I understand why balanced line has much less loss that coax. However, I have wondered why 450 ohm balanced line seems to be preferred some much over simple (cheaper and easily available everywhere) 300 ohm TV "twin lead". Since most tuners have a 4:1 balun for balanced feed line, I would think the 300ohm would be a closer impedance. My login would say that the tuner output is looking at a situation where the 4:1 balun is operating at 50 X 4 = 200 ohms. Attaching to a 300 ohm feed line would be 100 ohms difference. Attaching to a 450 ohnm feedline would be 250 ohms difference. I could understand a possible advantage if at the antenna input there is a very high impedance, then the 450 would be closer than the 300. Is there an error in my logic, or something I am not taking into consideration, besides the fact that usually TV Twin lead is pretty small wire gauge and may not handle higher wattage well?