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Test Equipment Anonymous (TEA) group therapy thread

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vk6zgo:

--- Quote from: tautech on June 28, 2022, 01:53:34 am ---
--- Quote from: vk6zgo on June 28, 2022, 01:38:50 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.

But it is not a trivial cable either: It could transfer between two and thirty thousand simultaneous telephone conversations, depending on the route and repeater spacing.

--- End quote ---
It looks a lot like the terrestrial "coax cables" which were a big deal in Oz back in the early 1960s, before microwave links became widespread.

When the old PMG's Dept ran such a cable from Perth to Geraldton, back around '62/'63, They used the "direct burial system", & had a crew with several Cat D9s ripping a trench.

A large part of the route became  very "heavy going" for the ripper assemblies, which were lasting a lot shorter time than had been predicted.
After discussions, Cat sent an Engineer, who was "embedded" with the crew, & "burnt the midnight oil" a lot examining the damage to the rippers.
Ultimately, following his insights, Cat made some new ripper blades which did have the predicted life.

I wonder if they would go to such lengths today-----I somehow doubt it!

--- End quote ---
If it were for a ~400km trench(Perth to Geraldton = 373km straight line distance) you'd think so but these days an off the shelf microwave link solution would be way cheaper.....you just couldn't even get the machinery on the job for less !

--- End quote ---

They extended the coax to Carnarvon in the later '60s, but from there on, up to Kununurra, it was all an open wire pole route until the '80s when that run became all microwave, with a UHF spur off to Wyndham.

Nowadays, it is pretty much, "back to the future", with direct burying of optical fibre being "all the go", & microwave pretty much having disappeared, except in "niche" applications.

tautech:

--- Quote from: vk6zgo on June 28, 2022, 02:18:51 am ---Nowadays, it is pretty much, "back to the future", with direct burying of optical fibre being "all the go", & microwave pretty much having disappeared, except in "niche" applications.

--- End quote ---
Yes we're seeing that here too yet even for the semirural location where we are, a wireless solution is faster and cheaper to rollout decent connectivity to the masses albeit not with 1GB/s connections like in urban areas.

Out our ways most of the fibre is for backhaul and it passes many potential customers gates yet they don't get an option to connect to it.
I spent a year or so discussing this with the NZ manager of new HW rollout and while he was sympathetic the pre-existing last mile copper network was to remain for the foreseeable future.  :horse:
Absolutely no vision past immediate ROI from the providers.  |O

We jumped ship and went wireless with a Mom&Pop ISP.

mansaxel:

--- Quote from: vk6zgo on June 28, 2022, 01:38:50 am ---
A large part of the route became  very "heavy going" for the ripper assemblies, which were lasting a lot shorter time than had been predicted. After discussions, Cat sent an Engineer, who was "embedded" with the crew, & "burnt the midnight oil" a lot examining the damage to the rippers. Ultimately, following his insights, Cat made some new ripper blades which did have the predicted life.

I wonder if they would go to such lengths today-----I somehow doubt it!

--- End quote ---

Somewhere around 2004, we had a series of PSU failures in routers in the academic part of the Internet. After discussions, and at the insistence of the PSU OEM who could not understand why their design would burn to short so frequently (IIRC a MOV decided it needed to do a "kamikaze protection action") , they sent a couple engineers to investigate. We did a bunch of site visits, had a bit of a booze-up, and did some measurements and they came back with a protection scheme they wanted to implement; an external OVP. This was done at vendor expense and all supplies stayed alive.

Since we had a lot of routers at other sites not experiencing the problem, I still suspect a highly strung batch of MOVen. But that of course was out of the question...  |O

mansaxel:

--- Quote from: tautech on June 28, 2022, 02:52:02 am ---
Out our ways most of the fibre is for backhaul and it passes many potential customers gates yet they don't get an option to connect to it.
I spent a year or so discussing this with the NZ manager of new HW rollout and while he was sympathetic the pre-existing last mile copper network was to remain for the foreseeable future.  :horse:
Absolutely no vision past immediate ROI from the providers.  |O

We jumped ship and went wireless with a Mom&Pop ISP.

--- End quote ---

A long-haul network is very different from a last-mile one in so many ways. I am not surprised at all. For starters, connecting to it would require the optical equivalent of a cloverleaf interchange, an OADM. Not a practical CPE.

In the early coax / microwave years, they would not let you connect either. The pressurising equipment and the demultiplexing racks would also not be a practical CPE.

Also, all those schemes would be very bad for the long-haul signal quality.

Where opticks excel, is that they have much higher bandwidth for metro hauls than anything else, and at extremely low cost. 1,25 GBaud transceivers cost around 13€ a piece to me as an end customer. And they comfortably reach 20km over G.652 glass. But that requires a p2p link to the CO to be practical, not a drop from the long-reach fibre. (The next fool suggesting GPON will be dealt with!)

AVGresponding:


https://www.eevblog.com/forum/dodgy-technology/the-non-linear-plasma-reactor/msg4265899/#msg4265899

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