[TowerTalk] Bearings in Rotators

[Brad Pioveson]

The depressions that are all too commonly seen in the bearing races of 
Hy-Gain and CDE rotators are not - in the absence of some catastrophic 
event, such as dropping the rotor from the top of an 80' tower - the result 
of vertical weight loading.  They are, in fact, cratering - the erosion of 
the aluminum race.  This, apparently, is the result of a chemical reaction 
between corroded...rusted...steel bearings and the aluminum in the races. 
I'm no chemist (although I know one that I really should ask about the exact 
nature of the reaction), but, in every case where I've found damaged races, 
I've found rusted 3/8" dia steel ball bearings.  Where water has intruded 
into the units (rotors left in inverted positions or horizontally oriented 
while exposed to rain, for example), this effect will definitely be 
apparent.  Additionally, the effect will be more dramatic (deeper craters), 
and, the reaction take place must faster when you throw some salt, as in sea 
salt, into the mix.  Rotors that come into our shop for repair from coastal 
areas and KH6 have been prime examples of this.

73, Brad, W9FX
www.fxrotorworks.com