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Trying to use dormant telephone wire through house walls for null modem/terminal stuff

NeXT

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That's what it was like in my old apartment. The upstairs and the downstairs didn't use landlines but all the existing wiring in the Vancouver Special routed to one exterior BCTel box. When I started using a Bluetooth to POTS bridge with my cellphone I just tied the lines from my bedroom to the patio together so that I could hear my phone ring while in the workshop and it didn't affect any other line in the house.
 

acgs

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Apr 24, 2022
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Well, the dormat telephone wire is more complicated than I thought. I wish I knew the history of the use by previous owners. The dormant telephone box on the back of the house has 3 lines in it, each with different landline telephone number written on it. There are 4 wall plates in the house (not 3; I miscounted), and one of them has 2 ports in it. When I tried using by telephone wire tester in several combinations of where the "master" module was and where the "slave" module was, the maximum number of lights I got was 1 on one of the numbered lines, and 1 on another of the numbered lines. The third line didn't light any lights.

How sophisticated is your phone line tester? Can it tell you if multiple lines are connected to the same port? You've already said that there are 4 wires in the phone lines. That means a possibility of 2 phone lines connected to each port. But, the RJ11/12 connector can have 6 wires (allowing 3 lines) hooked up to it. Knowing that 3 lines once came in, you might have some, not all, ports wired up to all 3 lines.

3 Lines, 4 wall plates (5 ports) = 21 possibilities. We can conclude the actual number is less due to your finding only 4-wires already. But, I think checking the hook up of all 5 ports individually is warranted. It could be that a private 3rd line was added to only "the den" or was "the teenage daughter's line." It's also possible that the dual port plate splits the 6 wires into a 1 line port and a 2 line port.

What the heck? The wires in the house wouldn't just disintegrate. Other than calling a telephone repairman and explaining my lovely eccentric idea to him on a house call, what can I do to find out more about the infrastructure I have, or thought I had? Is it possible an animal in the crawlspace chewed through the wires at some point in the past? Actually, that does sound like the most likely explanation, now that I think of it.

Agree with NeXT that this happens and with you that this is possibly the case here. But, I'd put it at the bottom of the list until all 5 port wire-ups are known.
 

Agent Orange

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Telco wires are normally paired Red-Green / Yellow- Black. Put a VOM between each pair and see if there's any voltage present. If not, you're probably good to go.
 

ldkraemer

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Chaffee, MO
We used to use RS-232C to 20ma Current loop converters to run across the various warehouse's
to get communications with the fiber delivery equipment. Engineers specified RS-232 for hundreds
of feet, and I knew better, so we ordered the Blackbox Converters. It was still working when I retired.
They have gone up in price, but someone has to have a similar unit cheaper.

Larry
 

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Bill-kun

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How sophisticated is your phone line tester? Can it tell you if multiple lines are connected to the same port? You've already said that there are 4 wires in the phone lines. That means a possibility of 2 phone lines connected to each port. But, the RJ11/12 connector can have 6 wires (allowing 3 lines) hooked up to it. Knowing that 3 lines once came in, you might have some, not all, ports wired up to all 3 lines.
My tester is a Master NS-468. It can test 6PXC and 8PXC.
 

Bill-kun

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Tomorrow I'm going into the crawlspace to trace the wires and see if any have been mangled by animals, corrosion, etc. That is the most logical thing to do at this point.
spcok.jpgrats.jpg
 

Bill-kun

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Update.

I had an electrician come and try to trace the phone lines. He went in the crawlspace and in the attic. In the end, it was a loss; he couldn't see any reason they wouldn't be working or lighting up. He suggested simply running two new lines of Cat5 through the house. The quote was over $500. I put it in the back on my mind.

Now, a couple months later, I am wondering about doing that, but more. I am wondering how the wires would be run if I wanted 4 or 6 lines of Cat7. (Nevermind the question of expense for now.) A bit of future-proofing, but also allowing me flexibility; since there would be many lines and they would be 8P8C, I could plug 6P6C or 4P4C into them as well and those would work. I could use the lines for whatever I want: actual Ethernet Internet, actual phone lines, vintage null modem, multi-room speakers, intercom, telegraph, or anything else. And 4 or 6 lines would give me the ability to use one line for one purpose and other lines for other purposes, all simultaneously.

The question is, how would these be connected? Would each line simply be unilaterally connected within itself?

