Tell us about yourself!
Yes and no. A simple RF amplifier would work. However if the RF power is more than 10mW you would need an amateur radio licence. I have such a licence so this is no problem for me. These transmitters are roughly 10mW so no, you cannot extend the range more than 100m. The longer the antenna does not mean the better the performance. The optimum antenna for this would be a 70cm long piece of wire. Any longer and you will reduce your range!! Simply put, the higher gain your antenna is, the further distance the transmitter will transmit!
I am thinking of building this. But can you enable a password for it?
can a passcode be added?