Mechanically weak pin connection for antenna on PCB - can I solder it on?

Hi Guys,

I bought this modem and it is all working fine, however I have a concern regarding the antenna wire it comes with. It is very weak in terms of physical connection to the slot for it on the PCB, therefore it keeps falling out with the slightest tug even when I hear a click sound when it is connected - meaning it is as secured as possible.

Can I solder it on to keep it absolutely secure? Of course taking into account I cannot bridge between any other circuit contacts on the PCB in the process.

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Hi Samuil
Not a good idea.
Just how and where were you planning on soldering.
How often has this connector been connected and disconnected. These things have a very finite life and I think you may find these “click in” types have not too many guaranteed mating cycles. That is, they could be a bit fragile. SMA or other screw up types are much better but of course progressively more expensive.
I think this connector type is designed to be connected once and only disturbed on the rare occasion when something major is undertaken.
You must also take great care when disconnecting and reconnecting to make sure the connector is withdrawn and reinserted while EXACTLY vertical or damage WILL occur. I think there is a tool for this purpose. This problem has come up in a previous post.
Cheers Bob
PS: As an example. I have a similar connector, but very much smaller, connecting the WiFi/Bluetooth unit to the main board on my Mac Mini computer. I have VERY CAREFULLY disconnected this once when I replaced the hard drive with a SSD. I reasonably expect this is the one and only time this will happen during the life of the computer (late 2014 model).

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Hi Robert,

Thank you so much for your response and completely understand. My intention is to keep it on permanently which I guess is a good thing.

After speaking to Waveshare apparently the connector is a IPEX4 connector, I am looking to purchase a replacement and stumbled upon the following link.

Would you happen to know if this is the correct replacement for the aforementioned modem? I cannot see if it is IPEX4 and I know large pins that connected onto the MAIN header on the 4G PCB’s come larger i.e. for the 7600G which I also have (and won’t fit my 7600H).

Also if you manage to recall the tool for this I would buy one in a heartbeat, I had a look on Google and nothing is really coming up apart from IPEX MHF-4 push/pull tool which I don’t believe is the appropriate one.

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Hi Samuil

That is the one. There is apparently a U.FL connector which is similar but a different tool. there is a pix of both on this web site Insertion Tools for U.FL & MHF4: Push/Pull Connector to/from Jack. You will have to ascertain exactly what this connector is. I am not familiar with this unit and just don’t know
Best of luck getting this information from Waveshare or RPi. Someone at Core might know exactly what connector this is. The blurb just says “antenna connector” Lovely, I could think of dozens of different co=ax connectors and they are nearly all used to connect antennas.
Cheers Bob
Just have a quick look. It appears RS Components UK have one of them at least. If you can establish exactly what connector this is you will probably find the tool at RS Components or Element 14 locally.
Cheers Bob
PS: I was a bit quick off the mark there. It seems that you have already established from Waveshare the connector type as IPEX4 which I assume is IPEX MHF4. You would do well to be certain before rushing out and purchasing tools.

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If you are not going to detach it, you could epoxy glue it with something like Araldite. No problems with accidental shorts. I’d drill a hole either side, loop a bit of cotton or similar non conductive thread several times over and under then epoxy the lot. Epoxy by itself may not stick to the PCB.

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Alan
You’re kidding right???
If you are going to do something like that please use hot melt glue or something you have a chance of getting off. Araldite will stick to the board but if you ever have to remove the connector that may be the end of the board.
You should not drill holes in any board or even open out mounting holes unless you are sure the board is only single layer. If you try this on a multilayer board there is a very real chance of damaging internal tracks rendering the board pretty useless.
Do the job properly or be prepared to scrap the unit later.
Cheers Bob

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Those connectors looks like IPEX (Version 1). Difference between the connectors (IPEX = MHF) are here.

Looking at the dimensions, IPEX might fit from connection depthwise, but not from the rectangular dimensions perspective.

This link has their MHF4 to SMA connector. Apparently, they ship worldwide, probably will cost an arm and a leg to get to you.

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Happened for real to a video card a friend tried to modify.
He just cut off a tab with a pair of side cutters, it was in the way of putting it into a PC.
The Board never worked again.

Under a 10x Magnifying glass you could see at least 4 layers damaged.
Treat board with respect as @Robert93820 has stated or be prepared to bin it for ever.
Regards
Jim

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Thank you all so very much for your help.

I will try mechanically restrain the end of the IPEX side of the cable to avoid any extreme measures, however will resort to hot glue method if this is not feasible in my systems current form factor.

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Found a link of ebay Australia. Ipex4 to SMA pigtail

If IPEX connector does not fit (can remove hot glue with little soaking with rubbing alcohol), the above link might help.

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Yes you are right, care is needed. I did look at the board in the photo, thought about what might get damaged by drilling a small hole. I’d be guessing but I’m thinking it is a two layer board, and at an edge there would be a conductor going to the center pin of the connector, and ground plane on the other side. An inspection would verify this. I haven’t seen the back, but the thoughts are based on other boards I’ve seen. Those thoughts didn’t make it into what I wrote, which was a bad omission. These notes are read by people that haven’t spent decades repairing stuff, so for them it isn’t the right solution.
I did say “if you are not going to detach it” when going down the epoxy route. It is a final solution, you don’t get a second chance. Hot glue would be fine.

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Hi Alan

You are probably correct but you need to be sure. I would think more than 2 layers would be a bit expensive to retail this sort of thing for the asking price.

About the most layers I have seen is 12. It was a very complex back plane for 96 way connectors. 2 such connectors for each board slot.
Cheers Bob

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