Securing uFL Connector for External Antenna on Photon

I am planning on using a small external antenna that has a microcoaxial cable and connector that can snap onto the uFL connector on the Photon. However, this connection does not seem to be rock solid, and in my application there may be some vibrations. I am concerned about this connection working itself loose over time and am wondering if anyone has a suggestion for making the uFL connection more secure/permanent? Best idea so far is a dab of silicone adhesive, which may work out just fine, but any other thoughts?

Hello @sddw

I would recommend not to use your typical silicone adhesive. The reason being it might create corrosion on the connector.

The adhesive I would recommend is the LocTite 5145 electronic sealant. I have used it in the past and it is very strong. You don’t need too much of it, a small dab is enough. If you apply too much of it, you run the risk of affecting the RF performance.

http://www.digikey.com/product-detail/en/230079/1000-120-ND/2499380

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Great, thanks @peterqu! Our PCB assembly house said they typically use DOW 732-C silicone sealant when an adhesive is required on a board. But they have no experience using it on a uFL connector. I will look further into the LocTite 5145 as you suggest.

I’m assuming it would be ideal to simply plug in the uFL connector (without yet adding any adhesive), then put a small dab covering the whole connection?

Yes - connect first, then seal.

I would also suggest using a tie-wrap or similar to act as strain relief on the coax, so that you minimize the opportunity for movement at the u.FL connector. That way all the adhesive has to do is stop the connector from vibrating loose. You may need holed on your board or whatever to use with the tie-wrap, but if you’re concerned about vibration it will help.

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Great idea for the strain relief, thanks @AndyW. That plus the adhesive and I’ll sleep easy over that connection :slight_smile: