How To Make a Transvestite SMA connector






This is an short description on how to make a Transvestite SMA connector for wireless LAN cards. You may have noticed that once you have rushed out and bought a 802.11b Wireless LAN card and then later wanted to put an external cable on it only to find that the SMA connector you bought from jaycar is different to the one on your WLAN card.

Never fear, all is not lost. I have not dealt with the SMA connectors that you can buy from jaycar as I have a large surplus of SMA connectors on semi-rigid coax that I have recovered from various sources over the years. Surplus semi-rigid coax is cheap and easy to get hold of if you know where to look, so I have used what was available at the time to make up the new style connector.

You will need to find an standard SMA inline female connector.

The connector should be easily removed with two small spanners. The threaded section with the teflon dielectric will then easily unscrew exposing the soldered base of the connect, the pin still soldered to the coax core.

It's the soldered pin that you are after, so carefully desolder it.


Now you will need a standard SMA Male connector. I used a piece of semi-rigid coax with an SMA male on each end, since they are very common.

First thing you will need to do is desolder the connector off the coax. A good soldering iron will make it easy. Mine is temperature adjustable so I give it lots of heat for a very short period and the connector just slides right off. The teflon dielectric may fall out, don't lose it as you will need it.

Desolder the Male SMA pin from the coax, you will not need it, so put it aside. Solder the SMA female pin back onto the coax in its place. Once you have done this you may care to take a piece of emery paper and sand back the solder dags on the piece of semi-rigid coax to make it easy to slide on and off. Check that the end of the pin will sit flush with the dielectric in the male connector and that it will not stick out past it. I screwed in the female section removed from the orignal female connector into the male connector carefully slid it onto the coax and soldered it in place.

I then removed the piece of the old female SMA connector and vola ! There you have it, a transvestite SMA connector.



Some finer points about semi-rigid coax. It is usally copper, but sometimes you will find it tinned or even enamald. When you recover it from old equipment it is usually bent into shape. Bending it more than twice will stress the coax with metal fatigue and it will break. Since it has already been bent once, (into shape) it is best to leave the coax in that shape until you want to use it. You may then carefully bend it straight etc without putting much more stress on it and causing problems.