And I'm very sure others can add more. 

[Cubdriver]

I AM SCREWED !!!!!   I mean I am REALLY screwed !!!   


... trying to order brand new H/W nuts and screws to replace all the rusty ones in my Tek 575 curve tracer.

It's a nightmare.. have to learn all the English screw related stuff, my goodness 

Luckily the mechanical parts list gives the description of every screw and nut and washer so I Googled to understand how to decipher what all the numbers and acronyms meant. I think I kinda got it now... a pain, but I am getting there.

So it looks like :

1) First number : diameter... for sizes up to and including '10', it's a lot of fun : you have to multiply the number by  0,013" then add 0,060" to it !?      For sizes above '10', it's simpler, the diameter is expressed directly as a fraction of an inch.

2) Second number is number of TPI.

3) Third number is length, in fraction of an inch.

Then we have a 3 letter acronym like "BHS" or "PHP" (no BD nothing to do with computers !), which code the type of head you want.

- Middle 'H' is invariable and just means "HEAD".
- The first letter codes the shape/looks of the head, can be (F)lat, (P)an (cake), (R)ound, (T)russ, or (H)ex.
- Last letter codes the type of screw driver you need : (S)lotted for a flat screwdriver, or (P)hilips.

I found a picture showing what the various heads look like from the top and from the size, helps.
"Truss" sounds like a weird word... looks like a round head but large and very very flat....

So I would say the rusty ones in my 575 are mostly slotted pancake heads, and Philips Truss heads.

I also need some nuts with a built-in "External star lock washer "....though I guess I could compromise if need be, and just use a standalone lock washer + normal nut, as it would do just as well and once assembled you wouldn't be able to tell the difference anyway...

I also might need the odd countersunk head here or there.

I assume the length is expressed the same as in Frog land ? That is, for a flat head, the thickness of the head is NOT included, but for a countersunk head, it is included ?

Unfortunately the service manual does not have an exploded view of the 575, so I don't know the dimensions/type of the screw that I need. So will have to remove them first and measure diameter and length and TPI, how fun. 

For the diameter, should not be too difficult, as according to the parts list there are only a few different ones : 4 or 6 or 8 or 10. So I can just run the numbers to figure out how millimeters that equates to. Then I can just measure the diameter of my screws with calipers and see easily what imperial size that matches.

However to figure out the TPI, I would need a TPI gauge ! Anyone can recommend a decent cheap one on the web ?!

According to the parts list, 90% of the screws are 32 TPI, and a few are 40 and one is 26.


Then... the hard part : WHERE can I freaking buy all that stuff online ?! You can find screws on Ebay but trying to find the exact screw for each and every one that I need, might be fruitless yet waste hours of my time, plus I would have to pay shipping several times probably !

Would be cool if I could find a website of some screw manufacturer where I could buy direct from, and just tick of few boxes to configure exactly and quickly all the different screws that I need, and pay shipping only once.  Problem of course is mostly that finding such a vendor in FRANCE for IMPERIAL screws and nuts, is... a waste of time probably. And even if it existed, they would probably charge extra since it would be out of their main line of products...

So I would need I guess a place in the UK  !  So please all my TEA friends in the UK.... do you know of such a website/vendor ?!

Last problem: I don't know what kind of FINISH Tek used for their screw ! 60 years later they are all dull at best, but mostly al rusty, so it's hard to know for sure ! I have one Tek scope that looks about decent, and the screws on its outside, that hold the cabinet/chassis together, look like they have a light coloured finish, and kinda shiny. I would say it looks like a "normal"/standard finish, but I don't know the technical term to search for that corresponds to a "normal" screw ! 

A quick glance at mine shows that most of the internal screws look to be 6-32 x various lengths with slotted pan heads, along with with some 8-32 slotted pan heads thrown in for variety.  I can look more closely later if you'd like.  That said, if I were replacing them, I'd use Phillips pan heads in place of the slotted - I despise slotted screws with a passion; it's such a PITA to keep a screwdriver in one of them.

The screws on the outside holding the longitudinal bar at the center (the part with the carry handles on it) look to be chrome plated Philips truss head screws; without removing one to check I'd say they look like 8-32 x 1/4" long.

For nuts with integrated lockwashers, search for Keps nuts.

