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

[Mike Morrow]

Mike wrote:

>I went out and took a couple of photos of the ones I have, Mike, and 
>it's a mixed bag.  Attached are two photos of the dials, front and 
>back.  The rear view is simply the front view with each dial reversed in 
>position.  The one on the upper right is for the BC-453, and is yet 
>another type that is commonly encountered - made of black Bakelite 
>rather than aluminum.  You can see that the two right hand dials are 
>both marked C-****, while the rest are all D-****.  Whether that 
>signifies 274N or not, I do not know.

Thanks for taking the trouble to produce those photos, Mike.  I suppose
that the lower right .52 to 1.5 MC dial is the rare SCR-274-N MC-415 dial,
or much less likely, an original early-ARA #6052 dial.  It's the first
one I've ever seen.  I also have never come across a bakelite dial.

Those numbers like "D 5611" don't correlate to any part or drawing number
that I've ever seen, but the four digits are consistent for each dial type.
Here's the info stamped on the back of the dials I have, all of which are
aluminum.
                                                                   Dial
  STAMPS on Back of Dial     Manufacturer       Associated Set     Font 
                (0.19 to 0.55 MC, #6051/MC-212/ID-25) 
E 5614                     Stromberg-Carlson   Late-ARA, AN/ARC-5  Large
E 5614/ASSEM. 6051/A.R.C.  A.R.C.              Late-ARA, AN/ARC-5  Large
B-5614                     Western Electric    SCR-274-N           Small       

                (0.52 to 1.50 MC, #6052/MC-415/ID-26) 
D 5611                     Stromberg-Carlson   Late-ARA, AN/ARC-5  Large
D 5611/ASSEM. 6052/A.R.C.  A.R.C.              Late-ARA, AN/ARC-5  Large

                (1.50 to 3.00 MC, #7575/------/ID-27)
A 7326                     Stromberg-Carlson   Late-ARA, AN/ARC-5  Large
A 7326/ASSEM. 7575/A.R.C.  A.R.C.              Late-ARA, AN/ARC-5  Large

                (3.00 to 6.00 MC, #6053/MC-213/ID-28) 
B 5623                     Stromberg-Carlson   Late-ARA, AN/ARC-5  Large
B 5623/ASSEM. 6053/A.R.C.  A.R.C.              Late-ARA, AN/ARC-5  Large
B-5623                     Western Electric    SCR-274-N           Small

                (6.00 to 9.10 MC, #6054/MC-214/ID-29) 
B 5607                     Stromberg-Carlson   Late-ARA, AN/ARC-5  Large
B 5607/ASSEM. 6054/A.R.C.  A.R.C.              Late-ARA, AN/ARC-5  Large
B-5607                     Western Electric    SCR-274-N           Small

There doesn't seem to be a correlation that can be made to the letter
in front of the four-digit number stamped on back.  Even the small-font
dials of the SCR-274-N MC-213 and MC-214 have the same combination as
the large-font dials of the late-ARA and AN/ARC-5.

I'm still interested in hearing from anyone who has an early ARA control
box (like CBY-23251) that has the original small-font non-luminous dials
of the type that was continued throughout the history of the SCR-274-N.

The MC-415 is interesting.  I've had two NIB BC-946-B BCB receivers in
past 15 years, made by Colonial.  They both came out of the box with the
FT-310-A power adapter (for the associated AN/ARR-1) and a small instruction
book.  It was surprising to me that there was no MC-415 dial included for
the associated BC-450-A.  I wonder where the technicians got one for those
rare USAAF uses of the AN/ARR-1 with the SCR-274-N.  I suppose they could
leave the dial for the displaced BC-453-B on the BC-450-A and mark it to show
the pilot where to find the modulating frequency of the YE/YG homing beacon
of interest.  But who knows.  I think most of the AN/ARR-1 sets that were
actually installed in USAAF service were like the B-29 installations
which used the AN/ARN-7 ADF set to process the output of the AN/ARR-1.

Mike / KK5F