Products > Test Equipment
Test Equipment Anonymous (TEA) group therapy thread
Cerebus:
--- Quote from: tggzzz on June 27, 2022, 09:52:25 am ---... 2400nm was unarmoured, 300nm armoured. ...
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I don't think 2.4 micrometres of armour is going to make much difference. >:D
bsdphk:
--- Quote from: tggzzz on June 27, 2022, 09:52:25 am ---
--- Quote from: bsdphk on June 27, 2022, 08:20:03 am ---I doubt that cable is for sub-sea use, almost all such cables have at least one layer of steel, and much thicker envelopes.
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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, […]
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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:
--- Quote from: tggzzz on June 27, 2022, 09:52:25 am ---That would depend on the age of the cable; there is no indication of that.
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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:
--- Quote from: Cubdriver on June 27, 2022, 07:57:09 am ---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
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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... >:D
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. ;D
mnem
mnementh:
--- Quote from: Vince on June 27, 2022, 08:27:59 am ---
--- Quote from: Cubdriver on June 27, 2022, 07:57:09 am ---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
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As much as I enjoyed the video, I think you should stop making them... for the good of your TE ! :-DD
You are too nervous when on camera, at the beginning you dropped the display assembly then tools soon after ! :scared:
The health and well being of your TE comes first, our curiosity second.... which is satisfied anyway with the still pics...
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Awww, Vince - Lay off the guy! He didn't make the vid for us; the furry kids made him do it! :-DD
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. >:D
mnem
:-DMM
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