Multi yagis

[jonbah]

I have two horz. yagis on the same mast. One HF and one 2 mtr.

How far away should the two meter yagi be from the HF Yagi ?

Jonbah

 

[freecell]

coupling can be minimized greatly if the two arrays are at least 3/4 wavelength away from each other at the lowest possible operating frequency of either of the two arrays. at this distance the capture area of the two meter yagi would be outside of the capture area of the hf yagi.

what's the low end operating frequency of the hf array and how many elements do each of the yagi arrays have?

if we place the capture area of the two meter yagi inside the capture area of the hf yagi we can move them a little closer.

http://www.ifwtech.co.uk/g3sek/stacking/stacking2.htm#Top

 

[jonbah]

Freecell-

The lower antenna is a Mosley Pro 67B 2 ele on 40 the upper antennas are 8 ele K1fo's spaced 84"
The Pro tuned in all bands except 10. 10 is tuning high starting at 28.8 - 2.1 to about 29.6 - 2.1 29.25 is about 1.2 The antenna should be tuning 10 about 28.4 to 28.8
Mosley wants me to drop the k1fo's to see if the problem goes away.? Allot of work for a guess.

 

[freecell]

how far apart from each other are they?

 

[jonbah]

The bottom K1fo is about 30" from the Pro.
The H-Plane stacking distance is 84' so it looks like the best I can do is move the lower stack at least 42" away from the Pro.
The tower and the K1fo's will be in the plane of the Pro but thats the best I can do without building another tower.

Freecell Thanks for your help.!
Jonbah

 

[jonbah]

Freecell
I worked on the antennas this weekend, I ended up taking down the second 2mtr yagi and moving the lower one 48" away from the Pro. I know I lost some gain on 2mtrs but the 10mtr swr problem with the Pro went away. I need to extend the mast before I can stack the 2mtr yagis again. I may just move them to my other tower and stack them E-plane on a insulated cross boom. Antennas can be alot of work.

Jonbah