I have had an idea for some time: When you feed all these stacked antennas in
phase you will have optimum radiation to the horizon (or just above). My idea
is to add switchable delay lines to the higher located antennas. (You could
rather easily replace the damping networks in an attenuator with some coax do
make this.) Thereby you will be able to get optimum angle for "higher up"
propagation. You should select the steps to be small enough not to get "gaps".
Any taker? (K1TTT?)
Hans - N2JFS
-----Original Message-----
From: Tom_N2SR via TowerTalk <towertalk@contesting.com>
To: towertalk <towertalk@contesting.com>
Sent: Wed, Aug 10, 2016 9:49 am
Subject: Re: [TowerTalk] Stacking question - another reality data point
I used to operate at N3RS, who has 5/5/5 on 20, 5/5/5 on 15, and 5/5/5 on 10.
I forget the specific stacking heights/distances, but IIRC, they are 20:
37/77/117 feet, 15: 47/77/127 feet. 10: 25/50/87 feet. I am using 2 C31XR
tribanders at 40 and 80 feet, with separate feedlines. On 10, I have added a
5 element 10 at 25 feet, so while the distances are a compromise, I will have
3/3 @ 40/80 on 20, 4/4 @ 40/80 on 15, and 5/5/5 @ 25/40/80 feet. Which seems
very similar to Tim's and well as Sig's stacking distances and heights. I used
HFTA not for the gain numbers, but as someone else pointed out, to eliminate or
move the nulls for the arrival angles from Europe (mainly) and other
directions. As John also pointed out, I only have 1 tower, and the C31XR's
are just above the guy wires. So that's what I have, and I have no plans to
take the tower down to reconfigure the guy wires. I know some guys have
tribanders at 30/60/90 feet, but I chose not to do that. Tom, N2SR
From: "john@kk9a.com" <john@kk9a.com> To: towertalk@contesting.com
Sent: Wednesday, August 10, 2016 7:58 AM Subject: Re: [TowerTalk] Stacking
question - another reality data point These are logical stacking distances
and will definitely work well formost stations. Most of us do not have
dedicated towers for each band andwe have to adjust the spacing and heights to
clear guy wires and otherantennas. Fortunately spacing distance is not overly
critical. I usesimilar but slightly larger spacing and similar low antenna
heights toK3LR except on 40m.John KK9ATo: <k1ttt@arrl.net>,
<towertalk@contesting.com>Subject: Re: [TowerTalk] Stacking question -
another reality data pointFrom: "Tim Duffy" <k3lr@k3lr.com>Reply-to:
k3lr@k3lr.comDate: Tue, 9 Aug 2016 21:06:54 -0400I have 41 years experience
in stacking 2, 3 and 4 Yagi's high.After many hours behind the HFTA and NEC
model engines - then putting Yagi'sup in the air and using them for many years
here at K3L
R - these are thestacking distances that have worked very well at this Western
PA QTH:Lowest Yagi height:40 meters - 118 feet20 meters - 50 feet15 meters - 40
feet10 meters - 33 feetThen - stacking distances by band:40 meters - 72 feet20
meters - 60 feet15 meters - 40 feet10 meters - 33 feetAll OWA Yagi's on all
bands at K3LR have booms that are 48 feet long (itmakes a difference).73,Tim
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