I am actually going to go ahead and confirm this. And it is actually really good to know, because I feel like the 3 con 1/8" jacks are much easier to find than the 3, even though I know URC uses the 4 con (with a dead RD (the tip)).

Here's what I have.

Elan HA-CB-308 (DB9 Female to RJ 45).

With a cat 5 terminated T568A, the pin out would be:

pin 2 = white blue
pin 3 = orange
pin 5 = blue

(if you prefer B)

pin 2 = white blue
pin 3 = green
pin 5 = blue

I have a URC standard 3.5mm"-3.5mm" stereo mini cable used for their RF antennas. It pins out as follows: (Top to bottom)

Tip: White
Ring 1 = Red
Sleeve = Black

So to my cat 5:

white to white blue
red to orange
black to blue.

Connect with Keyspan USA-19HS and have a functional pronto TS1000 replacement cable.

I'm sure everyone's been holding their breath since 1998. I certainly appreciate the help as my ring #1 stopped working on my pronto cable.