For example with 4 lines (colors for illustration only):
1659543637364.png
  • My modern cable modem and router could be in room 1, giving Ethernet Internet through the green line and orange line to whatever one other device was on the green line in any other room, as long as it was only one other device (since there are no Internet switches in the lines themselves, only joint connectors at those 3 nodes). And the orange line could likewise supply any other one device with Ethernet Internet.
  • I could set up a vintage computer on null modem in every room on the red line, and then simply choose which vintage computer to send and which to receive (say, room 1 to room 2) simply by executing the null modem program on each, like File Maven. Then I could close File Maven on those two computers and go to two entirely different computers (say, room 3 to room 4) on the red line and send different files between those two.
  • If I wanted to add more vintage computers to the null modem network, I can loop the red line to the blue line in room 5, then connect 4 more vintage computers to the blue line in rooms 1, 2, 3, and 4.
Feedback? Does this make sense? Does it make the best sense for wanting several simultaneous different wiring purposes throughout the house?
 

Chuck(G)

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The way I do it is to home-run each line to a router/hub, adding hubs as necessary. You really don't want any impedance "bumps" in your lines--they can cost speed.
 

Eudimorphodon

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For example with 4 lines (colors for illustration only):
1659543637364.png

This topology doesn't make any sense. Branches in the lines like this are invalid for tech like Ethernet and even with analog phone lines will act as big antennas if they're not terminated.

Per Chuck's comment, the way to do this is to pick some room in your house (closet, basement, garage, whatever) to run all the to-each-room cables to, terminate them on patch panels:

How-to-Use-a-Home-Network-Patch-Panel.jpg


And then cross-wire things how you want them. For instance, you ran four lines to each room and wanted ethernet in every room you could wire the plug for jack #1 in every termination to an Ethernet switch connected to your Internet provider. Analog phones in rooms #2 and #5 could go through the next jack. (Run a jumper between the jacks on the patch panel to a splitter on the jack from the phone company.) Then, let's say, you wanted to run a null modem line between computers in rooms #3 and #4: you'd pick an unused jack in either room, and then in the wiring closet jumper the terminations together at the panel. IE, you treat it like an old time-y telephone switchboard.

This is how it's done these days; sometimes people skip the patch panels and just terminate all the closet lines with RJ-45 plugs intended to plug directly into an ethernet switch or whatever, but adding those panels gives you a ton more flexibility and also makes it a bit more durable. (Sucks to break off the latch on the male RJ-45 plug that's on the wire sticking out of the wall; it's a lot harder to break a jack and who cares if you mess up one of your patch cables.
 

Chuck(G)

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I terminate my runs in old-style 8P8C (RJ45) jacks individually, but then, my setup predates most of the fancy solutions we have nowadays--mine was a replacement for the RG58/U thinnet running between rooms. Days best forgotten, I think.

When I was doing some carpenter ant repair on the house's exterior, I had an opportunity to get at the between-floor parts of the house. I drilled holes in the top and bottom plates and stuck in a hunk of schedule 80 PVC and then left a length of iron wire with loops on either end inside the pipe,extending to the floors above and below. The idea was to locate the wire before I cut into the wall and then use it to thread cable through.

Still haven't done anything with it--many devices in the house are on WiFi, so the need for extensive Ethernet cable is less urgent. If I were to do it today, I'd probably run fiber.

Bill, have you considered ditching the dedicated cable idea and simply using Powerline adapters? Decent throughput and probably cheaper in the long run...
 

Eudimorphodon

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How well Powerline adapters work will depend a lot on your house wiring and the condition of your power outlets. I use one to supply an ethernet hub adjacent to a non-wifi-equipped network printer, and I end up having to unplug one or both ends of it every couple weeks to reboot it. (And it tends to be a little lossy and slow the rest of the time.)
 

DeltaDon

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Dutchess County, New York, USA
We did have a problem some 25 years ago in our old house with needing a phone connection in the family room for a DirecTV DVR's built-in modem and solved that with a send plus receive pair of devices that transmitted the phone signal over our 115 AC lines to get to a wired phone connection. I still have that pair stashed somewhere in our basement, I believe. Worked great for the daily or weekly updating the channel programs of the DVR. We got lucky with our new house, the "phone" lines to each room are wired with Cat5/6 and I could unplug as necessary from the telephone bus bar and directly connect a room to a 6 port switch and then on to the router. Our landline is a bunch of Panasonic wireless phones transmitting back to master connection and so we didn't need the wires for phone hookups.
 

mR_Slug

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UK
For example with 4 lines (colors for illustration only):
1659543637364.png
Please don't do this. Aside from electrical problems with like Ethernet, you have a maze of wires to deal with. And if something doesn't run right, you will constantly be worrying if your connections are good. As others have stated run it in a star configuration. For POTS, here, the standard was to daisy-chain each telephone socket to the next. Although you may find it splits into a tree because it was more convenient to wire it that way. If you are going to go to the trouble of running cat5 or 6 you may as well have it all terminating in one place.

