I am curious to make a better AM antenna using one of the monster
ferrite rods sold online. The main radio I plan on using this with has
no AM antenna jack however.

I have seen the little stick-on magnetic couplers sold with some of the
loop and coil antennas--and I am guessing that this is another littler
ferrite rod (which I have one, pulled from a junk radio) but don't know
and can't find anything online that suggests what windings to use.

As a general assumption, how many turns should the antenna rod have, and
how many should the coupler have? Considering that we don't know the
number of windings on the radio's actual AM rod, nor do we know what
level is ideal for the radio's tuner circuit....
?
~