Telephone wiring questions

[dlminehart]

I spent the bulk of my weekend getting my phones working again, after they suddenly stopped. PacBell tech came out with his fancy orange test phone, said the problem was in my internal house wiring, which was installed back in the early '60s using fiber-sheathed cable about 3/8" thick containing about a dozen strands.

I had trouble getting a second extension (star topology) going, and was unable to get a third, although I'd had three before. So, here are some questions I've been unable to find google answers for:

1) Is there a limit to the resistance (in the form of wiring and phones themselves) that can be attached to the incoming lines? I can measure the resistance over a length of wire, but how would I find out that of the phone itself?
2) Short of spending $70-$100 on a special test set, could I use a voltmeter to test the lines for shorts, splits, opens, live voltage, etc.? Tips for doing this?
3) Can I tie 4 lines (incoming plus 3 extensions) to the single screw-down attachment at my DSL splitter's voice side? Should they be twisted together before being screwed down? Or is that too many for a single attachment?
4) My splitter box has 4 unused screws; I was thinking of using these for two of the extensions, fed by wires from the Voice connectors. The latter would then have 3 wires (incoming, 1 extension, and jumper to the 4 screws just mentioned for the other 2 extensions). Is this reduction of 4 to 3 wires per Voice post worth worrying about?
5) Is there a significant advantage to using unshielded twisted pair (i.e., CAT3 or CAT5) wiring instead of the staight-through old style stuff, given my 3 50' runs?
Would my DSL benefit from using UTP wiring instead of the regular old phone stuff (same 50' run)?
6) Can anyone recommend a good booklet on phone wiring?

Thanks!

[LCHIEN]

I spent the bulk of my weekend getting my phones working again, after they suddenly stopped. PacBell tech came out with his fancy orange test phone, said the problem was in my internal house wiring, which was installed back in the early '60s using fiber-sheathed cable about 3/8" thick containing about a dozen strands.

I had trouble getting a second extension (star topology) going, and was unable to get a third, although I'd had three before. So, here are some questions I've been unable to find google answers for:

1) Is there a limit to the resistance (in the form of wiring and phones themselves) that can be attached to the incoming lines? I can measure the resistance over a length of wire, but how would I find out that of the phone itself? not really a problem
2) Short of spending $70-$100 on a special test set, could I use a voltmeter to test the lines for shorts, splits, opens, live voltage, etc.? Tips for doing this?see below
3) Can I tie 4 lines (incoming plus 3 extensions) to the single screw-down attachment at my DSL splitter's voice side? Should they be twisted together before being screwed down? Or is that too many for a single attachment?yes but normally those old houses use daisy chaining
4) My splitter box has 4 unused screws; I was thinking of using these for two of the extensions, fed by wires from the Voice connectors. The latter would then have 3 wires (incoming, 1 extension, and jumper to the 4 screws just mentioned for the other 2 extensions). Is this reduction of 4 to 3 wires per Voice post worth worrying about? whats a splitter box - are you referring to the network interconnect box on the outside of your house
5) Is there a significant advantage to using unshielded twisted pair (i.e., CAT3 or CAT5) wiring instead of the staight-through old style stuff, given my 3 50' runs?not really, analog phone lines don't carry more than 3000 Hz or so, Cat 5 is for 100,000,000 Hz. maybe some better hum rejection from the twisting OTOH, maybe your DSL will work better
Would my DSL benefit from using UTP wiring instead of the regular old phone stuff (same 50' run)?
6) Can anyone recommend a good booklet on phone wiring?

Thanks!

probably you need to step and eliminate. You probably have one bad phone mesing stuff up, cause they're all in parallel. Or one short circuit on one of your star legs.

Some simple methodical binary searching will probably find the problem.
Or even sequential testing.

Disconnect all four branches of your star. Connect only one at a time to the outside line from the telco. if it works, then make a note that its good, then try another, disconnecting the on you just tried until you either fins one bad or they are all good.
If you find one bad, then you have to replace the phone(s) one ata time on that branch.
If they're all good then you can add them one at a time until you have all four branches back on if it still works you're OK, if not, probably the last one added broke the back and it has a short or a bad phone on it.

Good luck.

