The schematics should be pretty self-explanatory, even to someone without any experience with electronics. Needs specialized parts:
-98 NAR Regional manifest
suggests part may be present
-airplane wreck, now part of Horizon's Rest
The array's a government facility, so they had some pretty weird equipment specs. If you can't find the parts, we'll have to find out who made them and who knows if those facilities exist anymore. Cross your fingers.
Once assembled, the repeater module can be inserted into an array auxiliary slot, but you'll need to divert power to it through the array control system.