Why can't you run a telephone extention cable next to a power cable?

Question

just wondering as it says you can't on the box?

Answer 1

It's all about "induced" AC hum, Trundle:

No physical harm will be done, assuming the AC line is in good shape and no sparking or arcing is going on. But, you may hear an annoying "hum" when you're on the phone. That hum is at 60 cycles per second, the frequency at which power is being applied to your house wiring. Which is to say, that the current is being sent to you 60 times a second. Which is also to say that 60 times a second, current is NOT being sent to you. If you were a housefly, watching your porch light, your eyes would see light-dark-light-dark ... 60 times a second (OK, 120 times a second, 60 times light, 60 times dark, etc.). We humans have brains that can fill in the blanks, as it were, so we see the light ONLY.

But all of this means that the on-off business can leak over to nearby audio lines which kind of vibrate along with the house current -and you hear it as "hum." Smack a low pitch tuning fork on the table, then put it on your skull -you'll get the idea.

I never pay attention to the instructions and install the damn lines wherever I want -if the hum is a problem, then I move the telephone cord. Another option is to wrap the phone cord in aluminum foil, which soaks up some of the leakage, but your friends will think you've packed a huge noodle for lunch.

The physical separation needn't be much -perhaps just an inch or two will do the trick.

So -experiment without concern over physical damage.

Hum a few bars and I'll see if I can fake it.

Answer 2

Two reasons.

The first reason is the electrical code, which says that low voltage cables (such as telephone) need to be at least 2" from power wiring for safety.

The second reason is to avoid electrical interference. If telephone wires are run close to power wires, they can pick up electrical noise and hum.

Answer 3

They don't get along well. They always fought as kids, and the power cable held a grudge, so it causes interference on the telephone wiring if it gets too close

Answer 4

ur power cable, there is a electric field around the cable, so when u pass another cable with a signal that is weak, it can create problems like signal loss, signal Noise etc

Answer 5

Power cables produce magnetic fields that can cause interference on your phone lines.

Answer 6

I'm with The South - the company on the box is just covering their ****!!

Answer 7

You'll get mains hum.

Answer 8

You will get the crap shocked out of you, if you do.

Answer 9

you will get interference on your phone.