Separation of 2 meter and 70 cm Yagis

[arkansasbill]

I have a 13 element 2 meter yagi and a 15 element for 70 cm. I would like to mount them both vertically polarized with the 70 cm yagi on top. Do anyone have any idea what the minimum vertical spacing between the two yagis ought to be?
Thanks,
Bill KC5MN

 

[Moleculo]

I probably would go at least 3 feet apart from the elements. That would be about 1/2 wave away for the 2 meter antenna. It should be fine.

 

[74IN]

I admit that I'm weak on antenna theory, but I do see dual band VHF/UHF antennas on the same boom.

Couldn't they be mounted on the opposite sides of the mast at the same height?

 

[Moleculo]

I admit that I'm weak on antenna theory, but I do see dual band VHF/UHF antennas on the same boom.

Couldn't they be mounted on the opposite sides of the mast at the same height?

Actually you're right, they can be mounted on the same boom. I have an antenna like that and wasn't even thinking about it.

 

[Ronin]

A general rule of thumb (at least when mounting antennas horizontally) is to space them at least half the boom length of the higher frequency antenna.

I used a 10 element dual polarity at the top of the mast with an 11 element 432 yagi mounted about 4 feet under the 2 meter (4 ft between the 432 boom and the bottom of the vertical elements of the 2 meter) and it worked fine. I had no issues with interaction or disruption of one to the other on either band.

 

[TonyV225]

I was going to say I seen then mounted together aswell and wondered how it worked.