[Collins] R-388 second mixer weirdness

[Jim Brannigan]

This past year I've had problems with silver micas in a Ranger and a CV-591.
In both cases the silver micas were the last suspects.
Recently I've noticed a little "thunderstorm" noise in an otherwise very 
quiet R-390A.
When I get it on the workbench (oof!),  the interstage caps will be the 
first to go.

I am not a fan of shotgun replacement, but lately "if one is bad, they all 
go".

Jim

> Well this is proof that the micas can fail, but still not that they have
> such a high failure rate that they should be shotgunned. Likely this one
> would have changed from either prodding (with a fiber or orange wood
> stick) or temperature cycling with hot air and freeze-mist.
>
> -- 
> 73, Jerry, K0CQ, Technical Advisor to the CRA