I can look more closely later.  Shame you don't have something like a McMaster-Carr over there - maybe you do, by a different name?
https://www.mcmaster.com/screws/

-Pat

[Cubdriver]

Oh, and finish is probably zinc plated steel, though I'd be inclined to replace them with stainless, 18-8 or 316.  and that -26 number you quoted as a thread pitch is probably a -24, as in 10-24.  Can't think of a standard machine screw in the US with a 26 pitch.  Probably 98% of what you encounter will be one of the following: 2-56, 4-40, 6-32, 8-32, 10-32 and occasionally 10-24.  1/4-20 is also a standard as you start to get bigger.  There are #12 screws, but I can't recall ever encountering one in the wild.

-Pat

[Vince]

Cmon Vince, even in aviation that you worked in for years there's a heap of different threads despite the decades of trying to standardize them.

Yes 10 years in aviation but I was NOT a mechanic ! I was trained on the airframe ! Cutting holes in the A/C, hand crafting replacement parts to fix the damage etc... all the fasteners we use to put together the airframe, are all American and nothing else, so it's quite straightforward !   LGP, Hi-lock, Hi-lite, solid rivets, jo-bolts, what have you... all american stuff. Some of these fasteners are made in France for practicality, but still, they conform to the US sizes and designations ! 

[mansaxel]

I AM SCREWED !!!!!   I mean I am REALLY screwed !!!   


... trying to order brand new H/W nut and screws to replace all the rusty ones in my Tek 575 curve tracer.

It's a nightmare.. have to learn all the English screw related stuff, my goodness 

All US not English threads.
Look up sub 1/4" UNC and UNF sizes.

Are you kidding me ?! The US do NOT use the same designation as the UK ?! So I can't even find the proper screws in the UK, have to pay to import them from some US vendor ?!  OH MY !!! 

There are two major problems here:

• The UK did not, except for a short period between WW2 and Metrification, and then only half-heartedly, use the US-derived Unified threads. Instead they went on using the older Whitworth and BA systems that were invented in the 1800s.
• The UK is (or was, fucking idiotic Tories) pretty thoroughly metric these days, at least in terms of fasteners. There are exceptions, but they're rare. I did have serious problems locating a sensible outlet for BSW 1/2" and 5/8" screws for my lathe, for instance.

Do note that Whitworth threads are not the same thread form as Unified or Metric; 55° for Whitworth and 60° for Unified. Also, while most threads-per-inch numbers align for the larger diameters, at least for coarse threads, there are exceptions, like 1/2" where BSW is 12TPI and UNC is 13TPI.

Further, the dimensions used on an oscilloscope most likely would not be from the BSW or BSF ranges, but like most electric and electronic
 stuff would be BA (British Association), which is a completely separate system, of course quaintly defined with smaller numbers for bigger dimensions and bigger numbers for smaller dimensions (4BA is smaller than 0BA). It's also sortakinda metric, loosely based on a Swiss watchmaker thread system from the 1880s. Still in use for some electric stuff. I have an IKEA lamp with BA threads.

To conclude: The Teks are made in Oregon, where there is only now appearing metric hardware. You need to get your fasteners from the US, or maybe from a US vintage car spares part house.

As we concluded on Discord last Saturday, fasteners and the tools for them is a nice rabbit hole in and of itself; I have Douilles and Clés Mixtés in 4 systems, BSW, BA, UN/AF, and Metric.

PS: BSW labels tools in thread dimension, UNC/UNF in spanner size, like Metric. The BSW practice would be like calling a 13mm wrench a "M8 wrench".

[tautech]

Oh, and finish is probably zinc plated steel, though I'd be inclined to replace them with stainless, 18-8 or 316.  and that -26 number you quoted as a thread pitch is probably a -24, as in 10-24.  Can't think of a standard machine screw in the US with a 26 pitch.  Probably 98% of what you encounter will be one of the following: 2-56, 4-40, 6-32, 8-32, 10-32 and occasionally 10-24.  1/4-20 is also a standard as you start to get bigger.  There are #12 screws, but I can't recall ever encountering one in the wild.

-Pat

Yep has to be a misprint as all UN threads are 24 or 28 TPI.

[mansaxel]

Cmon Vince, even in aviation that you worked in for years there's a heap of different threads despite the decades of trying to standardize them.

Stuff I've had to work with:
BSW
BSF
UNC
UNF
ISO Coarse, Med, Fine
BSPT, Taper and Parallel
NTP, NTS
BA

And I'm very sure others can add more. 

