Classic Rotary Phones Forum

Telephone Switching => Key Systems (Electronic, 1A2 etc) => Topic started by: Babybearjs on January 19, 2021, 07:37:51 AM

Title: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on January 19, 2021, 07:37:51 AM
I'm trying to find the color coding for the older mounting cords on keysets prior to 1950-55. the color code had changed when the newer sets came out in the late 50's and I'm trying to find the old code. does anyone know if the TCI Library has anything on this? the old cords started out with RGBYBW (red, green, black, yellow blue, white) they had color combinations like Brown, Black, Red, White and Double colors (RR, GG, YY, BB) does anyone know about this history? I found the practice from 1961, 502-5254-404 that shows the mounting cord pinout.... (D30B) what I want to know is what was the OLD wiring code for the 25 pair mounting cords on the 560 series phones..... so far, I've just found the 15 pair pinout and don't know what order the colors went in..... on the new cables it goes White, Red, Black, Yellow Violet.... on the old ones..... brown, slate, red, black, white? its hard to figure out what they used to have... double colors also?? even triple color codes....thats what throws me....
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on January 19, 2021, 10:05:15 PM
I hope I get some results with this.... anyway, I posted a question yesterday about old color codes from the 1950's.... and found through Frank Harrels website, a partial answer... the first 5 pairs of the OLD color code.... RED, GREEN, BLACK, YELLOW, BLUE, WHITE, BROWN, ORANGE, PINK, and SLATE..... following that..... the Brown set.... BWN-Red, Bwn-Grn, Bwn-Blk, Bwn-Yel, bwn-Blu, Bwn-Wht, BROWN (Bwn-Bwn), Bwn-Org, Bwn-Pnk, Bwn-Slt.... (at least I think thats how it could have gone) so, does anyone know what the next color combination could have been? When I found the Pink-Slate wires, that answered the 5th pair question.... so..... does anyone want to comment on this, or am I just wasting my time?
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on January 29, 2021, 10:58:38 PM
Hmmm yes I have seen some of this old 25 pair solid color stuff when doing electrical work in old offices, never thought to save it.
I believe its based on
Tip +    Ring -
L1 green     red
l2 black     yellow
L3 white     blue
L4 brown     orange
L5 pink     slate
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on February 08, 2021, 03:34:41 PM
OK... so we have ID'd the first set, what about the other 4  color groups.  any idea?
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Key2871 on February 08, 2021, 04:18:20 PM
I thought I had information on some of the MD color codes, but I cant seem to find it in the house.
Anyway, can I ask John, why do you want them?
Are you working on these old key sets?
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: poplar1 on February 08, 2021, 09:10:22 PM
Here is a start: WE 564HD in TCI Library

BSP 502-541-406 issue 1

The leads are grouped together, such as all the tips and rings, but both the old color code and new color codes are shown side by side for each lead.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Key2871 on February 09, 2021, 12:01:15 PM
From what I see, it uses a 30 (D30B) conductor mounting cord.
John do you have this? Do you have BSP 502-541-406 ISSUE 2?
Because I have issue 2 and it also shows the old and new color codes. Key Service Manual Vol 1.
Be specific, do you need all the colors, termination etc.
Or do you have this BSP already so you can look it up.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: poplar1 on February 09, 2021, 02:16:16 PM
Here is the link to the BSP I cited:

https://www.telephonecollectors.info/index.php/browse/bsps-bell-system/bsp-categories-by-later-division-number-by-doc/500-529-station-equipment/502-division-station-sets-common-battery/2878-502-541-406-i1-service-564hd-telephone-set-tl?highlight=WyI1NjRoZCJd
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: poplar1 on February 09, 2021, 06:43:13 PM
It should be noted that while the diagram in the above BSP shows the mounting cord with 34 conductors with corresponding colors for both the old color code and the new one, these are both with an amphenol plug where the Tip-Ring, A(H), A1 (B1), LG, L for the first line are grouped together on pins 1-6. (Similar for the other lines.) However, in the hard-wired sets (using 44A connecting blocks), the lamp leads are grouped together separate from the T-R-A(H)-A1 (B1) leads.

