Test Equipment Anonymous (TEA) group therapy thread

[Neper]

And a quick video showing that more of the lamps in the display are now working:

Brilliant. Absolutely brilliant. Thanks for showing.

Ralf

[nixiefreqq]

And a quick video showing that more of the lamps in the display are now working:



(I need to get a camera that can close focus!!)

-Pat

WOW!

[Specmaster]

Midnight, somewhere.

Beautiful scene, but I hate summer with all my heart¹.


¹Except for the ten minutes between 23:50h and 24:00h on 31st of August.

Ok, I'll be the one that bites on this, why are those 10 minutes OK then?

[Vince]

Bah, I just won a TDS220, with some parallel port only version of a comms module.
Paid equal to US$62, with some probe and a Japanese manual.

Lets see if it actually works when it arrives. 

That's 4 or 5 times cheaper than here....I now understand why you moved to Japan... not because of the wife, but because of the dirt cheap TE, THEN only did you start looking for a wife locally, not the other way around ! 

[BU508A]

Midnight, somewhere.

Beautiful scene, but I hate summer with all my heart¹.


¹Except for the ten minutes between 23:50h and 24:00h on 31st of August.

Ok, I'll be the one that bites on this, why are those 10 minutes OK then?

Because they are the last 10 minutes of summer.
Explanation: https://www.itv.com/news/wales/2021-08-31/what-is-meteorological-summer-and-why-does-it-end-today

[Cerebus]

... 2400nm was unarmoured, 300nm armoured. ...

I don't think 2.4 micrometres of armour is going to make much difference. 

[bsdphk]

I doubt that cable is for sub-sea use, almost all such cables have at least one layer of steel, and much thicker envelopes.

No, they don't. A major design constraint is the need to fit as much as possible cable on a cable-laying ship, and that precludes steel armour.
[…]

The TAT-7 cable was steel core, […]

I didn't say "steel armour", I said "layer of steel", because you are quite right that at depth that is usually a steel "strength member" at the center of the cable.

The steel, or on a few very early cables: bronze, is necessary to prevent the length of cable hanging from the laying ship to the bottom of the sea from being stretched or pulled apart.

Air-dielectric coax-cables, like the one on the picture, has the additional weakness of a very fragile cross-section, which is why they were almost never used for sub-sea applications.

Summa summarum: The cable on the picture has no strength-member, steel or otherwise, and the very thin jacket offers insufficient mechanical protection against compression of the coaxial members, so that is clearly not a cable for sub-sea use.

In fact, I'm not even sure it is a cable for direct burial, it might be designed for use only in conduit.

PS: If you want to to read about the challenges of running coax under the Atlantic, the Bell Systems Technical Journal has excellent articles from the entire history of that practice.

[bsdphk]

That would depend on the age of the cable; there is no indication of that.

There are many indications of the age, notably a plastic sheath over paper insulated pairs and but plastic (rather than foam) disk coax.

I would say first half of 1960'ies.

The cable being UK Post Office and the post-war material scarcity means that it could be younger than that.

[mnementh]

And a quick video showing that more of the lamps in the display are now working:



(I need to get a camera that can close focus!!)

-Pat

That is effing amazing, Pat. What is the sampling "gate" time on that thing? Somewhere between .75 and 2 seconds it looks? Does not appear to be exactly fixed duration, either...

Ooooooh... you know something, Pat... they make LED dash panel bulbs in that base... 

No, wait... before you go looking for the lynching rope, hear me out. Those 328 bulbs are rated 6V; that means the unladen voltage is probably more like 7-8V. Should still be plenty for a 12V LED bulb. But here's the thing... running at considerably less current than those filaments, iffy contacts become much less of a problem, so might help in the long run.