What's your house made from? wood stick built? I have a solid brick house with plaster directly on walls. Now that is a real pain to re-do the electrical stuff. One thing that used to be common here was connection boxes hidden in the ceiling. They are a pain to trace, basically I'm rewiring everything. Makes me think of my electrical system when I see your diagram. You also have to consider the factor of what-did-I-do-10-years-ago when you are 10 years older and crouching down to a phone outlet and checking connections is harder than it is now.
 

Agent Orange

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Update.

I had an electrician come and try to trace the phone lines. He went in the crawlspace and in the attic. In the end, it was a loss; he couldn't see any reason they wouldn't be working or lighting up. He suggested simply running two new lines of Cat5 through the house. The quote was over $500. I put it in the back on my mind.

Now, a couple months later, I am wondering about doing that, but more. I am wondering how the wires would be run if I wanted 4 or 6 lines of Cat7. (Nevermind the question of expense for now.) A bit of future-proofing, but also allowing me flexibility; since there would be many lines and they would be 8P8C, I could plug 6P6C or 4P4C into them as well and those would work. I could use the lines for whatever I want: actual Ethernet Internet, actual phone lines, vintage null modem, multi-room speakers, intercom, telegraph, or anything else. And 4 or 6 lines would give me the ability to use one line for one purpose and other lines for other purposes, all simultaneously.

The question is, how would these be connected? Would each line simply be unilaterally connected within itself?

For example with 4 lines (colors for illustration only):
View attachment 1244462
  • My modern cable modem and router could be in room 1, giving Ethernet Internet through the green line and orange line to whatever one other device was on the green line in any other room, as long as it was only one other device (since there are no Internet switches in the lines themselves, only joint connectors at those 3 nodes). And the orange line could likewise supply any other one device with Ethernet Internet.
  • I could set up a vintage computer on null modem in every room on the red line, and then simply choose which vintage computer to send and which to receive (say, room 1 to room 2) simply by executing the null modem program on each, like File Maven. Then I could close File Maven on those two computers and go to two entirely different computers (say, room 3 to room 4) on the red line and send different files between those two.
  • If I wanted to add more vintage computers to the null modem network, I can loop the red line to the blue line in room 5, then connect 4 more vintage computers to the blue line in rooms 1, 2, 3, and 4.
Feedback? Does this make sense? Does it make the best sense for wanting several simultaneous different wiring purposes throughout the house?
All you need is CAT3 telco cable; Home Depot, Lowes, etc. Run a seperate line for each device and do not piggy pack. https://www.amazon.com/dp/B008X9YYVQ/ref=redir_mobile_desktop?_encoding=UTF8&aaxitk=a9d55740a539c7080a0e6df374196cb5&content-id=amzn1.sym.53aae2ac-0129-49a5-9c09-6530a9e11786:amzn1.sym.53aae2ac-0129-49a5-9c09-6530a9e11786&hsa_cr_id=5725309350801&pd_rd_plhdr=t&pd_rd_r=4ab511a2-fc84-4d97-89a1-84dfea4b8ccc&pd_rd_w=1xhcr&pd_rd_wg=uGYEb&qid=1659557987&ref_=sbx_be_s_sparkle_mcd_asin_0_img&sr=1-1-a094db1c-5033-42c6-82a2-587d01f975e8&th=1

Get a 66 block (or maybe one a little smaller) and a punch down tool and you'll be good to go. 6 wire cable serves no purpose in your instance. https://www.computercablestore.com/...st0u38lkgLQ-cCNe4oH5c__j9mqFDRUoaAjxuEALw_wcB
 

Bill-kun

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Messages
682
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Michigan
The way I do it is to home-run each line to a router/hub, adding hubs as necessary. You really don't want any impedance "bumps" in your lines--they can cost speed.
I'm not following. Would a modern router/hub/switch work for any kind of in-house signal, even a 2400 baud modem call?

I still have (and have offered for free) a pair of Diamond HomeFree Phoneline cards. Claim speeds up to 1Mbps...
Direct message sent. At the very least I want to find out what these are and do.

