[TowerTalk] 3-Stack Tribander Issues

[scottw3tx at verizon.net]

I recall a Dayton Antenna or Contest Lecture a few years ago where somebody (sri...forgot his callsign) from 3-land devised a feed system to multiplex on his tribander stack.  Worth looking at for the serious SO2R types.

73, Scott W3TX

-----Original Message-----
From: towertalk-bounces at contesting.com [mailto:towertalk-bounces at contesting.com] On Behalf Of GALE STEWARD
Sent: Wednesday, February 24, 2010 12:50 PM
To: Tower and HF antenna construction topics.
Subject: Re: [TowerTalk] 3-Stack Tribander Issues

K3WW has a 3-stack of Skyhawks and made something like 6.4 Meg last weekend in the ARRL CW DX contest. His locations is decent but not great so his system really works.

73, Stew K3ND




--- On Wed, 2/24/10, Jim CASSIDY <jc_ki7y at q.com> wrote:

> From: Jim CASSIDY <jc_ki7y at q.com>
> Subject: Re: [TowerTalk] 3-Stack Tribander Issues
> To: "Towertalk" <towertalk at contesting.com>
> Date: Wednesday, February 24, 2010, 10:03 AM
> 
> Hi Bill, The only thing I have heard about stacking
> tribanders was at W7GG. The had a 3 stack of KT34s and found
> that a 2 stack would work better for most bands.  I
> don't know any of the details, only that he did change to
> the 2 stack.  That was on a 195 ft tower.
> 73
> 
> Jim Cassidy
> 
> KI7Y
> 
> 
> 
> 
> > Date: Tue, 23 Feb 2010 22:30:46 -0800
> > From: wycpublic at gmail.com
> > To: towertalk at contesting.com
> > Subject: [TowerTalk] 3-Stack Tribander Issues
> > 
> > I’m thinking of building a 3-stack of
> tribanders.  Folks who are familiar
> > with stacked monobanders give me doubtful looks. 
> I’m wondering who on the
> > list has actual experience stacking tribanders, and
> what practical
> > observations they can offer.
> > 
> > 
> > 
> > By way of background, I was an EE in a past life, with
> a bit of professional
> > experience with phased arrays for VHF/UHF and
> shortwave broadcast, and
> > radar.  So I appreciate the phased array
> concept.
> > 
> > 
> > 
> > My contemplated stack has 8.6m spacing between
> antennas (with the top
> > antenna at 130’).  I recognize that half wave
> spacing has certain desirable
> > attributes, and that my spacing is a bit large for 15m
> and a bit short for
> > 20m.  But modeling suggests that’s not a big
> deal.  (I may cover 10m
> > separately.)
> > 
> > 
> > 
> > I expect to turn the top two antennas in tandem, and
> have the bottom antenna
> > independently rotatable.
> > 
> > 
> > 
> > I recognize that tribanders are, themselves,
> compromises.  However, current
> > designs seem a vast improvement over the designs of 30
> years ago.  (I’m
> > thinking of using one of the interlaced models, e.g.,
> with 2 or 3 full sized
> > elements per band.)
> > 
> > 
> > 
> > I’m not interested in longer boom yagis – narrow
> in azimuth and broad in
> > elevation pattern (e.g., beaming Europe only to put a
> null on Africa, or
> > beaming Japan only to put a null on
> NZ/Australia).  I’d rather have a
> > broader azimuthal pattern, and a selection of
> different elevation patterns –
> > depending on whether I drive antennas #1+#2+#3, or
> #1+#2, or # 2+#3, or
> > #1+#3, or #1, or # 2 or# 3.
> > 
> > 
> > 
> > What issues/observations can folks with experience
> relate?
> > 
> > 
> > 
> > Tnx/73,
> > 
> > 
> > 
> > Bill, K2PO/7
> > _______________________________________________
> > 
> > 
> > 
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> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>     
>         
>           
>   
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> 
> 
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