[TowerTalk] Fwd: Stacking question - another reality data point

[Hans Hammarquist]

 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 at contesting.com>
To: towertalk <towertalk at 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 at kk9a.com" <john at kk9a.com> To: towertalk at 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 at arrl.net>,    <towertalk at contesting.com>Subject:    Re: [TowerTalk] Stacking question - another reality data pointFrom:    "Tim Duffy" <k3lr at k3lr.com>Reply-to:    k3lr at 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 K3LR - 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 K3LR______________________________________________________________________________________________TowerTalk mailing listTowerTalk at contesting.comhttp://lists.contesting.com/mailman/listinfo/towertalk ______________________________________________________________________________________________TowerTalk mailing listTowerTalk at contesting.comhttp://lists.contesting.com/mailman/listinfo/towertalk