I want to use an antenna for wired internet as an amplification for a 3G modem, is it possible?

Question

Computer networks

So, I need help in connecting to the Internet outside the city (15km from the nearest city). At the moment I am connected to the wired Internet at a speed of up to 8 Mbps (although in fact no more than 6, and most often around 4). At the same time, I pay a considerable amount for this Internet. Therefore, I became seriously interested in other possibilities for connecting to the network: in my case, this is a 3G modem.
For my current Internet, I had to buy an external directional antenna, which in turn is directed to another antenna (or a repeater, I'm not good at this) in my locality, and that in turn is directed towards the city to, probably, something else then. From my antenna comes an ethernet cable that is connected to a Wi-Fi router. And here we come to the main question: is it possible to use the current antenna as an amplifying antenna for a 3G modem, and if so, how, and what needs to be done for this?
I will add that at the moment the modem has a very weak signal (usually 1 stick).

Answer 1

Judging by the picture, you either have an antenna for Wi-Fi or a radio modem. It will not work with 3G - there are different frequency ranges. Look for a separate antenna for 3G. Here, for example, they are in quantity: antex-e.ru/store/34760

Answer 2

The short answer is no.
If only because you have to get a little drunk, and I suppose you don’t know how.
Another reason is a different range. WiFi equipment usually operates on 2.4 GHz or 5+. Your modem is unknown, but in the range of OPPS.
By the way, it is by no means a fact that you will have a channel better than 4Mbit through 3G.