For that reason, the 3rd pair of the old color code (White and Blue) are not found on pins 5 and 6 even though the old color code would logically be G, R; BK, Y; W BL.

Title: Re: Mounting Cord wire Color coding for older keysets
Post by: poplar1 on February 09, 2021, 06:54:44 PM
In order of the old colors (rather than the pins): -- not including the lamp leads

1. Green
2.  Red
3. Black.
4. Yellow

7. White
8. Blue
9. Brown-Green
10. Brown-Red

13. Brown-Black
14. Brown-Yellow
15. Brown-White
16. Brown-Blue

19. Red-Yellow
20. Red-Green
21. Red-Blue
22. Red-Black

25. Black-Green
26. Red-White
27. Green-Blue
28. Green-Black

I need to compare this to the diagrams for 464 sets to see if they are the same.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on February 09, 2021, 07:01:23 PM
Thank you for the info! that answers my question.... so the scheme could be applied to a 25 pair cable? this is what I came up with as far as the order the cabling could have been in, is there any documentaion to support my theory? this is all based on 5 pair groups.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Key2871 on February 09, 2021, 09:20:27 PM
I don't think the old color codes could be compared to the new in 25 pair cables, they might be similar but that's about it, from what I see.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on February 09, 2021, 11:37:49 PM
yeah, its funny to actually be able to piece the old scheme together.... I don't know how accurate it is, but it gives me a glimps into what was at one point.... I never knew that Pink/Slate was the 5th pair in the old scheme.... I remember seeing pink in a japanese phone, but just thought is was what they used.... so there must have been a regular color code back then for them to follow.... its just too bad the information is lost pretty much.... the only clue I have is the old BSP from the 60's showing the odd colors.... I would love to see the actual BSP showing the assigned wiring schemmmme of those days.... All I know is basic colors they used to use.... Red-Green-Black-Yellow-Blue-White... and in the old 3 wire station wiring of Red-Green-Yellow.... and the fact that in the 1900's to the 1940's they used to use twisted pair, normally black as IW in homes.... just like to old Tube and Knob wiring of that time..... Interesting history....
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on February 17, 2021, 10:47:43 PM
Well that nice to have documented, thanks for doing that.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on February 18, 2021, 01:07:42 AM
you are welcome. I don't know how acurate it is as there was very little information to go on. I was really happy when someone gave me the colors for the 5th pair..(pink/slate) once I had the first original pair colors, then I followed the base colors for the other 4 groups. once I found them, then I just put it together... I wish there had been more documents available, but they all seem to be lost to history.... Western Electric wasn't the only company making phone cords.... so if any other information comes to light, this is the best I can come up with.... I hope the order is right since its mainly based on the BSP 502-541-406 from the 1950s/1960's... because they did not have speakerphones until the late 1960's there are "Vacant" spaces in the wiring scheme. the most pairs I saw was 20.... which only gives you 40 wires....and of course, amphenol plugs didn't come to age until the 1960's as everything else was hardwired. a maximum of 4 #44 10 terminal blocks were used. prior to the 500 series phones being made, the 400 series was used and sometimes the didn't even have illuminated buttons.... the old 1A key system.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on February 20, 2021, 10:32:49 PM
Well thats even more of a reason to get this documented, so future collectors can resurrect 1A systems.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: poplar1 on February 21, 2021, 11:57:41 AM
Thank you for the info! that answers my question.... so the scheme could be applied to a 25 pair cable? this is what I came up with as far as the order the cabling could have been in, is there any documentaion to support my theory? this is all based on 5 pair groups.

