[R-390] Mechanical Filter Failure?

[Robert Nickels]

Thanks for posting all those great links John.  I recently found a 
coil-to-case short in a FA type filter, but was able to clear it and the 
filter works again.  Still puzzled as to the cause, but these post 
mortems give a renewed appreciation for the engineering that went into 
the design of these filters.   All before the age of CAD, FEA, and Spice!

73, Bob W9RAN