5 ms·

Sorry should have been more clear; I'm an eletronics engineer so I know what crosstalk is, it's just that I didn't understand how this would be an actual proble

by stinos 6y ago

Sorry should have been more clear; I'm an eletronics engineer so I know what crosstalk is, it's just that I didn't understand how this would be an actual problem with CAT5. Phone line, that's something else though. If an electrician had done it, it likely would have been 10 or 20x more. Hmm, that is like twice the amount one would typcially pay here. Still, don't froget the working hours you put in there :) plus the fact that usually technicians get their materials for cheaper than you do (also because in my case it's only 6% VAT instead of 21%). I did many such calculations when renovating and for some things it was actually cheaper to get a technician.

ur-whale 6y ago
They're maybe getting it for cheaper than you do, but if you think that's what they're actually charging you, you're deluded. The typical electrician gets it indeed for cheaper than market rate, then charges it to you retail rate plus 20% to account for the "trouble" of sourcing and purchasing it.
- stinos 6y ago
  if you think that's what they're actually charging you, I never claimed that. The typical electrician Maybe you rather mean 'the typical electrician I met' or so because I know for a fact the rest of that sentence does not apply to the ones I met myself.
- parliament32 6y ago
  From my experience in trades, you just double the price of all materials.. which conveniently is roughly the same price homeowners will see if they spot-check at Home Depot.
baybal2 6y ago
Indeed, UTP5 is more or less crosstalk immune within for practical uses, STP5+ moreover so.
petre 6y ago
That's an easy one. Switch on the light, network disconnects. We had this happen at our office. There's obviously much more happening on an electrical network other than 50/60 Hz, like transient response to switching loads on and off, RF noise from spark loads, dimmers etc.
- Thlom 6y ago
  In digital cinema the projector and the playback server does a handshake and key exchange before you can play encrypted content.The rest of this story might not be entirely correct, I've been out of the business for a few years and this happened maybe 5-6 years ago, but it's a bit fun and kind of relevant. This usually works without any issues, but on one type of projector they had used a non-shielded network cable internally in the projector and if the projector lamp was lit juuuust at the right moment, the handshake would fail and the film would not play. Normally it wouldn't be a huge deal as the handshake happens just before the film and the lamp is usually lit on the beginning of the show long before the film starts. HOWEVER, there was this one cinema chain that had standardized their playlists in such a way that they for some stupid reason turned of the projector lamp in between the trailers and the film (I think to "introduce" the film) and then turned it on again just before the film with the result that the handshake failed 3 out of 10 times or so. Long term solution was to replace the shoddy cable. Short term solution was to change all their playlist templates to blind the lamp instead of turning it off. Like they should have done to begin with.
- stinos 6y ago
  Never had this myself for network, but I can imagine if the wires are close enough together and the light switch sparks enough (or draws enough power) it could happen. Actually this is our 'standard' way of intentionally messing up serial or USB communication: place wire next to the serial line, then try to generate as much transients as possible to induce errors in the bit stream. Still doesn't always work.
WalterBright 6y ago
> technicians get their materials for cheaper than you do Sure, they buy materials wholesale, but they bill you full retail for it. I installed around a mile of wiring :-) But I also got it exactly the way I wanted, the wires run where I wanted, and I bought professional quality tools to do the work, and still have/use them. I like working with my hands now and then, it's viscerally satisfying in a way a keyboard never is.
WalterBright 6y ago
> I didn't understand how this would be an actual problem with CAT5 I know that twisted pair is supposed to be resistant to that, but I wasn't going to risk it and didn't have a good way to test it. I didn't want even a teensy bit of hum, and there isn't any :-)

by stinos 6y ago

ur-whale 6y ago

They're maybe getting it for cheaper than you do, but if you think that's what they're actually charging you, you're deluded. The typical electrician gets it indeed for cheaper than market rate, then charges it to you retail rate plus 20% to account for the "trouble" of sourcing and purchasing it.

stinos 6y ago
if you think that's what they're actually charging you, I never claimed that. The typical electrician Maybe you rather mean 'the typical electrician I met' or so because I know for a fact the rest of that sentence does not apply to the ones I met myself.
parliament32 6y ago
From my experience in trades, you just double the price of all materials.. which conveniently is roughly the same price homeowners will see if they spot-check at Home Depot.

baybal2 6y ago

Indeed, UTP5 is more or less crosstalk immune within for practical uses, STP5+ moreover so.

petre 6y ago

That's an easy one. Switch on the light, network disconnects. We had this happen at our office. There's obviously much more happening on an electrical network other than 50/60 Hz, like transient response to switching loads on and off, RF noise from spark loads, dimmers etc.

Thlom 6y ago
In digital cinema the projector and the playback server does a handshake and key exchange before you can play encrypted content.The rest of this story might not be entirely correct, I've been out of the business for a few years and this happened maybe 5-6 years ago, but it's a bit fun and kind of relevant. This usually works without any issues, but on one type of projector they had used a non-shielded network cable internally in the projector and if the projector lamp was lit juuuust at the right moment, the handshake would fail and the film would not play. Normally it wouldn't be a huge deal as the handshake happens just before the film and the lamp is usually lit on the beginning of the show long before the film starts. HOWEVER, there was this one cinema chain that had standardized their playlists in such a way that they for some stupid reason turned of the projector lamp in between the trailers and the film (I think to "introduce" the film) and then turned it on again just before the film with the result that the handshake failed 3 out of 10 times or so. Long term solution was to replace the shoddy cable. Short term solution was to change all their playlist templates to blind the lamp instead of turning it off. Like they should have done to begin with.
stinos 6y ago
Never had this myself for network, but I can imagine if the wires are close enough together and the light switch sparks enough (or draws enough power) it could happen. Actually this is our 'standard' way of intentionally messing up serial or USB communication: place wire next to the serial line, then try to generate as much transients as possible to induce errors in the bit stream. Still doesn't always work.

WalterBright 6y ago

> technicians get their materials for cheaper than you do Sure, they buy materials wholesale, but they bill you full retail for it. I installed around a mile of wiring :-) But I also got it exactly the way I wanted, the wires run where I wanted, and I bought professional quality tools to do the work, and still have/use them. I like working with my hands now and then, it's viscerally satisfying in a way a keyboard never is.

WalterBright 6y ago

> I didn't understand how this would be an actual problem with CAT5 I know that twisted pair is supposed to be resistant to that, but I wasn't going to risk it and didn't have a good way to test it. I didn't want even a teensy bit of hum, and there isn't any :-)