Telephone wiring 101.

I don't think the splitter is really a splitter. My guess is it isolates line 1 from line 2 so red/green from the cable modem goes to one RJ11 and black/yellow goes to the other. You only have one line, so only the first one works. Just plug a real splitter into the leg that works. (These things aren't really splitters, but I'm using that word because you did). Phones are connected in parallel.

ble

el

at

est

rks

all

ast

by

and

rsa

Fox

the

res

rom

res

rd

the

ty?

Hi David.

Polarity shouldn't matter, as far as I know. Many telephone leads have the wires reversed. I discovered this many years ago when trying to use off-the-shelf telephone leads for a 1-Wire cabling system. 1-Wire needs 'straight-through' wiring while 'phones seem to work with either straight-through or crossed. If you look at the 'phone leads that you have on-hand (e.g. those leads that connect the 'phone to the wall socket) I would be surprised if some of these were not crossed. One other point to bear in mind is loading. Each device loads the telephone network, if I might describe it as such. As far as I know a standard telephone end-use system is designed to work with a load of up to four units where a unit is a theoritical 'phone load. Any individual telephonic device may have a load of several units. For instance a particular 'phone (perhaps with fax an/or answering machine) might provide a load of 2 units. The loads of all 'phone type devices need to be added to get the total load. It is easy to forget modems in PCs and the like. Just something to bear in mind should you get your wiring sorted out.

Take care.

Mike

Hi Mike,

As I pointed out, the polarity did matter because system #2 did not work until I reversed the wires in the phone jack. Regarding the load on the line, does a portable phone system which has its own power supply place the same amount of load on the line as a stand-alone telephone?

Thanks for your reply.

Hi David, I tried posting yesterday, but never saw my post. To answer your recent question, only the designers know the load placed on the line by a phone. However, they usually list it somewhere as the REN or ringer equivalency number. 1.0 is the same as an old fashioned phone. Newer phones are often less than 1.0. The ringer is the only thing that matters when the phone is not being used to talk.

What I said yesterday that you may or may not have seen is the thing you call a splitter is probably not a splitterat all. If the jack on the modem allows for 2 lines, they probably use the middle two wires for line one (often associated with red and green wires) and the outer two wires for line two (often yellow and black). The "splitter" thing connects the middle two wires from the jack to the middle two of one output (line 1). It then connects the outer two wires to the middle two of the other output (line 2). If you want multiple phones on one line, only use the one output of the "splitter" thing. Get another dual adapter to connect multiple phone to that one output.

Pat

David Farber, regarding your phone wiring confusions, I have some comments.

Firstly, what is a "splitter"? That's not any kind of electronic component I've ever heard of. Is is a multiplexer? A joint? A wire-pairs separater? Or something else completely? Try checking it with an ohmmeter, or read the manual if you have one, to find out what it really is.

Secondly, yes, polarities often get switched in phone wiring, sometimes

Thirdly, don't trust wire colors, those change too, sometimes *several* times between the service entry and the telephone. (This, and the polarity swapping, are because phone cables tend to be "dropped" from the attic into the walls as separate snippets, and pasted together in the attic. So a blue/white pair from the entry might become orange/white, then green/white, then white/purple by the time it gets to your phone.

Fourthly, don't assume that because you get a dial tone, you have the wire-pair you think you do. Call your own phone number. If it rings, you do *not* have the right wire pair! You're illegally stealing service from someone else instead. Instead, try other pairs until you find the pair and polarity that not only gives a dial tone, but also gives a BUSY SIGNAL when you dial your own number. That's your pair. This is especially true in apartment buildings and businesses, but can even be a problem in single-family homes, if multiple lines (some possibly no longer in use) are installed.

Once I accidentally tapped into a pay phone that way at my apartment building. Since the service entry is in the rear, and the pay phone is out front, the installers ran the wires through my bedroom. Interestingly, I was able to make phone calls without paying the $0.75 the pay phone normally charges. I disconnected it immediately, though, both to stay out of trouble, and because it wasn't the line my DSL was coming in on.

One aspect I can comment on is, around here (other side of the country from you) I've seen the blue/white pair used for a separate line in a single household. That would be Line 2, and Line 1 would be the common red/green pair.

Much of the newer phone hookup wire is 4 pairs, instead of the conventional, decades old, 2 pair.

All of the lines should be connected inside of a network box (possibly outside), but there may be other junctions between the wall jacks and the network box.

There may be a jack and a pigtail cable to screw terminals, for each line in the network box, at least that's the way they're made around here.

The other items, I'm unfamiliar with.

-- Cheers, WB .............