The "Screened Banana plug" (PL259) and the N connector share the locking thread, 5/8" UN_E_F. You overlooked that, even if you probably worked with it.  Many CB antennas are 3/8" UNF; another example of thread often seen in electronics.

[mnementh]

So the TL/DR: Vince is screwed... and we're all NUTS!

mnem

[Vince]

Thanks everyone for the quick yet comprehensive and useful replies ! 

@Xrunner : yes would love to fly to the US to sort this H/W problem out, but not economical, I will never be able to afford to fly anywhere, too expensive for me !   

@Mansaxel : looks like almost studied this stuff enough to write a PhD thesis !    A rabbit hole it appears to be indeed, and one for a BIG rabbit !

@Cubdriver : thanks a lot for your practical help, you are my saviour, will contact you if needed ! 

Yes TPI on parts list is 26 not 24, so a typo on their part I guess ! 

Yep, most screw in the parts list are 32. Most are 6-32, some 8-32 and some 4-40. A few 10-32 too but Hex head,don't know where they are, so I probably don't need those...

As for replacing slotted wit Philips, not sure, it would hurt originality and look inconsistent... I can deal with those pan slotted heads OK, I never felt like I was losing my mind because of them. It's not like hter was a million of them and I was restoring these scopes by the dozne each week, so I can deal with a slight pain in the butt where required ! 

Thanks for the MacMaster web site, yes I was hoping for something like this ! I don't dream such thing would exist in France as why would it, and now you have all deterred me from buying screws from the UK for I would probably get screws that look good from a distance but don't fit well when I go to screw them in !

So I guess to avoid troubles, it's best to buy the screws from the US, and I am glad Cub is there ot assist with his 575 !   
hopefully together we can sort something out...

What I though I could possibly do to simplift the problem a bit, is to use Metric / locally sources screws in some places, as it IS possible here and there : where the screw is mated to a lone nut. A complete bolt. This way I can just replace both the screw and the nut, and therefore I can use Metric if I want !  Nobody will be able to tell the difference, not even me since I am already using my Metric wrenches to remove this nuts anyway ! IIRC I use size 8, 9 and 11mm in these scopes, it goes well. Keeps me from spending money on imperial wrenches !      I also use a Metric wrench to get the big retaining nut on the pots on the front panel. It's 5/8" but a 16mm deep socket fits just fine.

So I need to look at the 575 more closely, make a list of all the rusty H/W I need, see where I can use Metric, and see where I have no choice but order screws from the US... then buy a TON of them. This way even though I will pay an arm to import them, I would only have to fo it once. Then I would have enough screws to restore my very many Tek scopes.. screws will be there at hand ! 

Cub I wonder something : the little screws that hold all the tube sockets on the decks (I need to replace some of them). They don't have a nut, they screw straight into the aluminium sheet.. yet looking at the bit of thread that's exposed, they don't look like self tappers ?! They look more like machine screws to me, no ? Would Tek have gone through the trouble of tapping all these tiny holes ?!      Bottom-line : no sure what screw to order for these !!! 

[Vince]

So the TL/DR: Vince is screwed... and we're all NUTS!

mnem

In a NUTshell, yes ! 

[mnementh]

https://www.amazon.com/Stainless-Cutting-Imperial-Industrial-Measurement/dp/B095P17LJ6

https://www.amazon.com/Screw-Thread-Metric-Recommends-BCP675/dp/B07K7W3NQQ

The kit below would be the ones I'd recommend as you don't have to measure with calipers and guess the major dimension against a chart, except I'd want to see a set that goes down to a more civilized m2/m3 and at least 4-40; 2-56 would be better.

I mean, yeah... this set will likely gonna be fine for now, and the price is right... but you never know when you're going to get that bearing plate or shaft screw in 4-40 or some damned thing...

https://www.amazon.com/Bolt-Thread-Checker-Inch-Metric/dp/B08VBHCXKZ

mnem

[med6753]

You know what?

FUCK metric. 

[mnementh]

So the TL/DR: Vince is screwed... and we're all NUTS!

mnem

In a NUTshell, yes ! 

Pssssst... replace them all with stainless steel hex-drive button head screws. Bring it into the 20th century, now that we're in the 21st. 

mnem
*agitating-ily*