[Milsurplus] More questions on AN/XXX.. more

[William Donzelli]

> I think there is little or no commonality.

Just in a very few weird cases, I think tools, pigeon stuff, photo
equipment and weather gear made the cross to JETDS with no changes.

> Notice the SCR system component ID letters are rather multi-purpose,
> compared to the JAN system.

It depends on the category. Certainly BC- is very broad, and can cover
anything from a rack of equipment to scopes to chests. Others are very
specific, like CP- for counterpoise or DM- for dynamotor.
 
There are a few catch-alls. EE- seems to be anything electrical that they
could not fit anywhere else, so "Electrical Equipment" makes sense. BD- is
a bit of a mystery (how did dynamotors get in there?).

> The equivalent in the old USN system identified the component function
> by the first two letters of the five-character designator (Cxx-aaxyz).  
> A few of the more common:
>
> 20, 21 - Power supply

Officially, class 21 is for rotating electric machinery, so plain old
motors and fans are there as well.

The class numbers missing from the lists did exist at one point, but they
are from the days of wireless. Things like Leyden jars, spark gaps, and so
forth. 

William Donzelli
aw288 at osfn.org