Hi Ranko
Your idea is very similar like 9A1TT project I planed already few years a go
Rich will use 2 x 70m high towers with plus minus 50m spacing (I don't remember
exactly, but I still have somewhere eznec files)
On each tower 2/2 for 80 , 4/4/4 on 40m and 6/6/6/6 on 20m
Stacking distance of towers for 20m is to big but still gains a bit
On other two 42m high tower will be 15/10 stacks
Both towers will be ok to use it board side or end fire
I played with justins G0KSC idea adding some parasitic elements in between to
optimized the stacks (you can change diagrams for a lot)
I think you can see his presentation somewhere in archives of Contest
university in Monte chiari ...it was 2017
Using tribanders and 40m you will need to decide if you want to optimized 40 or
20m
I think distance for 40m will be to close if you optimize this for 20/15
For triband design ....there are many ...
You need good aluminum on that location and I will go for shorter boom
......you know your enemy much better than I on that windy place!
I will go for UA2FZ or maybe EA antennas material (Rodirgo told me he have
different quality of aluminum he could use)
73s and good luck !
Braco
--
Emir Memic
EMS SOLUTIONS
Köhlergasse 12/3
1180 Wien
+4369919227041
emir.memic@emssolutions.at
-----Ursprüngliche Nachricht-----
Von: CQ-Contest <cq-contest-bounces@contesting.com> Im Auftrag von Ranko Boca
Gesendet: Freitag, 20. April 2018 16:10
An: donovanf@starpower.net
Cc: cq-contest <cq-contest@contesting.com>
Betreff: Re: [CQ-Contest] 4O3A Station rebuild
Hi Frank,
nice to hear from you.
I will have 3 rotary towers. On 40M I will have 2/2, plus four tribanders.
Towers are in triangle, and will be able to turn two of them toward USA or JA.
Want to have optimized 4x 2L40 in H frame configuration.
Exactly what you are saying, I have to look for 20M antennas, to fit this
optimized 40M distance of towers. Based on its boom length, I will look for
adequate tribanders, or will decide to make it by my own.
I hope it is more clear now?
73
Ranko
On Fri, Apr 20, 2018 at 4:00 PM, <donovanf@starpower.net> wrote:
> Hi Ranko,
>
> You didn't mention WHAT You want optimize...
> Maybe you want to optimize gain in a 4 Yagi stack?
>
> It's not possible to optimize gain on both 40 and 20 meters.
> My recommendation is to optimize gain on 40 meters and Use long boom
> tribanders to optimize gain on 20 meter And not try to use two towers
> for horizontal stacks.
>
> EZNEC can easily determine optimum spacing
>
> Good luck with your rebuild!
>
> 73
> Frank
> W3LPL
>
>
>
>
> ----- Original Message -----
> From: Ranko Boca <4o3a@t-com.me>
> Cc: Contest Reflector <cq-contest@contesting.com>
> Sent: Fri, 20 Apr 2018 04:04:04 -0400 (EDT)
> Subject: [CQ-Contest] 4O3A Station rebuild
>
> When making something big, such as a life time contest project, it is
> better to share and listen for advice. Here we have an experienced
> group of contesters and maybe someone has something to say that I am
> not considering at the moment?
>
> I am intending to rebuild the 4O3A station. One of the tasks is to put
> two towers in stack toward USA.
> On each tower I will have a stack of 2L40, together with a tribander stack.
> The idea is to optimize horizontal distance of towers on 40M and 20M.
> Other bands can't be optimized, and are not that important.
>
> I am still looking for tribanders designs, either to buy them or to
> build them.
>
> Any advice is welcome.
>
> 73
> Ranko
> _______________________________________________
> CQ-Contest mailing list
> CQ-Contest@contesting.com
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>
>
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