[TowerTalk] Tribander Stacking

[Rudy Bakalov]

This is for a different type of tribanders- KT36XA. Upon consultation with M2 and HFTA, I came up with 105' and 68', for a stacking distance of 37'.  My terrain is completely flat and at about 1200' above sea level.

Rudy N2WQ

Sent using a tiny keyboard.  Please excuse brevity, typos, or inappropriate autocorrect.


> On Jul 17, 2016, at 12:50 PM, Filipe Lopes <ct1ilt at gmail.com> wrote:
> 
> Hello guys,
> 
> I have read quite a few posts here but I still am not sure about the
> distances I should use to stack my tribanders.
> 
> I am rebuilding my contest station CR6K in Portugal from scratch, meaning
> all antenas are gone, new antennas are being constructed and also a new
> self supporting cranck up tower 20m high is being built by my dad CT1CJJ.
> 
> For this new tower I want to make a stack of 3 x tribanders (10 15 20m) 11
> elements each. I tried a few simulations with MMANA and HFTA and what I
> found is that my stacking distances are best at 5.4m (+- 17 feet) from each
> antenna, meaning I would have the 3 antennas at 11.4 m / 16.8 m / 22.2 m (
> 37 / 55 / 73 feet). I then read one post from someone who says that HFTA
> has some sort of bug that considers maximums at < than 0.5 wl.
> 
> For info the top antenna will rotate when necessary and the other 2 will be
> fixed to USA and my QTH slopes down a lot towards USA. Also this is mainlly
> a USA tower because there is another tower dedicated to EU/ASIA.
> 
> So my questions are:
> 
>   - Is a stack of 2 tribanders @ 60/90 feet enough?
>   - If I consider the 3 tribanders the top one might be a lot towards EU
>   and so the other 2 towards USA
>   - Is 9 m (30 feet) the optimum stacking distance for tribanders?
>   - Will it hurt having for example 30 feet stacking between the 2 bottom
>   antennas and 17 feet between the second one and top one?
>   - I know the coax lines between the antennas and the power splitter need
>   to be electrically the same but does it matter how long they are, for
>   example 3x 25m is ok?
> 
> 
> All comments and suggestions are welcome.
> 
> Thank you so much.
> 
> 73's Filipe Lopes
> CT1ILT - CR6K
> F4VPX - TM3M
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