Here are the two diodes I selected to replace the failed ones in my MEP-006A Military 60kW generator.
http://www.mouser.com/Search/ProductDetail.aspx?R=1N1190Avirtualkey66430000virtualkey905-1N1190A
http://www.mouser.com/Search/ProductDetail.aspx?R=1N1190ARvirtualkey66430000virtualkey905-1N1190AR
You would need x3 of each and I recommend getting a spare if you aren’t familiar with proper torque and are prone to breaking studs off components. One is a reverse connection of the other (designed 1NxxxxR)
Specifications:
Three of one type are on one side of the aluminium rectifier mount, and the other three are on the other side. Make sure you use plenty of thermal conduction grease when making the connection.
I also have 006A and exciter trouble, not the diodes but the voltage regulator circuit board – failed pulse transformer and associated diode and transistor. It was not regulating properly and I was attempting to troubleshoot and adjust the gain and stability – there was a bad solder joint at the large capacitor C201 i think which was causing the erratic voltage regulation. My probing caused a back feed and smoked the output winding of the pulse transformer… Have found a similar pulse transformer and possible transistor but all are obsolete and it might be better to find a used board – any ideas?
Did you ever fiqure out why the diodes failed on your unit? They seem pretty tough unless something failed in the windings…?