There are a lot of ways of doing this. Does the little radio board have several outputs, is it working, what is it. Link to technical information please. We have the same problem with the amplifier, there are thousands available from a small ic to a megawatt system. Links to technical information on this will also help. And as Paul_KD7HB asked post your schematic with technical links to the parts as well. You might also research squelch circuits.