In my laptop, the WIFI card was connected to the 2 antennas by IPEX MHF4 connections, which look like tiny coax connectors. Unfortunately the antenna connectors got broken, so I have removed them and soldered the antenna wires directly onto the WIFI card connectors (1/2 in the picture.)
It worked, but the WIFI signal strength now is much worse. I can rule out that the wires got mixed or cold solder joints.
Why that loss of signal strength? Is that because the impedance no longer matches (guess it is 50 Ohms?)?
If it is a problem with the impedance, could I buy a preconfigured cable with IPEX 4 connectors, cut the cable off after a few centimeters and solder it to the antenna cable? I would not like to replace the whole antenna because it requires me to disassemble sensitive parts of my laptop.
Is the length of the antenna cable relevant (must it have an exact length?)?
By the way, do the inner and outer pin of that connector carry the same signal, or is that shielded? The antenna cable is just 1 wire, so not shielded, but just to make sure - or is the outer ring connected to ground?