Bill, have you considered ditching the dedicated cable idea and simply using Powerline adapters? Decent throughput and probably cheaper in the long run...
This is the same sort of thing that the X10 1980s home automation stuff ran on, right? (See LGR's video for demonstration.) I can't say I've considered it, and I really don't want to try to rely on the electrical network of my house to send signals. Not because I think it would be unsafe, but my network is pretty cobbled together, with some walls of some rooms being on one circuit, other walls in the same room being on a different one, and at least two outlets that are double-fed. I had an electrician last month put a weather box on my outdoor front outlet, and he got shocked because the ground wire there was actually energized! They had to send a more skilled electrician on a second visit to solve that little puzzle.

What's your house made from? wood stick built?
Wood frame house with plaster walls, with an attic and a crawlspace. Built in 1959 with an addition in 1972.

Get a 66 block (or maybe one a little smaller) and a punch down tool and you'll be good to go.
After looking at pictures of what a 66 block is, no way do I want to do that much individual wiring! 🤯 I'd much rather just stick with whole cables and ports. Plus, I want each line to have 8 wires for any future repurposing.
1659566118309.png



Per Chuck's comment, the way to do this is to pick some room in your house (closet, basement, garage, whatever) to run all the to-each-room cables to, terminate them on patch panels:

How-to-Use-a-Home-Network-Patch-Panel.jpg


And then cross-wire things how you want them. For instance, you ran four lines to each room and wanted ethernet in every room you could wire the plug for jack #1 in every termination to an Ethernet switch connected to your Internet provider. Analog phones in rooms #2 and #5 could go through the next jack. (Run a jumper between the jacks on the patch panel to a splitter on the jack from the phone company.) Then, let's say, you wanted to run a null modem line between computers in rooms #3 and #4: you'd pick an unused jack in either room, and then in the wiring closet jumper the terminations together at the panel. IE, you treat it like an old time-y telephone switchboard.

This is how it's done these days; sometimes people skip the patch panels and just terminate all the closet lines with RJ-45 plugs intended to plug directly into an ethernet switch or whatever, but adding those panels gives you a ton more flexibility and also makes it a bit more durable. (Sucks to break off the latch on the male RJ-45 plug that's on the wire sticking out of the wall; it's a lot harder to break a jack and who cares if you mess up one of your patch cables.

Thanks. After having you explain it out like you did, this patch panel method is definitely better than my example--much more flexible and sensible. I think my laundry room would be the best place, especially since the circuit breaker box is there as well, and the outside telephone box is on the other side of the outer wall as well. So that means the laundry room panel would be the hub, and there would be 4 lines (iterating from my example) going from there to each of the 5 rooms (a total of 4*5=20 Ethernet cables in the walls). I would control what is connected to what simply by patching at the laundry room panel.
 

Agent Orange

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SE MI
I'm not following. Would a modern router/hub/switch work for any kind of in-house signal, even a 2400 baud modem call?


Direct message sent. At the very least I want to find out what these are and do.


This is the same sort of thing that the X10 1980s home automation stuff ran on, right? (See LGR's video for demonstration.) I can't say I've considered it, and I really don't want to try to rely on the electrical network of my house to send signals. Not because I think it would be unsafe, but my network is pretty cobbled together, with some walls of some rooms being on one circuit, other walls in the same room being on a different one, and at least two outlets that are double-fed. I had an electrician last month put a weather box on my outdoor front outlet, and he got shocked because the ground wire there was actually energized! They had to send a more skilled electrician on a second visit to solve that little puzzle.


Wood frame house with plaster walls, with an attic and a crawlspace. Built in 1959 with an addition in 1972.


After looking at pictures of what a 66 block is, no way do I want to do that much individual wiring! 🤯 I'd much rather just stick with whole cables and ports. Plus, I want each line to have 8 wires for any future repurposing.
View attachment 1244479





Thanks. After having you explain it out like you did, this patch panel method is definitely better than my example--much more flexible and sensible. I think my laundry room would be the best place, especially since the circuit breaker box is there as well, and the outside telephone box is on the other side of the outer wall as well. So that means the laundry room panel would be the hub, and there would be 4 lines (iterating from my example) going from there to each of the 5 rooms (a total of 4*5=20 Ethernet cables in the walls). I would control what is connected to what simply by patching at the laundry room panel.
Welp, that 66 block sure looks intimidating but not for your use. A punch down tool is about 9 bucks on Amazon. Go the cheapest route. Hey, I not blowing smoke your way, as I did this stuff with the feds for about 20 years.
 
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