Installing Standard Type N's on LMR-400, J. G. Liebmann (K5JL)

Installing coax connectors is usually one of those things that you would rather not have to tackle, but often an annoying necessity after installing coax. To compound the matter, the large center conductor on LMR-400 or 9913/14 coax does not fit the most common (standard) Type N connector. In this article, Jay addresses this matter colorfully.


Standard Type N Connectors may be installed on LMR-400, 9913, and 9914 coax without need to solder the center pin. The process is simple and fast.

The only tools needed are a 4-40 Tap and Die. The center pin is tapped and the center conductor of the coax threaded.

Items needed: Standard Type N Connector, Coax, and 4-40 Tap and Die

Cut jacket to expose about 1/4" of the center conductor.
Install washers and locking nut in proper order.
Dress the outer shield around the contact washer.

Using 4-40 die, thread the center conductor of the coax.

Center conductor threaded with washers and lock nut ready to install.

Tap the center pin using the 4-40 tap.

The center pin with the tap inserted

Remove the tap and screw the center pin onto the center conductor of the coax. Soldering is not necessary, however, if you wish, you may solder the center pin to the center conductor at this time. Assemble the N connector and your project is finished.

Go to the top