And as a bonus... you can change the color... could have that luscious Emerald Green they're making now... or that deep pigeon's blood red like those old HP gear with the Siemens  (I think?) LED displays... or even orange to match all your nixies.   

mnem

[mnementh]

And a quick video showing that more of the lamps in the display are now working:

https://youtu.be/rBuoo5QtbDQ   (I need to get a camera that can close focus!!)   -Pat

As much as I enjoyed the video, I think you should stop making them... for the good of your TE ! 
You are too nervous when on camera, at the beginning you dropped the display assembly then tools soon after ! 
The health and well being of your TE comes first, our curiosity second.... which is satisfied anyway with the still pics...

Awww, Vince - Lay off the guy! He didn't make the vid for us; the furry kids made him do it! 

But yeah... really amazing what you can do with some ingenuity and the old grey matter. Just imagine today's engineers trying to figure that thing out... they'd spend the first 30 minutes looking for the Arduino. 

mnem
 

[TERRA Operative]

Bah, I just won a TDS220, with some parallel port only version of a comms module.
Paid equal to US$62, with some probe and a Japanese manual.

Lets see if it actually works when it arrives. 

If it doesn't you'll have your Japanese wife to answer to. 

Maybe i like the beatings.....  

Bah, I just won a TDS220, with some parallel port only version of a comms module.
Paid equal to US$62, with some probe and a Japanese manual.

Lets see if it actually works when it arrives. 

That's 4 or 5 times cheaper than here....I now understand why you moved to Japan... not because of the wife, but because of the dirt cheap TE, THEN only did you start looking for a wife locally, not the other way around ! 

That's.... not too far from the truth! Came to Japan for working holiday, stayed for the cool stuff then sealed the deal with a family.

[tggzzz]

For those in London hankering after some rare analogue goodness, there's https://www.bidspotter.co.uk/en-gb/auction-catalogues/ncm/catalogue-id-ncm-au10579/lot-8a8ff439-c79a-4e04-861f-aebe00b9affb

The listing was written by dyslexics; it is a Telequipment DM63 (not 65), i.e. a dual beam storage scope with 4 input channels. Despite my strong dislike of analogue storage scopes, mine actually works sufficiently well that I'm reluctant to flog it.

Now, do we know anybody in/near London who likes analogue scopes, and has some connection to Telequipment?

[mnementh]

Bah, I just won a TDS220, with some parallel port only version of a comms module.
Paid equal to US$62, with some probe and a Japanese manual.

Lets see if it actually works when it arrives. 

If it doesn't you'll have your Japanese wife to answer to. 

Naaahhh... at that price it's easy to justify. Even if he can't get it working he can part it out for profit, or parts mule it to make even more money on other units.

More likely she'd just ask him to take her out for sushi when it sells. 

mnem
 

[tggzzz]

... 2400nm was unarmoured, 300nm armoured. ...

I don't think 2.4 micrometres of armour is going to make much difference. 

Sigh. The other nm in common use all around the world, i.e. not just USA.

But you knew that

[bd139]

For those in London hankering after some rare analogue goodness, there's https://www.bidspotter.co.uk/en-gb/auction-catalogues/ncm/catalogue-id-ncm-au10579/lot-8a8ff439-c79a-4e04-861f-aebe00b9affb

The listing was written by dyslexics; it is a Telequipment DM63 (not 65), i.e. a dual beam storage scope with 4 input channels. Despite my strong dislike of analogue storage scopes, mine actually works sufficiently well that I'm reluctant to flog it.

Now, do we know anybody in/near London who likes analogue scopes, and has some connection to Telequipment?

That’s a hard nope from me 

[mnementh]

Yeah... yo momma come back just to    if you buy dat... 

mnem
 

[mnementh]

... 2400nm was unarmoured, 300nm armoured. ...

I don't think 2.4 micrometres of armour is going to make much difference. 

Sigh. The other nm in common use all around the world, i.e. not just USA.

But you knew that

So newton-metres then...?

mnem

[tggzzz]

I doubt that cable is for sub-sea use, almost all such cables have at least one layer of steel, and much thicker envelopes.

No, they don't. A major design constraint is the need to fit as much as possible cable on a cable-laying ship, and that precludes steel armour.
[…]

The TAT-7 cable was steel core, […]

I didn't say "steel armour", I said "layer of steel", because you are quite right that at depth that is usually a steel "strength member" at the center of the cable.