1. You have tip and ring backwards for all the blacks. Tip is black, ring is yellow.
2. I find no evidence of a "pink/slate" pair anywhere
3. The designations for the right column (T R H B LG L) are correct for the current color code. However, on older sets, the lamp leads are separate from the T R H(A) B(A1) leads.
4. The colors for the mounting cord and the "inside wire" (cable from the Key Equipment to the telephone set) are the same in the current color code (W-B/B-W; W-O/O-W etc.) However, in the old color codes, the mounting cord and the inside wire are different.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Key2871 on February 21, 2021, 12:28:04 PM
I think perhaps the red faded to pink. Or another color faded to pink.
I've seen older wires that have faded to other colors, usually not real bad, but yes I have been there where it's hard to decifer the color because she had changed the original.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: poplar1 on February 21, 2021, 01:09:52 PM
                          TABLE B

Pair No.          Key Cable                                  Connecting Block
                 C Inside    D Inside              Term No.  Cord Cond     Block No.
                  Wiring       Wiring                                Color

1                 BL             BL                      1               R     
                   W              W                      2               G
                                                                                                   1 (Cord Butt)
2                  O              O                       4               Y
                   W              W                       5             BK

3                 G               G                        6             BL
                   W              W                       7              W

4                 BR            BR                       9             BR-R
                   W              W                      10            BR-G

5                  S              S                        3             BR-Y
                   W              W                       8             BR-BK
________________________________________ _________________________________

6                BL-W          BL                       1             BR-BL
                     W             R                       2              BR-W

7               BL-O            O                        4             R-G
                   W              R                        5             R-Y
                                                                                                           2
8               BL-G            G                        6            R-BK
                   W              R                        7             R-BL

9               BL-BR          BR                       9            R-W
                   W               R                       10           G-Y

10             BL-S             S                         3            G-BK
                   W               R                        8             G-BL
________________________________________ ____________________________

11             O-W            BL                        1             G-W
                  W              BK                        2             Y-BK

12             O-G              O                        4             Y-BL
                 W               BK                        5             Y-W
                                                                                                             3
13             O-BR            G                        6              BK-BL
                  W              BK                        7              BK-W

14             O-S             BR                       9               BL-W
                  W               BK                      10                 S

15             G-W              S                        3               S-R
                   W              BK                       8               S-G
________________________________________ ___________________________

16             G-BR           BL                        1               S-Y
                   W              Y                         2               S-BK

17             G-S             O                         4               S-BL
                  W               Y                         5                 -

18            BR-W            G                         6              S-W
                 W                Y                         7                -                      4 (Cable Butt)

19           BR-S             BR                       9               S-BR
                 W                Y                       10                 -

20            S-W              S                         3               BR
                 W               Y                          8                -
________________________________________ ____________________________

From C33.545 Issue 9, Feb. 1956, Connecting Blocks, page 26
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on February 21, 2021, 10:11:25 PM
 :) thank you for the update... that helps! and there is a BSP reference also! wonderful! Thank you....
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Dan F on February 22, 2021, 01:53:11 AM
Have fun everyone

attached pdf file I created some time ago
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on February 22, 2021, 11:45:24 AM
Thanks thats a nice PDF now we just need one with the old codes. :)
If I recall correctly;
Under layers and layers of abandoned cables in an old eye doctor office I was working on,  I did run across what resembles the 40 pair in a brown jacket.
It was something I had not seen. I should have saved a piece.

