am antenna help

I have purchased a Russound ST2 dual tuner for medium wave (AM broadcast) and FM for my whole house audio system. I have hooked up a Radio Shack FM Stereo Antenna in the attic and it works well for FM. The AM antenna input is 300 ohm. Two loop antennas (about 5" diameter) are supplied but do not work well in the room I have the tuner as there is lots of noise and weak signal. I would like to mount the supplied loop antenna(s) in the attic. I am 18 miles from New York and only want to recieve local broadcasts (no DX). It is not practical for me to put up a 200 foot longwire. I have to make some decisions:

1. Can one antenna feed both tuners by being hooked up in parallell? Is there a signal loss?
2. Am I better off using 300 ohm flat TV type cable or should I use two

300/75 transformers (one at the reciever and one at the loop antenna) with RG-6 quad shield? I am wondering if the transformer loss is worth the possible noise reduction from the coax.

1. Should I be able to use 1 loop for the two tuners and the coax, is it best to split the 75 ohm coax and use independent 300 ohm transformers or to split the 300 ohm feed from one tuner to the other?
2. Is it possible to use the FM antenna for the AM and how would it be best to split that up? (I would have to feed two FM and two AM tuners but only two could be used at once).

Thanks, Eric