[ARC5] ARA, SCR-274-N, AN/ARC-5 Remote Control Box Dials - Questions

[Mike Hanz]

> A possibility that occurs to me is that the numbers marked on the rear of
> the dials might be the ARC part or drawing numbers of the dial disks alone.
> The disk assembly, which is what the numbers in the manuals refer to, are
> three-piece assemblies (disk, thumbscrew, and keeper).

Well, yes - that is obvious in the center pair of dials in the photo I 
posted, which have both the disk drawing number and assembly part 
number.  Looking over the Record Parts List of Drawings Sent to Army 
(9/30/41) on Order 1470-NY-1941 and zeroing in on the BC-453 dial in the 
photo (the BC-946 not having entered the chain at that early date), 
Drawing Number 5614-2-E is listed as a subassembly of 6051, which is the 
whole dial.  The -2 represents the drawing size, and the -E represents 
the release number.  Clearly ARC was tracking details like that, even if 
the logistics chain wasn't so much.  Since the drawing size isn't 
particularly important, it appears they only recorded the release number 
and drawing number on the back of the dial.

An interesting if cryptic listing for the receivers is a 5301-1-D "Dial, 
Blank" that can be part of either 6051, 6053, or 6054 assemblies, and a 
"Calibration Chart" that is unique to each receiver.  I don't believe 
I've ever seen either of these in the flesh, unless you count the little 
tuner on a radar whose number escapes me at the moment, or the AN/ARQ-8 
control head, which may have used it as a basis for their special scales.

And I can almost hear Marty Reynolds grumbling about the long discussion 
on how many angels can dance on the head of a pin in one of these 
drawings...:-)

73,
Mike