Combining two Antennas - Balun Polarity

[davidkjohnson]

When combining the two antennas do you reverse the leads on one at the balun on the antenna so they are in series or do you keep them the same. Does this matter if they are pointing in the same direction or offset by 90 degrees?
I think I am going to reverse the leads on one and see what happens.

[GroundUrMast]

Are the two antennas identical?

What make/model are they?

What type of combiner are you proposing to use (make/model)?

[davidkjohnson]

Thank you for responding.

I currently have two identical generic yagis; they are vertically stacked approximately 1 meter apart. I may replace them with name brands if I can prove they will improve a reasonably good reception. I am using an RCA splitter reversed to combine them. They are grounded from the shell of the splitter. I have identical lengths of RG6 from the antennas to the splitter/combiner. I have them aimed 90 degrees from each other to pick-up stations in two large sources. I run RG6 from the combiner to the television. On an average day I will get all the LOS channels plus some unlisted channels. Occasionally I lose some of the more distant channels and would like to reduce those occasions. I am also considering two more yagis to point opposite to the existing ones to cover some fringe are locations.

I am interested in your thoughts.
cheers

[GroundUrMast]

To answer your question re. balun polarity, the signals need to combine in-phase. Reversing one balun will result in less gain.

If you look at commercial antennas, you'll notice that they usually use open wire connections between elements that are ganged together. This is efficient (less loss). However, the diameter of the wire and space between wires determines the characteristic impedance of the transmission line formed. The 'phasing lines' must be the correct impedance to be able to act as RF transformers. If you get it wrong, the RF will not be coupled efficiently.

Some folks find that antenna location makes more difference than 2 or 3 dB of antenna gain.