PL259 on FSJ2 Heliax

Mounting PL259 Connectors on Andrew FSJ2 Heliax

We dont need no stinkin' N-connectors!

A good friend of mine passed me some Andrew FSJ2-50 Heliax to use on the station overhaul. FSJ2 is a super flexible heliax with a 1" bend radius specification, slightly lower loss than RG213 but as with all ham-retasked cable projects, expensive connectors. I was unsure about what to use it for but W7RY mentioned to me that it's easy to mount a UHF connector on it. The uses for this cable came info focus quickly. Thanks Jim!!!

But it was not that easy. No matter how I tried the FSJ2 would not slide into the Amphenol PL259! Eventually I figured out that in the connectors I have, there is a small collar internal to the connector that was preventing the copper shield from sliding into the connector. Mounting the connector in the vice and reaming the interior with a 3/8" bit proved to be the solution.

Here's the sequence that worked for me.

1. PL259 prep:

Ream out the PL259 to ensure it's properly sized using a 3/8" drill. Don't let the tip extend beyond the solder holes. Be sure to blow out the metal bits after the drilling work is done.

2. Cable prep:

A. Remove about 2" of the black outer insulation. Secure the cable using a vice with just enough pressure to hold the cable - being careful not to deform it.

B. Cut the copper shield at a point that will leave about 5/8" exposed copper. Once the shield is cut, unscrew the shield scrap to remove.

C. Cut and remove the white foam leaving about 1/8" of foam extending beyond the shield. The foam sticks to the center conductor so use plyers to spin the foam which will loosen the grip of the foam to the center conductor.

3. Assembly

Slide the connector shell onto the cable.

With the shell now on the cable, thread the PL259 onto the cable until it's finger tight (the point where the PL259 starts to bite into the black insulation). Use plyers and keep turning until the copper shield passes under the 4 solder holes. Here's what the connector looks like, ready to solder. Note the sheild is visible through the solder hole.

Solder the connector. I heat a single hole until the solder starts to flow and then touch up the other 3 holes. I'm not sure if there is a risk of overheating the junction but you want to avoid distorting the plastic insulator on the end of the PL259.