Have had *no* problems using a mish-mash of brands, our cars sport everything from KO, Futaba, Acoms, JR, Sanwa, Hitec etc etc and some other brands from Lord-knows-where that I can't even remember.

Just remember to plug everything in and CENTRE the servo on your intended radio before screwing it in and installing the horn. Sometimes when you put a servo onto a different RX the centering differs. Occasionally the direction differs too, so just flick the 'reverse' switch, no probs.