Even More Planning Issues For Tower Collocation

How Much AM Power is Too Much?carrier perspective is convenience for fast and safe
As power on a tower goes up, potential carriermaintenance and/or system modifications. This
collocation issues increase. The feasibility of towersuggests the choice of a tower that is inactive in one
collocation is a matter of budget and operationalmode (preferably daytime) and that uses low power.
convenience for both the AM and carrier. The choiceAt the same time, that tower should be low
of carrier isolation technology is an important factor inimpedance and stable for minimum perturbation of
the analysis. In a directional array, the important factorarray operation. Part of the equation is accessibility for
is the power in the tower under consideration, not theroads and underground utilities without unreasonable
licensed power. A thorough engineering investigation isdisruption of AM transmission line and ground system
necessary in all but the lowest power situations.elements.
Successful collocates can be done on 10,000 wattFor the protection of both the AM and the carrier, it is
towers, but usually "lower is better"!very important that coordination of RF grounding,
AM Directional Compatibilityequipment placement, interim operation and RF safety
Collocation on one or more towers of a directionalplans be accomplished and memorialized before
array is often quite practical. In fact, in terms ofconstruction begins.
maintenance flexibility, such installations can offerConstruction will inevitably result in some AM array
advantages over nondirectional tower collocations. Adisruption, and plans should be in place for appropriate
good directional array collocation requires a balanceFAA notices, FCC STA's, power reduction, pattern
between carrier operational logistics and AM technicalchanges, or other actions to facilitate the construction
factors.phase. Of course, associated costs should be factored
The number one factor in tower selection from ainto the lease agreement.