It would be interesting to see some photos of actual cables with these color codes.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: poplar1 on February 22, 2021, 05:21:49 PM
C33.545 issue 8 is in TCI library. Unlike my issue 9, issue 8 shows the cable colors for the first 76 pairs in Table A. The pre-1954 colors are in the column marked "Inside Wire C." The new 1954 colors  are for "Inside Wire D."
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on February 22, 2021, 06:08:23 PM
its interesting to read the BSP. the color code for the IW is still the same, though the line cords have been broiugh up to current standards..... I keep seeing "Double Red" and similar doubles in the list, how a tech could ever keep trak is  beyond me.... I have a few old multiconductor line cords and trying to ID them is hard, the colors are so faded with time that I can't even use them... the newer cords with the black jackets are easy to ID, though a pain to try to use... I just stay with the new suff on the old phones... its quicker... anyway, the whole idea behind this thread was to see if the inside wiring was the same as the Line cords and to find out if the Bell system actually had a pair registration (standarization) back then... and how it was used.... knowing the first 10 colors of ther old code gives one the foundation of what used to be, if it was in actual use, or just whatever colors they had available to them when making cabling... we know that WRBYV are now the standard.... but how did Brown come into play as a main color? Interesting.... and then what was the real color format back in the day.... seeing old paperwork shows that they used to use bell wire for phone jacks, and black at that.... just like the old Tube and Knob wiring of the time....  how they ever kept the T & R correct is beyond me.... just like the T & K, how did you know which wire was what without a ground reference... oh well, so much for history!
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Jim Stettler on February 24, 2021, 05:58:45 PM
or just whatever colors they had available to them when making cabling... we know that WRBYV are now the standard.... but how did Brown come into play as a main color?
My understanding was they used the most colorfast colors available at the time. Fading was taken into account for selecting colors to use.
Brown has been a standard colorfast color for a long time in the telephone industry.
On old 25 pair cable they also had a 26th pair for a spare.
Jim
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on February 28, 2021, 11:26:17 PM
yeah,m and thenn they updated the code.... oh well.... anyway, thanks everyone for chiming in! it has been very interesting hearing from all of you on this subject!
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on March 02, 2021, 02:07:11 AM
My understanding was they used the most colorfast colors available at the time. Fading was taken into account for selecting colors to use.
Brown has been a standard colorfast color for a long time in the telephone industry.
On old 25 pair cable they also had a 26th pair for a spare.
Jim
What are or were colorfast colors?
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on March 02, 2021, 10:33:13 PM
I would think they were colors that wouldn't fade over time... on the old cloth covered line cords the colors faded with time and were impossible to see... so the sets would have to be upgraded... the old sets were sent back to WE for refurbishing and new cords were put in.... this mainly applies to the old 400 series sets... I've had to toss old cords because they were too faded and didn't tone out when tested.... broken conductors... I kind of with OPW could make cloth covered 25 pair cables... those would be neat to see on the old 400 series sets....
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on July 11, 2021, 11:50:04 PM
Ok so thought I'd post an update, our electrical contracting company has been working on a 7000 SQFT office building built in 1940 and since the electrical code requires abandoned cables to be removed, tons of old 25/50/75/100 pair had to be removed. Including some original 1940's phone cable.
Of course I threw a pile into my van for safe keeping..
This stuff with the brown outer jacket has solid colors no stripes.
It appears to be standard color code but no stripes.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Babybearjs on July 15, 2021, 01:03:07 PM
yeah seeing that makes one wonder how the original techs were able to keep things straight. with the new color code, coming across the older wiring can really be a head scratcher. kind of like European wiring. Great Britain and other countries used to have a DC color code, RED/BLK. then they finally updated it to BLU/BWN... still throws me as here in the US we use white for a neutral and all other colors are considered hot... they even usle Slate as a traveler wire in a 3 way application, which they call a 2 way switch. crazy!
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Key2871 on July 15, 2021, 02:23:08 PM
Are they paired by twists, or bundles?
Can't imagine straight through wires.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Jim Stettler on July 15, 2021, 08:00:53 PM
Are they paired by twists, or bundles?
Can't imagine straight through wires.
Twisted wire was used early on to help with RF type interference (possibly ground Hum as well), this is the 2-3 conductor baseboard type wiring. color thread or ridge to identify conductors,

 then straight through wire was used (think Quad). 25 pair was straight through

Once you hit CAT 3 wiring, then they started twisting for RF again.
CAT Rated 25 Pair has twist.
I think you get more twist per inch based on a higher CAT number.  Cat 5 has more twist  than CAT 3.
The number of twist per pair also changes. To maintain rating you need to keep the twist intact as close to the termination as possible.
This is for data speed and RF.
If you kink CAT 5 wire you can slow down the data.

