Joining 2 Bluetooth/Wifi Antenna Cables together

From your description it sounds like you have two systems with the same issue is that correct? Or are you trying the splice them together (which you shouldn't do as you then defeat the design of the COAX cable to protect the radio signal to the point it needs to be exposed at the antenna or in the reverse entering into the receiver.

The antenna wires are what we call COAX of two conductors the outer braided ground which surrounds the inner wire held within the dielectric which we call the core wire. The two must not touch and need to be held at a set distance from each other to be effective. This is where the thickness of the dielectric comes in but we don't need to worry about that here, as we aren't replacing the cable or trying to solder it on top of the mate connection or try to splice it back together.

So do you still have the connector piece? And is the fold over crimp tabs still present on them? If not you can buy replacements. Thats the first step.

The next is the cables length still workable and the braid still in good shape there is very little slack, so if the cable is cut or needs to be trimmed you made have issues.

The first vid (Louis Rossmann) is often what one needs to do to recover the connector and feeding the cable end back in. The other way is getting a fresh cable tail which has the connector already mounted and tested. Feeding the old one out and then feeding the new one is replacing the old one. If the connector is shot or the cable is too short I find this is the quicker way and the a package of a dozen is not that expensive. As time is money consider that as well.

Make sure you plug in the correct antenna into the correct port as the antennas are different!