I wouldn't call a central solid steel core a "layer".

The steel, or on a few very early cables: bronze, is necessary to prevent the length of cable hanging from the laying ship to the bottom of the sea from being stretched or pulled apart.

Yup.

Air-dielectric coax-cables, like the one on the picture, has the additional weakness of a very fragile cross-section, which is why they were almost never used for sub-sea applications.

When I quickly looked at it last night it appeared that the core was solid, but broken with age and mishandling.

Looking at it now under good light, it does appear to be air cored with some plastic spacers at unknown intervals. The plastic isn't resilient any more.

Summa summarum: The cable on the picture has no strength-member, steel or otherwise, and the very thin jacket offers insufficient mechanical protection against compression of the coaxial members, so that is clearly not a cable for sub-sea use.

In fact, I'm not even sure it is a cable for direct burial, it might be designed for use only in conduit.

I'd be curious to know what conduit. I'm also curious to know why there are also PCQ wires.

The air core might well be a problem with subsea pressures.

PS: If you want to to read about the challenges of running coax under the Atlantic, the Bell Systems Technical Journal has excellent articles from the entire history of that practice.

I have Arthur C Clarke's "Voice Across The Sea" and "How The World Was One", which contain useful information.

I used to know the chap at GPO Martlesham Heath who designed grappling mechanisms used to retrieve deep ocean cables so they could be repaired on the cable-laying ships. Given the cost of running those ships, you want to be very sure that the grapple works first time!

[tggzzz]

... 2400nm was unarmoured, 300nm armoured. ...

I don't think 2.4 micrometres of armour is going to make much difference. 

Sigh. The other nm in common use all around the world, i.e. not just USA.

But you knew that

So newton-metres then...?

mnem
 

Got it in two.

[mnementh]

I knew the incredibly obvious answer would torque you off a bit. 

mnem
But in my heart, I was longing for nebulium.

[TERRA Operative]

Bah, I just won a TDS220, with some parallel port only version of a comms module.
Paid equal to US$62, with some probe and a Japanese manual.

Lets see if it actually works when it arrives. 

If it doesn't you'll have your Japanese wife to answer to. 

Naaahhh... at that price it's easy to justify. Even if he can't get it working he can part it out for profit, or parts mule it to make even more money on other units.

More likely she'd just ask him to take her out for sushi when it sells. 

mnem
 

Except I converted her to the ways of slabs of red meat. She eats sushi, but we imported a Weber barbeque (Genesis S-330, town gas version) and we use it a lot.

[bd139]

Yeah... yo momma come back just to    if you buy dat... 

mnem
 

Yes I am still emotionally damaged from the last two Telequipment ownership sessions.

[tggzzz]

That would depend on the age of the cable; there is no indication of that.

There are many indications of the age, notably a plastic sheath over paper insulated pairs and but plastic (rather than foam) disk coax.

I would say first half of 1960'ies.

The cable being UK Post Office and the post-war material scarcity means that it could be younger than that.

I'm sceptical that post-war material shortages might have been a driver of such highly specialised/expensive/important cable.

But your guess at the date is plausible, but not certain.

I doubt it would be earlier than the mid 50s. I doubt it would be the late-70s or later. By that time it was obvious multimode optical fibres were the future for comms between exchanges, and monomode fibre was the subject of much research. GPO Martlesham Heath was transmitting 2Mb/s down audio quad pairs between exchanges, which was the subject of some interesting and commercial and technical "considerations".

[Neper]

... 2400nm was unarmoured, 300nm armoured. ...

I don't think 2.4 micrometres of armour is going to make much difference. 

Sigh. The other nm in common use all around the world, i.e. not just USA.

But you knew that

So newton-metres then...?

mnem

Nautical miles?

[tggzzz]

Yeah... yo momma come back just to    if you buy dat... 

mnem
 

Yes I am still emotionally damaged from the last two Telequipment ownership sessions.

Sounds like my Tek 464 experience. By comparison my DM63 is exquisite.