Hi Guys, On 40 I have a 4-square, NE wirebeam and an Inv. V all coming to the same stackmatch. Ordinarily I would simply switch between antennas, however this weekend is SS and no doubt I will be usi
Tnx to all who responded to my guy wire spacing question. I have wondered how important it is to stack similar antennas or if it does not matter at all. If I wish to stack 3 15 meter beams, how advan
Bob, It is very important that the antennas, feedline (electrical) lengths and alignment of the antennas in the vertical plane (for a vertical stack) be identical for a stack to perform optimally. To
Author: chapoton@smtp-gw.gdls.com (Henry G Chapoton)
Date: Wed, 22 Jul 1998 09:30:17 -0400
Bob: You want to use identical antennas as N3RR pointed out. Also, to insure equal currents, you want to use feedlines from the antenna to the common point (t/b/l switch, etc) that are equal AND a 1/
N4KG comments intersperced below: On Tue, 21 Jul 1998 18:15:07 -0700 "Robert L. Shohet" <kq2m@eci.com> writes: Let me answer your questions with a question. What would be the relative phase between s
Author: Guy Olinger, K2AV" <k2av@qsl.net (Guy Olinger, K2AV)
Date: Fri, 24 Jul 1998 00:18:37 -0400
However, the effects are more pronounced on the stack's ability to deeply cancel high angle reception. The effects can be easily modeled with EZNEC, which allows the phase, and feed power levels to
Sometime back, I posted an inquiry regarding having two dissimilar antennas on the same tower. In this case, I would have a 4 ele Steppir at 70' and a 3 ele Steppir at 35-40'. Initially, I figured th
Ed, First, you are correct that even if you didn't try to use the two antennas in a stack, you would definitely see a benefit in having two antennas at different heights in respective of vertical tak
Run HFTA. You will be amazed to see that the little one at 35 feet will be MUCH better to some areas of the world at times. Here on the east coast there are times when the 40 footer will be 8-10 db b
Ed, stacking these two antennas does not present insurmountable phasing issues. You could model it and see. It might have unexpected results because of element spacing, etc, but nothing the model wou
Be careful when using HFTA to model stacks. HFTA does not model antenna interaction. All rays are assumed to go outward from the antenna between 0 and 34 degrees elevation. No rays directed upward at
I have a 3el 15M Beam on top of my tower that is stacked with an 8 el 15M beam at 30 feet when pointed NE and a 5 el beam at 50 feet when pointed south. None of the booms are the same length. You nee
I need to correct a couple of statement I made about HFTA. I said HFTA always gives 3 dB gain for any antenna stacking distance. That is not correct. It gives 3 dB gain for very closely stacked anten
Just one added point - for tri-bander stacks, spacings of less than .5 wavelength on 20M are quite common because the spacing used is necessarily a compromise between three bands (or at least 2, thes
Also, gain is often not the main goal when stacking tribanders; the main goal is often to cover two directions at once. Mark, N5OT _______________________________________________ ___________________
This is true, of course, but an even more important advantage, IMO, is take-off angle diversity; simply by switching from both antennas to the bottom one, I often find that it will revitalize a Europ
goal is often to cover two directions at once. My limited experience with stacked antennas showed that as important as 2 directions was the fact the stack filled in the nulls in the pattern resulting