M103c swr across 11 meters

[wavrider]

18 to 20db difference in polarization. If the super cb'r is vertical and you are horizontal what would be up to 3 S' units (assuming your receive meter is 6db per S unit) add the rejection of the yagi and there it is, next to nothing on your receive.

Glad the yagi worked for you.

Just fyi, if you have a true cb'er close to you, go horizontal! I have one, tunes up his 2kw amp..... every twenty minutes! I could cut him down to 1 by turning the back corner to him. Eliminating his bleeding me. I can't do near as good vertically, but I can knock him down enough to hear my friends to the north with no issues.

 

[Shockwave]

Ever wonder why all manufacturers of gamma matched vertical yagi's always suggest you mount the gamma facing down? I know it's hard to fight the common sense logic that "it would have to work better pointing up" but it doesn't. Any driven element that is fed with a single gamma match will develop a slightly skewed pattern that will favor the side the gamma is mounted on. This is true of both vertical and horizontal antennas.

We are only talking about a few degrees difference here and the more director elements you place out in front, the more it covers up this slight offset. Still, many operators have taken the time to notice their horizontal yagi pulls in a stronger signal when they turn their antenna a few degrees past the true bearing in the direction the gamma is NOT. Because the signal is stronger off the gamma side.

Translate this into a vertical beam and you have a choice. Point the gamma down so that more signal is lower on the horizon where it's needed or point the gamma up and steer more of your signal upwards rather than having a stronger low angle. Lower angles also permit longer DX contacts.

The differences here are small and usually only noticeable at extreme distances where the signal would be weak or perhaps non existent with the gamma pointing up. The point is while you may be able to gain a little signal in the distance, it may not be worth the effort or the work of trying to obtain the same match and bandwidth that you seem currently happy with.

Since you have the 3 element it will always be much more difficult to obtain a good vertical SWR. Even if you get it perfect, the slightest change can throw it off. Just turning the beam and having the coax move closer or further from the driven element an inch or two can cause significant change in SWR.

I have a suggestion for you. If it were my installation I'd put the 3 element on a 45 degree angle (gamma pointing down) between horizontal and vertical assuming vertical is important to you. In most cases you would only drop 1/2 S-unit to people on the vertical side and have the benefit of being able to talk good DX favoring the horizontal side.

However, since you have a 3 element with the driven element so close to the mast, noticeable power is being coupled to the mast when positioned vertically. When you move this antenna from vertical to a 45 degree angle you have the small signal lost in the vertical mode countered by the small signal increase by not coupling energy into the supporting mast.