435mhz Transmitter and Reciever

I have a bunch of sensors that i want to use over RF. I have two way RF working well, but when i move the devices away from each other even a few feet they stop working. I have tried attaching wires for antennas. Is there special wire for antennas or do I need to do something special with the antennas?

Typically you want the antenna to be 1/4 wavelength. Google for 435MHz antenna to get some ideas.

433 MHz 1/4 wavelength => 17 cm straight solid wire, positioned vertical, both at transmitter and receiver end. This is the KIS (Keep It Simple) solution.

Un saludo,