Noisy phone land line (hissing) and line wiring question.

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  #1  
Old 06-04-19, 04:20 PM
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Noisy phone land line (hissing) and line wiring question.

I get noise - hissing sound. Random. Ok for months, then every 2 or 3 days, then OK for weeks..There's a box on the outside of the house where I can plug in a phone. There is no noise there. So problem is inside the house. Picking up noise somewhere.

My incoming shielded cable is grounded. Also, there is a terminal block beside my breaker panel to which these incoming 4 wires (and ground) attach to this block.
I have 4 phone cables coming down from the ceiling joists to this block. I plan disconnect one phone line at a time to check for noise. Slight problem doing this:
All reds are on one screw of terminal block. All greens on another screw. All yellows attach to the same terminal as the ground.??? All blacks from my 4 phone wires are all connected together with a wirenut. Blacks are not attached to terminal block.???
SO, I'll have to disconnect everything to separate the 4 lines.

I realize the yellow and black aren't used, but why are the yellows connected to the ground?
After I separate everything, should I re-connect the yellows to ground? Why?
Is this weird wiring causing my noise?
 
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Old 06-04-19, 06:59 PM
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It's possible that something inside one of the phones is connected to the yellow wire. That would introduce a ground to the phone that it cannot use. Some phones are two lines in one cord. At the demarc block...... only red and green should be connected. The yellow and black wires don't need to be connected together or to anything. Usually they are just left aside to be used for a second line.

Typically..... any introduction of ground on the phone line will cause noise.
 
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Old 06-04-19, 07:31 PM
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UPDATE:
Yeah, I was thinking ground. Or, might be a "whisker" between 2 wires (bare wire ends) in a wall. I've seen electronics fail because of an apparent strand of dust.

Anyway, I've got all 4 wires of the 4 lines separated with an additional terminal block. Nothing connected to ground, except the shielding on the cable.
So far, so good. At least I can easily disconnect one circuit now.

EDIT: And thanks for the heads-up about 2-wire cords. Could be easy fix.
 
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Old 06-05-19, 02:32 PM
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Premise wiring for a Party Line needed a ground at the sets and the yellow was often grounded for that purpose.
 
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Old 06-05-19, 07:04 PM
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Excellent point.

I haven't seen an active party line since I can remember but that could be different in rural areas.
 
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Old 06-06-19, 08:04 AM
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Telephone lines are pretty much the same as 100 yrs ago. Telephones has changed, we have got more sensible electronics, and the surroundings has changed. A good old telephone without any battery adapter etc are less sensible, and a wireless phone may be in the other end.

You should use one pair of wires, and those 2 are twisted around each other, this is to reduce noise from the surroundings. Yellow and black could be used as a 2. pair, or yellow for ground and black for power to lighted dials on e.g. the princess telephones. You may do whatever you want to do with them.

Since this is periodic, is it something you may notice that you are doing, running a washing machine charging a battery etc???
 
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Old 06-12-19, 07:00 PM
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UPDATE:
Arrgh. Thought I had it fixed. I attached all wires where it enters the house - separately. Gr to Gr, Red-Red, Blk-Blk, Yell-Yell. All on a new terminal block. No more yellow to ground. Was OK for 3 days. Then hissing came back. Seems it's on windy days.
So I'm slowly checking that all phones in the house are 2-wire only. Now I'm clipping the Blk & Yell on the bracket the phone hangs on. Haven't got all of them yet.
Somewhere, I assume there is a Black or Yellow picking up noise. Looks like I'll have to check behind the wall wherever there is a phone plug or connection.

Haven';t disassembled any phones yet. Hadn't thought of that. Might be my next project.
 
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Old 06-12-19, 07:52 PM
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The problem could also be outside the house. Water in the trunk cable on the pole can cause noise. The problem is.... if it's only intermittent.... the phone tech will have a hard time locating it.

In order to completely eliminate the wiring in your house..... connect a phone directly to the block with the house wiring disconnected. If the problem is still there.... it's outside.
 
  #9  
Old 06-16-19, 11:56 AM
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What kind of phones do you have connected? I have used a setup for measuring my line as this: http://www.classicrotaryphones.com/f...ch=43586;image Ring= red Tip= green When I measured to ground, I just used ground on a grounded power outlet.

The reason for the 148 ohms resistor was because I had that size you may use anything from 100 to 330 ohms,

When I sent this together with a complaint the telco found a wire from another line touching a wire from mine. (I'm in Norway)
 
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