300 ohm to 50 Balun at antenna feedpoint, or near receiver?

Question

If I build a folded dipole, it will have an impedance close to 300 ohms. I have to match this impedance to the 50 ohms of my transceiver. I know many people match that impedance with varying lengths and combinations of ladder lines, 75 ohm coax, etc.

But let's assume I use a balun. I suppose the balun should be a 6 to 1 type, since it will be matching 300 to 50 ohms. Is this correct?

For most designs I've seen, the balun is placed at the antenna feedpoint, so there is only coax going from the receiver to the antenna, and this is most likely the way I'm going to implement it. What would happen if ladder line is used instead? If I use ladder line, could the balun be placed anywhere, and the rest be coax? I would assume there should be no problem as long as the antenna and feed line are 300 ohms, and the coax is 50 ohms, a 6:1 balun could be placed anywhere and it would not change performance. Probably even have less loss because of ladder line.

Answer 1

Yes, you need a 6:1 balun to feed a folded dipole. It might be a good idea to measure the real impedance of the antenna before making or buying a balun though. The real impedance can be anywhere between 200 and 300 Ohm depending on the exact shape of the antenna, the height of the mast, etc.

If you are going to feed an antenna using a coax cable you should place a balun at the feed point. If instead of a coax cable you are going to use a 300 Ohm ladder line a balun should be placed at the end of this ladder line. The balun can be connected to the transceiver directly or using a 50 Ohm coax cable of any length.