How to combine two coaxial cables?

Question

Antenna

I welcome everyone! In general, the question is as follows:
There are two coaxial cables coming from an external antenna, they need to be connected to a usb modem, which has only one antenna connector. Moreover, this is a type F connector, which I soldered according to the instructions from Habr

Answer 1

Because the modem obviously does not have the ability to use both antennas, just turn it on in turn and choose the cable where the signal will be better.
Of course, it will be most correct to connect the modem as close as possible to the antenna, and take a long USB cable and drag it where you need it.

Answer 2

The simplest solution is not to connect one of the cables.
Connect the cable that will give you the best signal.
What is your external antenna? You can try turning it to increase the signal level.