I have a wireless GSM module located inside a metallic enclosure. The module has an SMA connector to be connected to an antenna. I need a way to connect the external antenna to the module. The enclosure is to be used outdoor so the connector should be weather proof. That is protected from heavy rain, so IP65 is good.


ingress problem

I first saw this connector which probably do the job nicely: http://www.aliexpress.com/item/1pce-Adapter-SMA-female-to-jack-nut-panel-mount-O-ring-waterproof-connector-F-F/32619043048.html

Chinese SMA connector

There is an O-ring that should prevent water from entering the enclosure. Also I suppose that the white material inside the SMA connector (fluorcarbon) acts as an inner seal so water can't escape from there neither. So this connector is supposed to be weather-proof. I will then have to use an SMA to SMA cable to connect the connector to the module (inside the enclosure) and just connect the external antenna to the outside of the connector. The problem is that... this connector has no datasheet or drawing and its probably a very low quality product. I searched for something similar from molex or amphenol but with no luck.

I then came across this connector from molex:


SMA connector from molex

but it has no O-ring. So the question is, Can I apply some silicone between this connector and the metallic enclosure or an O-ring and consider this connector to be weather proof?

Similarly, there is something like this: http://www.digikey.com/product-detail/en/linx-technologies-inc/CSA-SMAM-216-SAFB/CSA-SMAM-216-SAFB-ND/1962867 SMA cable from Linx

Same question, Can I just use Silicone or an O-ring and consider the whole system rain-proof?

  • 2
    \$\begingroup\$ While applying silicone or using an o-ring around the body of the connector might prevent water from entering your enclosure, you also need to find a way to prevent water from entering the interface between the 2 connectors if you want your device to keep operating in the rain. It doesn't look like that aliexpress connector addresses this either. \$\endgroup\$
    – brhans
    Commented Jul 13, 2016 at 16:32
  • \$\begingroup\$ Check these out: gammaelectronics.net/cable-protection/rf-weatherproofing/… \$\endgroup\$
    – KJ7LNW
    Commented Nov 26, 2022 at 23:40

3 Answers 3


Short answer: maybe.

Long answer: If you'd like to KNOW whether this will work, you need to try it, building it reproducibly, and test it to see if it can uniformly meet your specs. Usually, it's more economically sound to buy the part that is rated for such use and follow the directions on how to use it correctly.

If a leak is not a disaster, you don't have to test as rigorously.


For a quick solution, I would suggest using silicone plus a cover over the whole thing so that rain can't get to it. That should last you a decent amount of time depending on the environmental conditions and the quality of the workmanship.

If you're looking for a more robust solution, start looking at suppliers like Huber+Suhner, Pasternack, or Amphenol. Expect to pay a lot for these, but they are very high quality.


The connector that you found is from the manufacturer GradConn. All datasheet and certified test data is available on their website.

I know that that IP protected SMA connectors are very limited available. I've seen a lot of solutions polyurethane potting from well known manufacturers to make an SMA connector watertight.

  • 1
    \$\begingroup\$ I tested the digikey parts to check if the connector is actually sealed from the inside and it looks well sealed. )I tried to blow air from into the connector by my mouth and check if air will go out! so I'm now sure that water/dust can't get into the enclosure. As for the portion of the connector that will be exposed to rain, the PTFE will probably prevent water from getting to the inner pin(which will be a problem if happens since water now connects the outer conductor with the central pin). I will test the enclosure to check if it actually works \$\endgroup\$
    – fhlb
    Commented Aug 29, 2016 at 14:18

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