This page will have the antenna system details listed
This is an old magazine ad for the antenna that is currently being used on the N6OCS repeater.
The antenna is mounted at about the 100 foot level on the tower and is feed with Andrew LDF5 7/8 Heliax. It is currently set to 4 degrees of electrical down tilt. So far this seems to be about the best setting for a compromise between long range and in close stations that are under the shadow of the antenna. Mobile units seem to work this repeater best with no more than 3db gain antennas.