To build, use and configure your Jump Gate you need the following friendly codes:

BJG -   Build Jump Gate
AJG -   Attack Jump Gate
RJG -   Repair Jump Gate
Jnn -   Jump to Jump Gate ID# nn

This are ship codes and are case sensitive!
 

But beware:

"With the convienence of controlled hyperspace travel comes risk.
Each time a ship travels via Jump Gate, there is a small chance that an
alien ship will exit the destination Jump Gate with the traveller.  The
aliens are a warrior race, intent on conquering all that they see.
They will conquer the entire Echo Cluster unless stopped."
 

How to build a Jump Gate:

 If the ship's friendly code is set to BJG, an attempt to build a
Jump Gate will take place.  Jump Gates can only be built by Super Transport
Freighters, since one ship must have all of the building materials on board.

Minerals to build Jump Gate in ARENA 2:

  Neutronium: 800
  Tritanium: 150
  Duranium: 300
  Molybdenum: 900
  Supplies: 350

How to use a Jump Gate:

 Any ship that is at a Jump Gate and has its friendly code set to
Jnn, where nn is the ID number of the destination Jump Gate, will travel
to the destination Jump Gate.  It will arrive with its speed and destination
waypoint set to zero.  It will travel at no cost in fuel.  Builders of Jump
Gates will be informed when foreigners use their Jump Gates.  They will be
told what kind of ship came through the gate and who owned the ship.
Note: Ships with ZERO fuel can not travel via a Jump Gate.

How to attack a Jump Gate:

 Any ship that has beam weapons in excess of Tech 2 can attack a Jump
Gate by setting its friendly code to AJG.  Any ship that meets these
restrictions will attack a Jump Gate that is at the same location as the
ship.  Damage done to the Jump Gate is as follows:

 Number of Beams * Beam Explosive Power

For example:
A Nocturne destroyer with Heavy Phasers would do ( 4 * 45 ) 180 points of
damage while a Disruptor equipped Nocturne would do ( 4 * 20 ) 80 points
of damage. Damage doesnot effect the ability of the Jump Gate to operate,
unless, of course, it is destroyed.

How to repair a damaged Jump Gate:

 Jump Gates can be repaired by any ship carrying supplies and has its
friendly code set to RJG.  One point of damage is repaired for every five
supplies on board the ship.