[scorrpio]

I pondered on similar problems when I bought my house and phone wiring was a mess. Final decision: forgot I have that wiring, got voice via cable, and got a 5.8GHz expandable system. Main base plugged into cable modem, and I have 3 handsets in various house locations. (can expand to 8 handsets)If I stayed with regular phone service, I'd diconnect branches from main terminal, and connect the main base there. If I had DSL, I'd install the splitter at main terminal, plugged in the DSL modem there, and then installed a wireless router. The 2.4GHz WiFi and 5.8GHz phones don't interfere with each other.

[jseklund]

Ok, I spent 3 years selling phone systems, and I'm not a technician- but I am more technical than most. Here are my thoughts. (my numbers don't necessarily correspond to your numbers)

1. You probably have (or had) a house that is wired in a standard "loop" wiring situation. If you know otherwise, let me know- but if you don't know, this is a pretty safe assumption.

So, when things stopped working- did you run "home runs" back to some place to creat the star? If so, where did you run them back to?

2. As far as the limit to the # of phones on an incoming line- I have seen it stated before that there IS a power limit (most phones are powered by the phone lines, and this and the resistance factor mean there is a limit I think). However, I have never run across this in real life- and 3 phones is most definately NOT the limit. I think what I saw was that usual house wiring will support something like 13 phones. This is probably a non-factor.

3. As for testing without a tester- there are a few options. You could actually get a tester at either Lowes or Home Depot for about $35. I forget which one of those two had it, but it's a Gardner Bender Multi-Purpose Wire Tracer. The only link I could find has it for $45-

http://www.doityourself.com/invt/u375550

But I got it at one of the two big box stores and I believe it was $35. Eitherway, it's been very handy for me.

The other way to check is with a LONG extension cord, and a multi-meter. You could do a continuity check by putting a bare wire into the extension cord, bringing it to the other ends of the wires, and using the muti-meter between the prong on the extension cord and the wire ends you have. I have never seen this done in phones, but I've seen an electrical engineer friend do it for electric wires, and I don't see why it wouldn't work with a phone line.

4. The "splitter box" that you are talking about is unclear. The way the wiring works, usually, is that there is a "Network Interface Box" outside of your house (usually). It is normally a GREY box made of plastic with a socket/hexagonal screw on one side. The lines come into this box, and then connect to another wire that goes inside your house, to a small brownish/creme colored box that will USUALLY be in your basement and will say, "Network Interface". This is not really what phone companies refer to when they are talking about a Network Interface Box, but the sticker will say the same thing on this box. From there, a normal looking phone line plugs into a normal looking outlet on the "Network Interface" box in the basement, coming from a rectangle shaped box. If you open up this rectangle shaped box, there is usually a set of 8 screws- two screws for each of the four colors- Red, Green, Yellow, Black. Normally, the Red and the Green going to be the pair for "Line 1" coming into the house, and yellow and black denote "line 2". You put the lines into one of these screw-down mechanisms to go to the phones.

Note: The two "red" screws both go to the same line, so if you screw an incoming line into the first red screw, and an outgoing line into the second red screw, they will be on the same signal path. This is true for every color pair of screws. You cannot, however, put a line into the black screws and expect it to pick up a signal from one of the "red screws".

Most of the time, they are daisy chained together, as LChien said. This means one line comes out of the red, one out of the green (1 pair) and that pair goes to the first phone outlet in the house, then from the first outlet to the second, and so on. This is not the star pattern you mentioned- it is a looped pattern. So, if outlet #2 isn't working- outlet 3 won't either. Finding the order of the outlets can be tough.

If you are going to do "home runs" back to this rectangular box, which it sounds like you may have done, then pull out all of the wiring that is there for the rest of the house. Then, you can put 3-4 lines into each screw if need be. Be careful though, those lines are more fragile than you think. Stripping the casing off the ends helps, and make sure you don't break the copper as you screw down- this happens from time to time.


5. As far as using Cat5- I normally do. I don't know if there is really a "benefit" per se. The reason I do though- I can run one wire to a place and have 4 outlets, or 4 lines, or whatever - right there. Since normal phone wire has 2 pair, and Cat5 normally has 4 pair....it's just less wiring and I have room to grow usually. In otherwords, I may want one phone there today- but tomorrow I may want to put a fax next to it, and I don't want to have to run another pair to do it. You can get Cat3 in 4 pair too....like LChien said, it doesn't really make a huge difference on the usability I don't think. It is more for future upgrades. You could also remove the phone line and put in a cat 5 plug in the future if you needed by using the cat5 wiring....I just like it because it gives me future options.

