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
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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