Advanced antenna basics

[roashru]

4 - 300 ohm antennas connected directly to coax = 75 ohms!

 

[roashru]

I hate the dugh questions. (4) 300 ohm antennas connected directly to 75 ohm coax. no transformer! (4:1) = 75 ohms. The (4) antennas must be connected at the same time for 4:1 ohms law.

 

[Tower Guy]

4 - 300 ohm antennas connected directly to coax = 75 ohms!

I love the title; "Advanced Antenna Basics". It's an oxymoron!

But 300 ohm is balanced, coax is unbalanced.....to make 75 ohm coax balanced, you can use a choke balun. A choke balun can be several turns of RG-6 on an air core, or ferrite beads can be placed over the jacket of the coax near the antenna end of the RG-6.

 

[roashru]

I love the title; "Advanced Antenna Basics". It's an oxymoron!

The cable length will do the work if long enough.

 

[Andrewwski]

Yes...don't rely on the fact that they now have the same impedence, there's still a difference between the balanced and unbalanced signal.

 

[roashru]

I hate making RF transformers (TX or RX). the core type and wire must be exact.