[TowerTalk] tri banders vs mono banders
Thu, 20 Jul 2000 09:40:13 -0500
Wow, free advice so remember the price when you compare the product. Hi
If it were me.
Leave the Tri-bander on top so it rotates and is usable over 3 bands. A
mono bander on top would limit the directions available to all bands.
Not a good outcome.
Space the monos at the appropriate spacing to put them at close to
optimal spacing of the tribander.
10/15/20 So if the tri-bander is at 95 feet.
If the 10 is a fairly small boom put it on the mast at 80 feet. It can
rotate with the tribander. Not bad. Now you gotta figure how to put it
in phase with the tribander. That's a discussion for another time. I
have to work today 8o)
put the 15 27-31 feet below .5 wl boom
Put the 20 40-47 feet below if its a .5 WL boom
Don't put them all on the mast.
Now if you plan right put the beams so they can rotate under the guys.
Put a side mount fixture on the tower (like mine, remember its fee
advice here) and go crazy.
Its worth the extra work to put dissimilar antennas in phase or close to
being in phase as you can. It can and is being done. This is another
Jim Idelson wrote:
> Hi Jay,
> I have a one-tower station. 80 feet Rohn 25 with 16 feet of mast above the
> tower. I currently have a tribander on the mast and 10, 15 and 20m monobanders
> fixed on Europe at various heights on the side of the tower. These are all fed
> separately - no phasing/stacking yet. Can you comment on the following ideas?
> Idea #1: Keep the antennas roughly as they are, but adjust the monobanders to
> the right stacking separations beneath the tribander. Add phasing/stacking
> Idea #2: Move all three monobanders up onto the mast with 8-foot separation and
> move the tribander down the tower to a side mount at a compromise stacking
> spacing. Add phasing/stacking switches.
> Idea #3: Do something else. Don't mix tribander and monobanders in a stacked
> 1. Remind us of the issues around stacking dissimilar Yagis.
> 2. What kind of stacking hardware configuration can you provide to handle the
> tribander [w/single-feed]/monobander mix?
> Although I could have directed this to you privately, I was thinking that your
> answers might be of interest to the many one-tower readers of this reflector .
> Jim K1IR
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