As a test , put the rabbit ears type antenna out on the balcony. Run a long length of coax from the antenna out on the balcony to the tv in the apartment . The long length of coax can be connected to the rabbit ears type antenna with a in line coupler , commonly called a barrel because it looks like a barrel , an F81 coax coupler. Do Not use any type or kind of amplified antenna. The Tv transmissions are strong at you location even though you are on the other side away from the transmitters and the multipath (reflected signals) are strong also. An antenna amplifier or amplified antenna Will make the reception worse. An antenna amplifier of any type or kind will amplify the multipath and the Tv tuner will say , I can not deal with all that strong multipath and so there for you will not be watching some channels. If the reception is better with the rabbit ears type antenna out on the edge railing of the balcony , then I suggest a Winegard FVHD30 antenna , the >< shaped metal reception elements are what receive the Tv transmissions so those >< shaped elements are directed out away from the building. Here is a flat coax coupler that is used to get past windows and doors.
http://www.amazon.com/Flat-Female-Ty.../dp/b003ZECP24. Here are some places to buy antennas and etc. ,
http://www.winegarddirect.com ,
http://www.solidsignal.com ,
http://www.amazon.com