Otherwise a home-made sleeve aerial might be the only option.
what part of the circuit should this be attached to?
Those receivers are garbage
This may be correct, but the problem (from my perspective) is only the range. the receiver/transmitter pair does everything I want up to about 4-5 meters range. Trying to persuade it work for a couple of meters more is the big problem!
Is there an alternative on the market? I'm looking for a 4 channel key-fob (or anything very small) transmitter and an arduino compatible receiver.