First, do no harm

PS: The Preventive Maintenance Monthly, Dec, 2004

The AS-3900A antenna, NSN 5985-01-308-8988, used with the SINCGARS ground radio is getting damaged far too often.

The damage is happening when it's assembled, when it's installed, and when it's removed. The damage is happening to both the lower and upper antenna elements and the antenna spring base.

The antenna is not getting a break! Or at least not a good one.

Most of the damage is to the threads on the elements and the base and it's happening because proper assembly, installation and removal procedures are not being followed.

DO:

* Line up the upper and lower elements and gently push the elements together until the assemblies fit snugly.

* Rotate the upper element clockwise onto the lower element until the two elements are firmly attached.

* Carefully rotate the upper element counter-clockwise to disconnect the upper element from the lower element and carefully separate the elements.

DON'T:

* Overtighten the elements! Over-tightening the elements will increase the likelihood of damage to interior components--like the contact point--of the upper and lower elements.

DO:

* Carefully line up the ferrule on the lower antenna element assembly with the threaded base on the antenna spring base.

* Slowly hand-tighten the ferrule by wrapping your hand around the metal ferrule and rotating the ferrule clockwise until the antenna is firmly attached to the spring base.

* Reverse the procedure to disconnect the lower antenna element from the spring base.

DON'T:

* Install the upper and lower element assembly onto the antenna spring base by rotating the element to secure the ferrule onto the spring base. This kind of mating might damage the lower element assembly with the separation of the fiberglass antenna element from the ferrule. Also, you could do damage to interior components of the antenna elements resulting in degraded antenna performance and to the thread surfaces.