Marlborough Wi-Fi

Senao Antenna Hack

This article describes opening a Senao SL-2511CD+EXT2 wireless PCMCIA card and replacing the MMCX connector with a RP-SMA pigtail. I did this back in the day when MMCX pigtails were really expensive and hard to come by, and we needed a quick fix to get a high-power access point operating on the network.

I am not responsible for any injury or damage do while attempting anything listed in this article. You will also need to be confident at soldering, if not then I suggest you go and buy a professionally made pigtail lead instead. I also don’t recommend this mod if the card will receive constant movement, such as when wardriving.

What you will need:

• Senao card
• Pigtail of your choice
• Sharp knife
• Fine tip, temperature-controlled soldering iron
• Desoldering tool
• Tweezers
• Superglue or plastic cement

Ripping into it

Start by carefully running the knife along the seam of the plastic moulding at the end of the card. Be careful not to cut yourself or damage the delicate insides of the card. The best technique is to not push too hard and make several runs until the seal breaks.

Pry the top plastic shell up at the end, then pull it out from under the casing of the card as shown below.

The MMCX connector to replace on this type of card is the one facing you if you lay the card on a table so that the writing on top appears as you would read it.

Carefully desolder the connector. I found the easiest way was to heat all of the joints at once while gently lifting it off the PCB with tweezers. Applying too much heat will damage the PCB and surrounding components.

The photo below shows the connector removed.

Obtain a suitable pigtail and bare about 6mm of insulation from the end. Split the braid into two parts then twist each into a bunch. Fold them out perpendicular to the cable. Bare about 3mm of the inner conductor and tin all exposed wire. Be careful as the conductors are very fragile.

Tin the solder pads where the MMCX connector was mounted, then solder the pigtail in place as shown below. SOlder the braid to the two solder pads at the edge of the PCB and the centre to the middle solder pad below that. Do not let excess solder bridge the pads.

If all goes well you should end up with the finished result looking a bit like the one below.

The finished result. Although not shown here, I put some hot glue over the solder and cable to relieve strain on the joints.

All back together and almost looking professional. Use a few drops of super glue or plastic cement to glue the cover back on. All you need to do now is test it and you are done!

This entry was posted on Monday, November 24th, 2003 at 23:40 NZDT and is filed under Projects & Experiments. It has been viewed 1109 times. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.