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I have a 302 telephone that was manufactured in 5/39 (May 1939). The line cord does not have a four-prong connector attached; the wires are simply cut.

I am trying to get this connected. I have a four-wire RJ11 cable with both tip and ring (red and green) as well as yellow and black. The 302 has only green, red, and black.

I don't really have the equipment needed for stripping cables, nor do I want to. I am attempting to make a head on connection, like so:

The three wires

The yellow wire is hidden behind the green cable. The twistie ties are just to keep the individual copper wires together and straight. What I would like to do is be able to simply attach the three sets of wires to the RJ11 connector, and maybe tie it together with a larger twistie tie.

Currently, the interior of the telephone seems operational. There is only one unconnected wire as far as I can see, by the rectangular gray thing.

302 Telephone internals

I have been looking at several wiring schematics. One person said to connect green to green and red and yellow to red. A YouTuber had similar advice for a 500. But this was to connect to a two-wire RJ11 cable, and I have a four-wire RJ11 cable here.

I think ideally one would strip the RJ11 cable and then tape the right sets of wires to the wires in the RJ11 cable, but I'm not going to do that. I have been testing various combinations of colors, including G to G and R/Y to R. At the same time, I've been holding the receiver up to my ear but I am not getting a dial tone. The RJ11 cable is a live wire.

Does the wiring combination really matter? Will it not work if the combination is wrong? The wiring inside looks okay, so it's hard to isolate the problem.

The wiring in my 302 does not seem to be the same as the diagram in the answer:

Wiring of the 302

Could the red wire that is disconnected be causing a problem? Red is RING, so will it stop me from getting dial tone also?

When I did tip and ring to tip and ring it did not work:

Tip and ring wire connections

Greenonline
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InterLinked
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  • Yellow/Green to green, Red to red. – R Drast Jun 15 '17 at 15:45
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    You really can't expect to hold the wires on to the RJ11 and have it work. – JRE Jun 15 '17 at 17:02
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    Either get a connection block as Spehro Pefhany says, or else get out your pocket knife and strip the wires on the RJ11 cable. – JRE Jun 15 '17 at 17:07
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    You strip the outside insulation that covers all the wires together, then you strip the individual wires. – JRE Jun 15 '17 at 17:53
  • Pocket knife. Stripping wire with a pocket knife is as easy as using any specialized tool I've ever seen. It isn't hard. I learned to do it when I was a little kid. Surely an adult can manage it. – JRE Jun 15 '17 at 18:14
  • How to strip a wire with a knife. – JRE Jun 15 '17 at 18:17
  • How does stripping the end of the cable waste the rest of it? – JRE Jun 15 '17 at 18:18
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    Yeah, so. How's that a waste if you are using the telephone? You could also cut the cable somewhere in the middle and reconnect the two halves if you need it again. – JRE Jun 15 '17 at 18:27
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    No cables aren't free. But, you can reconnect the two halves just as easily as you connected your phone to one half. Twist and tape if you can't solder. Anyhow, enough of this. If a telephone patch cable breaks the bank, you've got more problems than I feel like dealing with. – JRE Jun 15 '17 at 18:33
  • @JRE I cannot reconnect two halves of a cable when one would be permenantely wired to the 302... am I missing something? Unless I encounter another phone in the future that needs this sort of work done, it would be wasted. Also, these are reverse, not straight, RJ11 cables – InterLinked Jun 15 '17 at 18:38

1 Answers1

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North American RJ11 cords can carry two phone lines. Red and Green are the wires normally used, with the outer yellow and black as the secondary. You would only use one pair, and not connect to the other.

Your phone diagram from here:

enter image description here

Green is TIP on the RJ11

Red is RING on the RJ11

So Red to Red, Green to Green.

Yellow should be grounded, according to the the diagram above. You can try the ground on an outlet box for the ground.

It's easier to wire (the question in your title!) if you can get a connection block like this one (preferably without the split plastic boss shown in the photo):

enter image description here

Spehro Pefhany
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  • See the diagram above. Yellow apparently needs to go to ground. – Spehro Pefhany Jun 15 '17 at 15:47
  • I looked at the diagram. I'm not sure what you mena by ground. Ground is for electrical, not telephone. I have 6 other telephones and none of them are grounded (they are all modular though). I don't know why I would do that with this. Can I just leave yellow out? Does it hurt to connect to green? Thanks, – InterLinked Jun 15 '17 at 15:57
  • I don't know what you mean by split plastic boss. Would this be alright? http://www.ebay.com/itm/172535143317 – InterLinked Jun 15 '17 at 16:01
  • I don't think you can hurt anything by misconnecting. Telephone circuits are very robust. You can try connecting it to red (ring). Here "ring" refers to the outer part of a jack, not to a ringer. – Spehro Pefhany Jun 15 '17 at 16:01
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    Yes, the ebay one looks the same. The one in my photo is broken from overtightening the screw for black. – Spehro Pefhany Jun 15 '17 at 16:03
  • Also, is the (crude) manner in which I try to force contact ok? I'm not sure if it is advisable to have my fingers touching the wires to hold them in place. If I took a scissors and cut the (disconnected) RJ11 connector off, could I just tie the wires together, or even try putting the RJ11 connector on? Is it okay to put plastic tape around them? Otherwise, I can't try calling the phone to test the ringer since the volts required for ringing could shock – InterLinked Jun 15 '17 at 16:05
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    In ancient times, with party lines (two customers sharing the same line), one customer's ringer would be connected between Tip and Goround, the other customer's between Ring and Ground. Fr single-customer lines the ringer is connected between Tip and Ring. – Peter Bennett Jun 15 '17 at 16:27
  • @PeterBennett The ringer is connected between T and R. Are you referring to the connection with the RJ11 plug or the wiring schematic above? (if so, what part), thanks – InterLinked Jun 15 '17 at 16:33
  • The wires look really corroded. If you just want to play with it you could try small wire nuts. The ringer will work through corrosion but you might find the sound distorted- copper oxides etc. actually form a crappy semiconductor (metal rectifier) at the metal surface. – Spehro Pefhany Jun 15 '17 at 18:14
  • @SpehroPefhany I'm thinking of doing a connector block like you suggested. I have 3 500s, 2 of which I prefer for making calls to this 302 anyways, since the dial needs to be lubricated as well and I don't know how to do that on the 302, but I would like to at least know I can use it if I have to. If I use a connector block, will corroded wires be a problem? Note the wires also have string intertwined with them for whatever reason. And the wires are more than 78 years old – InterLinked Jun 16 '17 at 12:28
  • @InterLinked Probably not if you tighten down the screws well. I have a little fiberglass tip pen that I use to clean oxidation off metals. Sort of like this one. – Spehro Pefhany Jun 16 '17 at 17:37