[Top] [All Lists]

Re: [TowerTalk] Stacking Tribanders

Subject: Re: [TowerTalk] Stacking Tribanders
From: Brian Beezley <>
Date: Wed, 22 Jun 2022 06:37:51 -0700
List-post: <>
Here's how TA handled stacking:

        ---- STACKED ANTENNAS ------------------------------------------

                TA can plot the pattern for a pair of antennas with
        vertical and/or horizontal offset. First snapshot the pattern
        with the antenna at one stacking location. Then move the
        antenna to the other location and press C. TA will plot the
        pattern for the two antennas excited with equal current
        magnitudes. Press B to toggle between BIP (both antennas in
        phase) and BOP (both out of phase). Press C to toggle between
        stacked and individual patterns. Vary antenna height with
        stacking enabled to find optimal stacking distance.

                TA assumes the isolated, free-space, antenna patterns
        aren't affected by mutual coupling between the antennas. This
        isn't quite true for most antennas at typical vertical stacking
        distances, but usually only the rear part of the pattern is
        affected in a minor way. However, interaction can be large when
        stacking horizontally if one antenna fires directly into
        another, even when the antennas are separated by some distance.
        Use AO or NEC/Wires to accurately determine gain and pattern
        degradation for stacked antennas over flat earth.

                TA uses pattern integration to establish array gain.
        This provides realistic gain, even for small stacking distances.
        However, TA needs the complete elevation pattern for accurate
        pattern integration. Therefore it doesn't allow restricted
        analysis range when stacking antennas. TA inhibits changes to
        certain other parameters while stacking to maintain the same
        modeling environment for both antennas.


TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>