[TowerTalk] 3-Stack Tribander Issues

[Wayne Kline]

I installed the 3 Skyhawks @ K3WW. (These are the early feed method models).. He replaced three Hy-gain TH7's, and according to him there was a significant difference in performance improvement with the Skyhawks.

Both in performance and signal pattern over The Th7s.    The fact that the dual driven element design with bata tube feed  might have been hampered  by the 24" AB105 tower  .  Compared to the Cell design of the skyHawk

which exhibited marginal interaction to it's mounting configuration.     Mast/ring rotor/side mount 

 

YMMV

 

 Wayne W3EA
 
> From: tonno.vahk at mail.ee
> To: towertalk at contesting.com
> Date: Wed, 24 Feb 2010 23:13:17 +0200
> Subject: Re: [TowerTalk] 3-Stack Tribander Issues
> 
> I have 4 stack of JP 2000 tribanders on one of my towers. Those are interlaced 10 element beams (3/3/4 elements respectively on 20/15/10) with single feedline and boom of about 7.5 meters.
> 
> I find them pretty equivalent to respective monobanders with 3/3/4 elements and I find 9m stacking distance almost optimal on all bands (yes I have done extensive modeling).
> 
> The antennas are at 45/36/27/18m (150/120/90/60 feet).
> 
> I have been able to switch them in any configuration and in 99% of the time the full stack is as good or best. The cases with closer stations when lower 2 prevail are not important in contest. They hear me with the stack as well. So I have quit switching it.
> 
> The 4-stack BEATS HANDS DOWN my 5 over 5 on 20m (42/22m), 5 over 5 on 15 (29/15m) and 6 over 6 on 10 (26/19m). It simply perfect combination on all bands. It also beats the same JP 2000 3-stack on 35/26/17m.
> 
> 73
> Tonno
> ES5TV
> 
> 
> -----Original Message-----
> From: towertalk-bounces at contesting.com [mailto:towertalk-bounces at contesting.com] On Behalf Of GALE STEWARD
> Sent: Wednesday, February 24, 2010 10:39 PM
> To: Tower and HF antenna construction topics.
> Subject: Re: [TowerTalk] 3-Stack Tribander Issues
> 
> FYI..
> 
> K3WW has a stack of three Skyhawks at 30/60/90 ft and it works great.
> 
> 73, Stew...
> 
> 
> 
> 
> --- On Wed, 2/24/10, Bill Conwell <wycpublic at gmail.com> wrote:
> 
> > From: Bill Conwell <wycpublic at gmail.com>
> > Subject: [TowerTalk] 3-Stack Tribander Issues
> > To: towertalk at contesting.com
> > Date: Wednesday, February 24, 2010, 1:30 AM
> > 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
> > _______________________________________________
> > 
> > 
> > 
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> > 
> 
> 
> 
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> 
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