[R-390] R390(A) Gear Chemistry Questions

[Glenn Scott]

Questions for the group,


There are a number of gears in the mechassembly of the R390 series receivers that are brass colored.  I'veheard these called bronze and/or brass for decades. Does anyonereally know the actual chemistry involved in the manufacturing of thealloys used in those gears. 
Passing a strong Neodymium magnetacross the surface, you can feel a slight attraction as you'd expectfrom a high grade of near pure silver, however, the attraction doesnot pull the magnet to the gear. 
Is this due to a small iron content inthe alloy or does brass and bronze exhibit the same characteristicsas near pure Ag?
In my experience brass would be toosoft for use in those gears without there being other metals in thealloy;  I am NOT sure about the characteristics of Bronze.
These are very hard gears and have heldup very well in most of the R390 series receives I have restoredduring the last 20 years.  I'm just curious if anyone can confirm theprovenance of these gears?


Regards,


Glenn Scott WA4AOS 
DSM Labs
864 684 2956