I use line instead of the cable. I removed it so it would be "softer" for my crew when i tack (didnt really make any difference).

I use vectran but i have friends that use regular non stretch 3/16th. I have a friend that has omitted the cable/line completely without problem. His jib blocks simpy sit a few inches above the tramp when under tension.

You can see that i have tied off the tan vectran on the starbard side of my picture