How to change this u.Fl connector to SMA?

Development Hardware
1

I got two SX1262 T-Beams with u.Fl connector on the board. I have a cable attached to it which has an SMA female jack on the other end. I believe these cables are crap and do not transmit the signal properly.

Also, I do not find this kind of connector reliable. I would like to switch it to something present on my older SX1278 board with the integrated SMA connector.

Any ideas on how I can do this?

lily
lily800×573 103 KB

2

You should be able to desolder the ufl and solder a sma connecter on to it. With the terrible range you’re getting you might have damaged radio modules though too

3

Is there any tutorial for this?

Also, how would I have damaged the radio modules?

4

I think they can be damaged if there is no antenna attached while they are powered on.

5

I never did this. I am always careful about this.

6

If you suspect that your UFL-SMA cable is faulty, you can check it with an ohm tester.
It is either interrupted, shorted or it is OK.
Center pin - center pin should be zero ohms and outer shield to outer shield should be zero ohms.
The center pin to the outer shield should be infinite ohms.
Of course, there may be an intermittent short circuit or interruption.
If the UFL-SMA piggytail is faulty it can have the same result as no antenna at all and thus may have damaged the LoRa module

UFL connectors are not very sturdy and can only be pressed on a limited number of times. The SMA is much sturdier and can be screwed on many times.

7

@costo

I wonder why LilyGo decided to include these crappy pigtail connectors. If my Lora Module is damaged, why am I still able to get messages across?

@joshpirihi Do you know what’s under the u.Fl connector once I unsolder it? What do I solder the SMA connector to, exactly?

8

In my experience with rf tranceivers it will mostly be the tx-power output that may have damaged itself. If so the output-power can be up to 10-30 dB less than a healthy module will output.
Receiver side is less sensitive for damage.

So it is still possible to communicate on a short(er) range with a damaged module,

If you remove the UFL part, a SMA part can only be placed in one way.

9

I didn’t understand this part.

10

That UFL connector is just a surface mount part, when you remove it it’s just solder pads underneath. There are holes for the SMA connector already, the board design supports both types of connector, it just depends what they use when building it at the factory