6. I think LChien's problem solving methods are where you should start.

A. Unplug ALL of the phones from the wall. Then, I would go outside and find the grey network interface box, use a socket and open it up. You will see a copper pair going into a device with a phone plug on it. Take a normal, wired home phone and plug it in there. See if you get dial tone. If you don't- then it's not in your house. (My bet is that this is probably an unneccessary step- because you seem to have 2 working phones- but I like to check the simple things first).

B. Go into your basement, and find the small box that says Network interface and unpug the telephone wire from it. Plug your standard wired phone into this box and see if you still get signal. If so, then you know you are good up until that point. Plug the rectangular box phone line back into the interface and check all of your outlet connections.

C. I would then go to each OUTLET in the house and make sure the ends are screwed down tight, the wire is not broken off under the screw, and that the connections at these points are generally working.

D. plug your wired phone into each one and see if there's dial tone. You may find one, or a set of outlets that don't have dial tone....if they're daisy chained then you probably have a break between one of those outlets and the last working one. Again, which one is the last working one can be hard to find...but maybe you can follow the layout of your house and figure it out....

I hope this helps, and isn't too confusing. I'm trying to give a little of the logic of how it's SUPPOSED to work, but it may not apply perfectly to what you are looking at. Some older houses just have screws on a block instead of having an enclosed rectangular box where all the lines meet. It's fun there because there are no color codes on the screws- you have to look at the colors of the wires.

Home Runs will be easier to diagnose than a daisy chain. If you have all of the lines looped together and you plug the toner into one, the sensor will pick up signal on all of the others- so the sensor becomes almost useless. What you can do though, is if you have a group of broken jacks- you can put the toner on one, and see if any of the other broken jacks get the signal. This would show which of the broken jacks are still connected by wires, and possibly help you find the breaking point- although if there's only one break, all of the jacks will light up and you will still gather no info.

Let us know how it works, what you find and what you need. I have seen a couple of books on wiring in Borders...but never read any. Sorry I can't really help there.

[JR]

Utility-grade telephone systems have been essentially unchanged, at the physical layer, since Alexander Bell's time. They were designed to operate for miles on very low quality cable, driving a number of phones (remember party lines?).

Your house wiring should be (although may not be) configured in a star arrangement from the demarcation point - the grey access box. Connect the incoming red to all of the reds going out to the extensions. Do the same with green. Isolate problems by connecting only one extension at a time.

1) Is there a limit to the resistance (in the form of wiring and phones themselves) that can be attached to the incoming lines? I can measure the resistance over a length of wire, but how would I find out that of the phone itself?!

This is not a practical problem. Don't worry about it.

2) Short of spending $70-$100 on a special test set, could I use a voltmeter to test the lines for shorts, splits, opens, live voltage, etc.? Tips for doing this?

This can be very complicated. If you know the pairs going to each location from the demarc box, you could disconnect them all, then tie each pair together, one at a time. Then measure for continuity accross that pair at the other end.

3) Can I tie 4 lines (incoming plus 3 extensions) to the single screw-down attachment at my DSL splitter's voice side? Should they be twisted together before being screwed down? Or is that too many for a single attachment?

There's no real problem with this and no practical issue with tying them together before being screwed down, after, whatever. If they're connected, they're connected.

4) My splitter box has 4 unused screws; I was thinking of using these for two of the extensions, fed by wires from the Voice connectors. The latter would then have 3 wires (incoming, 1 extension, and jumper to the 4 screws just mentioned for the other 2 extensions). Is this reduction of 4 to 3 wires per Voice post worth worrying about?

I don't understand this at all, David. It takes one pair of wires to make a phone line. You must hook up each side of that pair to each of the extensions, in parallel.

5) Is there a significant advantage to using unshielded twisted pair (i.e., CAT3 or CAT5) wiring instead of the staight-through old style stuff, given my 3 50' runs? Would my DSL benefit from using UTP wiring instead of the regular old phone stuff (same 50' run)?

No advantage for voice applications. If you're eventually going to want to connect 100BaseT or GigE you'd want Cat5. The DSL signal is designed to operate on phone wiring, so there's no real need to use Cat5, but it would eliminate most cross-talk problems encountered with cheap wiring.

6) Can anyone recommend a good booklet on phone wiring?

Sorry, no.

[knotley]

Try this for starters:

https://www.swhowto.com