atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Cat 3 vs. Cat 5e for Voice

I started on Nortel Meridians back 10 years ago and was taught by a 25 year bellsouth vet the ropes. I'm young but I grew up around old school technologies that gave me the foundation for what I know today. Me I idolize old Bell Guys. Those were my heros..Call me a geek but they were.

The story on JKT (or so the story goes) meant "jacketed" vs. the cloth covered three lead "house" wire that had "thumb tacks" nailed through it to hold it to the base board. It was a three lead 19 ga. covered (jacketed) IW (inside wiring) that was stapled. The JKT is what I started with back in the day with Bell.

The different ga. bridle wire had two types. The larger had a ridge (ring) on one conductor and the smaller had a color (red) annealed under the rubber coating. The larger was used on open wire, the smaller on "drops" out of terminals.

Anyway, that was the local usage and material 40-some odd years ago at SWBT.

Interesting. So I wonder whether JK was just a shortening of JKT?

We've had quite a variety of color coding used here over the years. We never used the American red/green/black/yellow standard, but back in the GPO days the standard "quad" wire used for internal wiring was blue/orange/green/brown (blue & orange for tip & ring).

Flexible cords on the phones, however, were white/red/green/blue (white & red as tip & ring respectively, and generally bell return on the green which would be strapped to white on single-party line or to local ground for party-line service).

Internal cabling changed over to the standard white/blue, white/orange, white/green etc. pairs in the early 1980s.

Just to add to the confusion, drop wires installed for new services now use a completely different scheme again -- orange/white/green/black.

Both will support voice just fine. An argument could be made that C5e would be more immune to possible external interference (running too close to power, fluorescent lighting, etc), but generally both will suffice.

With C5e not costing much more than C3 for non-plenum applications I think a good business sense can be made for using C5e. In plenum applications there will be a bigger savings with using C3.

Of course, C5e does give you the added flexibility of using it for >10Mb for data transmission.

I, personally, would spec C5e. The cost difference is minimal and it is a more flexible install. But, that's just me.

I have never seen this. I just picked up two 400ft boxes of Aerial 6pr (Superior Essex) and they contain the standard color coding.

I know AT&T (in the midwest) uses the same aerial service wire I just purchased.

Who is using this new color code and do you know why?

Chad:

Paul is in the UK (as in England). That's why it's so different. It's being used by BT (British Telecom), the UK equivalent of Bell here in the US.

I do share in your question though. It seems that most of the world has accepted the standard US color code for network wiring being white/blue through white/brown. In the US, telephone has followed suit, even though telephone came first and actually invented this color code! It doesn't make sense that separate color codes are used for different cable types "across the pond".

I am sure that Paul will shed some light on this topic.

Take a look at where Paul is from - Norfolk, England. That would account for the different color coding.

Sorry for any confusion!

As to why BT adopted this new scheme with orange/white for the first/main pair on just the drops, I have no idea. It does seem odd, as it's a fairly new standard and W/B, W/O, W/G etc. were already firmly established.

The white/red for tip/ring on internal flexible cords here goes back many, many years. If I recall correctly, these were also the colors used on switchboard cords, with the addition of blue for sleeve.

There might be something about the origins of our old color coding schemes in Atkinson's "Telephony," a large two-volume set which was the "bible" of telephone systems 50 years ago. I'll see if I can find anything.

Maybe the Brits will do ANYTHING to avoid the appearance of being American. You all know how backwards we are.