Radar cable not budging in mast

[Windhunter]

Trying to replace my non-working radar scanner with a slightly newer model. Requires 12 more inches of cable inside the radome. It has plenty of extra cable under the sink at base of mast post . Radar is on a pedestal halfway up the roller mast. I went up the mast and tried pulling more cable out of the mast at the pedestal while crew was pushing it in the hole to mast post under the sink. Wouldn’t budge. Couldn’t get any additional cable up the mast. They couldn’t feel me pulling and I couldn’t feel them pushing. It’s as if it’s fastened somewhere inside the mast but not obvious as how or where. Anyone know how and where it would be fastened?