------------------------------------------------------------------------------------------
To get back on the subject.
I think Cloth 26 pair was straight thru. the 26th pair was a spare pair.
Cloth colors were selected based on current dyes and the colorfastness of available colors ( per a bell lab report I read long ago)*

Jim

* it is fun to read some of the Bell Lab reports. Those guys were intense nerds doing a lot of pure research because they had funding to do so.
There are a lot of Bell Lab publications in the Internet archive.
https://archive.org/

Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Key2871 on July 15, 2021, 08:37:58 PM
 Jim, I am aware of why they twist wires.
I asked John because the picture he posted looked like straight through run, and yes for RF that's not great for the service, but more so for the installer finding proper pairs would also be difficult. When I first started working with cat 3 25 pair I had issues as some of the pairs weren't well twisted, but at least the color code helped me.
I can't imagine finding pairs in straight runs like that, yikes that could have taken much longer to verify the pairs.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on July 15, 2021, 08:54:58 PM

I asked John because the picture he posted looked like straight through run..

Greetings the pairs are slightly twisted, about as good as a cat 3 and its Stephen here not John  :)
I have salvaged 15 pair, 25 pair and 50 pair in the brown.
Its nice stuff, good condition very similar to the 6 pair that I would see with old interphones.
The interesting thing about the old 50 pair is there are no binder groups, it's extremely hard to tell  whats what in it.
You all inspired me to slice into the 50 pair more and upon very close inspection there is a slight white stripe on the 2nd binder group.
I was able to isolate all the groups.
More photos attached, they are hi-res so you can zoom in and see them close up.
(Ill probably run some of the 50 pair in my house for linking up old phones)
Also note the red-white spare pair as many large cables have them and bare ground wire, which I had not seen before.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Key2871 on July 15, 2021, 09:53:45 PM
Sorry Stephen, my bad.
But thanks for clearing that up. :)
Yea from the pictures I can't tell any real twists.
Is that still 22 gauge? Or heavier.

I've seen older station wire that was quite heavy, an when I tried using 3M splice beanies it was too large to use those.
I can imagine that would be quite difficult matching pairs if they aren't twisted well. I've run into some cat 3 50 pair that was the same way, very loose splices took more time to sort the pairs, some color markings were also poor that added to the time to make sure I had the correct pairs.
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on July 16, 2021, 12:43:59 AM
No worries I dont think I had ever properly introduced myself.  :D
I am pretty good at guessing 18 awg and larger from my many years as a sparky but 20 - 24 awg is all a blur.
Sometimes 8awg and 6awg still fool me.
I could break out the mic and measure it.
If any of you want some of this ill send it to you for the cost of shipping.
send me a PM.
After I cable every room in my house with 75-100 pair I think i'll be good for a while  ;D
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Jim Stettler on July 16, 2021, 01:17:09 AM

After I cable every room in my house with 75-100 pair I think i'll be good for a while  ;D
Over design always give a warm fuzzy feeling. it reminds me that , despite management, knowledgeable techs still rule.
Just pointing out the obvious,
Jim
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: Key2871 on July 16, 2021, 04:53:59 AM
75-100 pair? Woe that's serious cable.

As far as still getting 6 and 8 AWG confused that can be understanding.
I used to be a sparky, that was a while ago now.
But I knew a guy who had 50 pair riser cable, a spool full. I thought that was crazy, but he thought I could get a 25 out of it but realised it had no sheath separating the bundles.

I think that was a 1000 foot of cable that went to waste.
But what do you have planned with all that cable?
Putting in a serious 1A2 or more telephone system, or even larger EKS??
Title: Re: Mounting Cord wire Color coding for older keysets
Post by: 5415551212 on July 16, 2021, 02:12:41 PM
I would have never bought the cable but it was heading for the recycle bin on a large office remodel, and its in pretty good shape, sections of it were in conduit so its almost  brand new.
And I have got to do some other work in the attic this year, we live in a one floor house so I can drop a cable down the wall to each room. I think I have 3 cuts that will be long enough.
I do have some 1A2 and interphone type projects going on in my limited spare time, so it will be a neat way to hook up phones as I collect them.