The city told me it is Century Link. But is it Fiber Optics, POTS or Coax???
Any help appreciated!
here’s the pics:
http://postimage.org/image/lulfson4f/
+closeup:
It looks like a plain old fat POTS cable - probably 100 pair. The fat thing near the pole is an “aerial service terminal” or just “splice case” used to break out a couple pair to make the drops to individual houses.
Thanks so much for your help! So that makes it an unshielded bunch of 100 twisted pair wires, correct? I’m interested to know the EMF radiation that would come off such a thing…
You mean RF radiation, and, given that it isn’t cooking anything in the vicinity, it isn’t very much. The sun is giving off more, even through all those clouds.
Pretty sure if its copper then its sending electricity rather than radio frequencies…I thought they don’t generally use copper for radio - that’s more coax?
The fact that the pairs are twisted makes any “EMF radiation” minimal.
But, I understand that a tinfoil hat provides 100% protection.
The closely-spaced cable support loops on the second picture (between the pole and the camera) are a dead giveaway. That’s a multipair (POTS) cable*. It may even be lead-jacketed, as that was the original reason for the excessive number of support loops. The later cables had plastic jackets and either pulp (paper) or plastic wire insulation and weighed a lot less per foot. Newer installations will have either a single or pair of stainless steel wires spiraled around the cable jacket and messenger, or sometimes (depending on the telco) have an integrated messenger in a figure-8 configuration.
Lead jacket can have either cotton- (with a really annoying “color code” involving different patterns using only red and natural colored thread) or pulp-insulated wires. There was a lead jacket cable with plastic wire insulation, but generally used only in low pair counts when transitioning from lead to plastic jacket sections.
I also see what might be a pressure stop between the pole cross-arm and the splice boot. That’s the slightly thicker piece where the other cable crosses between the poles. Those were used on the older parts of the system (which were pressurized to keep water from getting in and shorting out the cotton- or pulp-insulated wires). Newer parts of the system are plastic on plastic and don’t need to be pressurized, so it is easier to isolate pressure within the older parts of the system and not worry about seal integrity on the newer parts.
By the way, that’s what the nitrogen tanks you see on NYC sidewalks (with hoses going into manholes) are doing - they’re adding pressure on sections that are leaking badly enough that the central office can’t maintain sufficient pressure from there.
- Note - that style of loops was also used on power cables (also in lead jacket), but the splice boot in this picture proves that it is telephone, not power.
The EM field off such a cable is very weak. The field coming off your dishwasher or treadmill would be much stronger, when those appliances are in use.
the type of electricity in that phone cable does not leave the wire. the phone company couldn’t have long distance calls if it did.
radio and tv stations do want their signals to radiate.
Where did you get that? Yes, twisting the pairs REDUCES the amount of stray EM radiation coming from the wires, but it does not ELIMINATE it entirely.
How do I know this? Because I used to run error tests when I was a Uverse technician for AT&T. Sometimes the Uverse signal would get degraded by “crosstalk” from another wire next to it in the bundle. Usually this was from a DSL internet line, actual POTS signals are not as strong as DSL.
Whenever there was significant “crosstalk” on the line, it causes errors that showed up on the test results that were categorized as crosstalk.
yes there is crosstalk. for the concerns of the OP and the concerns of most people, the phone cables contain the signal. the technical details of electricity and electronics might have some other specifics which have meaning within the infrastructure of the system.
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Sometimes the Uverse signal would get degraded by “crosstalk” from another wire next to it in the bundle. Usually this was from a DSL internet line, actual POTS signals are not as strong as DSL.
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To be fair, my uncle Alexander could not have dreamed of pushing 8 MHz signals down a twisted pair for VDSL service, so it’s no big surprise (to me, at least) that the VDSL signaling leaks out a bit.
But it’s certainly nothing that’s going to affect humans unless they swallow the wire. 
Oh, absolutely. I agree with that. I just wanted to dispel the false notion that there’s NO electromagnetic field outside the wire itself. Of course there is, because there’s no metal shielding in there.
In terms of practical reality, though, it’s only the outside wires in a bundle that could cause an EM field outside the bundle. The EM field that the inner wires could produce would be blocked by the outer wires. And these are REALLY weak fields we’re talking about here, many times weaker than a dishwasher motor produces.
Well, data transfer rates have an exponential growth just like computer processor speeds do, but I wouldn’t expect the average phone linemen to know that. What year did your uncle retire?
Believe he retired from the craft somewhere in the 30s, so he was working the wires before the word “data” meant anything to the average person.
Wow, I figured he had retired in the 80s or 90s.