Can you put a multiplier reel on a spinning rod?

Yes, of course you can. In fact if you do you will not need a bite alarm at all. Put the reel on ratchet (and off lock) and the line will pull off the spool perfectly making all the noise you will need. If you are after extreme distance then a well set up multiplier teamed with a stiff rod and a practised pendulum cast will send a bait up and in capable hands over, 200 yds. In the margins, also, no problem, just swing the bait out under thumb control. Surprised that few carp anglers have really explored the potential of the multiplier.