SMB connector but 3.5mm diameter?

Question

I am trying to make a remote connection to the back of a Thuraya XT satellite phone.

The connector looks like an SMB female

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but an SMB plug doesn't fit. On a close inspection it turns out the ID of the socket is 3.5mm, whereas an SMB plug is 3.65mm.

Also, the centre contact does not have a hole in it. It is just a peg with a tiny spike sticking out of the middle. The reason is that the phone is designed to clip into a car holder, which contains a spring loaded mating part.

The centre contact is obviously just spring loaded together, but the outside (the shield) of the plug (in the car holder) is a sprung cylinder i.e. slitted so it mates properly with the solid cylinder of the socket.

I find it hard to believe these bits are custom made.

Would anybody have any pointers to the plug?

Obviously one solution is to buy the car holder and rip the plug out of it :)

mroberds · Accepted Answer

Given the price* of satellite phones, it wouldn't surprise me that much. There may be regulatory considerations, or perhaps the manufacturer is just trying to increase sales of accessories (which typically have a much higher margin).

(*I know the "real" price of a regular mobile phone is high, too, but it seems more common for satellite phones to be sold outright, rather than over time.)

I don't *know* if it's one of theirs, but Hirose makes several styles of weird and small coaxial connectors. A lot of them are for board-to- board use, inside a device, but there are some that are for external connections as well.

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For quantity one, that may be the fastest way.

Matt Roberds

Lasse Langwadt Christensen · Answer

Den fredag den 28. februar 2014 20.29.00 UTC+1 skrev  I believe there is some regulatory requirement to use a special connector so users can't add antennas that isn't approved apparently that's the reason for the reverse-SMA on most wifi stuff,  reverse-SMA just isn't that special anymore could it be reverse-SMB? -Lasse

John Larkin · Answer

FAKRA? --  John Larkin         Highland Technology, Inc jlarkin att highlandtechnology dott com

krw · Answer

That's the plan.  It just drives the market underground a little further. Most were R-TNC.  I haven't seen anything else lately but haven't looked hard.

krw · Answer

Usually but note that there are dozens of different keying options for Fakras.

SMB connector but 3.5mm diameter?

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