Hi I have a Tp link AC750 MR200 Dual band with detachable antennas. I bought this for our caravan on the east coast of England. I researched the best SIM card for it and set it all up but the reception varies from zero to 1 bar. My question is can I remove the antennas and replace them with external ones fixed to the outside of our caravan to boost reception???? If so do both have to be replaced and which is the best to get????

thank you in advance 

Gary