sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring JK Cable Question

Going old school with this question.

I, vaguely, remember a topic about JK cable.

Part of the discussion, if my memory is correct, mentioned that the familiar green, red, black and yellow cable was used for Princess phones. Red/green for audio/signaling/dialing while the black/yellow was the power pair connected to the external transformer.

Was JK intended to be used to wire only a single telephone line, or, was it produced to be able to support two lines from the get-go?

Due to the lack of twisting, crosstalk would be an issue for long runs.

Bingo! I was looking in the Cabling forum as opposed to the 1A2.

Danka Professor!

my earliest recollection is that the yellow was used most of the time between protector and ts to provide independent ground for party line ringing and party identification for billing purposes. jk could not accommodate the wire needs for the five conductor early trimline or princess models.

Was the cable only three conductors? If it had four, what was the black used for?

The old original station wire was 20 gauge 3 wire, it replaced the 3 wire braded wire which was originally cloth cover, than rubber, no jacket.

I've seen the three wire braded cable. I think that I might have a few small sections stashed away in the basement. Based upon the discussions, it seems that JK wasn't intended to support two POTS lines despite having four conductors.

A while back, I had combined my church's two voice lines onto a single JK cable which ran about a total of 10 linear feet between the Verizon H-202 cabinet and the 66 block I had installed as a demarc.

After the church service ended today & the 4 or 5 people left the building, I pulled a hank of JK out of my stock and moved the second voice line over to it. I suppose such a short run between the cabinet and the 66 block wouldn't pose a crosstalk issue, but, I figured that I would separate the lines again.

Because the wires are not twisted pairs it was never intended to support two POTS lines. Problem is crosstalk. That's not to say that it was never used for two lines, you can get away with it but the longer the cable the better the possibility you can have crosstalk problems. (And don't ask me how long because I have no idea.) I remember that you will hear the ringing from one line while the other is in use.

-Hal

With all of the other POTS cables being CAT3, (and not experiencing any crosstalk), I figured that I might as well separate the two lines.

Now this brings up an interesting point. The daycare that leases space from us is has two POTS lines (1 voice & 1 fax) and two DSL feeds.

It seems that New England Telephone ran both phone lines from the telephone closet to the other side of the building via one JK and the other cable just has the voice line.

The distance between the phone closet (aka my office) and the daycare's areas is, roughly, 70' to 80'. I'm surprised that, after 30+ years, that nobody from the daycare hasn't complained about fax/data bleeding onto the voice line.

Then again, they had wall phone plugged in without a DSL filter for many years. A few months ago, I grabbed an unused filter and connected it to the phone for them on a day when they were closed.

How the heck did the DSL work? The ringer would have killed it.

-Hal