I know the logic i.e. keep metal things (feeder / masts) out of the way of the antenna / elements. In the real world however things can and are often different.

I have a 19 element 70cm Tonna and a 9 element 2m Tonna. They are mounted on a horizontal GRP pole, effectively side by side. The feeder currently runs from the driven element along the boom to the GRP pole where it makes a radiused turn onto the GRP pole, effectivley being in line with the elements before heading downwards at the central mast (see pictures).

I know that ideally the feeder should not cross between the elements and should in my case go vertically, but the question is how much is this going to eaffect the antennas performance? I do have the option of re routing the feeder so it does not travel inbetween the elements such as I hope is shown by my sustandard photshop editing - drop feeder below boom, say 20cm then track back to the GRP pole beyond the elements. Is it worth it? To read more on the subject can you recommend a book / site

Thanks Andy

I'd avoid running it the way you have it.
Without an overview it's difficult to suggest anything.
Can you post an overview?

Cheers

Tony

Overview, hope this shows the layout.

Could you drop the coax from each mast to boom clamp to a point below the rotator cage, leaving enough slack to allow for rotation?
This would get it out of the plane of the elements and minimise pattern distortion.

Thanks for the responses, I have for now looped the feeder downwards from the middle of the boom then attached it to the central mast. It may cause a problem with wear as the feeder swings in the wind, but only time will tell.

Can anyone recommend reading material to help show how the antenna pattern is affected by poor feeder routing?