What you should really have got if it is that your armour is blocking the signal is to get the spektrum carbon fuse receivers. http://www.spektrumrc.com/Products/Defa ... =SPMAR6255

They have extra long antenna's so that you can poke them outside the carbon fiber body on planes. You could then easily make up a small block of polycarb that mounts onto the backplate of the robot out the way of other robot's.

It does seem odd that your having issues though.