I had an unused folded dipole with a 75 ohm connector I tried for the hell of it and it works amazing.
Edit: This one pretty much - http://www.amazon.com/FM-Dipole-Antenna-Male-connector/dp/B00EIB70N2/ref=pd_bxgy_23_text_y
Note that the Y526 is 7 feet long and 9 feet wide. VHF-low antennas are big. Normally they have to go outside.
Smaller antennas will just work worse. You can't beat the physics. If the bunny ears almost worked then it is very possible that a home made single element in the attic could work as the optimal width for the bunny ears put flat is 74.5" (ch 6):
http://www.hdtvprimer.com/ANTENNAS/RabbitEars.html
Chances are your bunny ears were not that large.
Channel 6 is fairly close to the FM band. Instead of making something you could try a FM twin lead antenna in the attic. Example:
http://www.amazon.com/FM-Dipole-Antenna-Male-connector/dp/B00EIB70N2/
You would need a UVSJ and a short 75 ohm cable to get things connected to the existing system.
Edit: found an example of an FM antenna with built in matching transformer.
Edit2: it says that the FM antenna I used as an example is a scam and has no matching transformer. So do something like this instead:
http://www.amazon.com/Axis-PET-10-8110-Dipole-Antenna/dp/B000EIOQBM/
http://www.amazon.com/Parts-Express-Push-On-quot-Balun/dp/B0002ZPIOQ/