[ARC5] Type-K based equipment dials

[Mike Morrow]

Michael wrote:

>Thus far, I know of phenolic receiver dials (as opposed to control box
>dials) on receivers made in 1943 by Colonial.  Were there others?

I don't know the answer to that.  All the receivers I've ever come across
use metalic dials, including the Colonial BC-946-B that's sitting here next
to me.  I've seen phenolic dials only on transmitters made by Colonial.

>Also, on the control box dials, some are luminous and some aren't.
>Who used what when?

That's an interesting question that touches on one that I've asked before.

The only luminous control box dials that I've seen are those for the AN/ARC-5,
known officially (but unmarked) as ID-24 through -28/ARC-5 for the R-23 though
-27/ARC-5.

Compared to the SCR-274-N control box dials (MC-212, -213, -214, -415 for
the BC-453, -454, -455, -946), the angled surface upon which the frequency
is painted has about three times the surface area.  This allows these luminous
dials to have numerals that are more than twice as large and bold as those on
the SCR-274-N versions, and presents those numerals more directly to the view
of the operator.  (One wonders why all such dials weren't made in such a manner
from the beginning.)

I have a question about the ARA control box dials, upon which the SCR-274-N dials
were modeled.  I have never personally seen an actual ARA control box dial, except
in ebay auction pictures on the associated control boxes.  ALL pictures of an
ARA control box with dials had the AN/ARC-5 type of dial installed...NOT the
expected ARA/SCR-274-N type of dial.

So, has anyone on the list seen ARA control boxes with the early type dials?
It would almost seem from the photgraphic evidence that once the improved
AN/ARC-5 dials were available, they were installed on the in-service or replacement
ARA boxes.

I am also interested in seeing a picture of a .52 to 1.5 MC receiver control box dial
*other than* the ID-25/ARC-5, which I have.  I have for years sought a MC-415
dial for my SCR-274-N with AN/ARR-1 set.  I've been told by some that they have
seen them.  But I'm left wondering if perhaps the dial they saw was actually the
more common ID-25 instead of the MC-415.

I've owned two NIB BC-946-B receivers.  They came from the box (almost) ready
for use with the AN/ARR-1, with the FT-310-A power adapter and the manual
supplement (but no DM-32-A dynamotor, of course).  The unique MC-415 control box
dial was NOT included.  That makes me wonder if the MC-415 exists.  It would
have been logical to have included it with the receiver, at least in the packing box
if not affixed to the receiver tube cover like on the AN/ARC-5.

My dash-1 manual for the B-29A says that its AN/ARR-1 worked through the AN/ARN-7
ADF, so maybe the classic expected combo of the BC-946-B and R-1/ARR-1 was seldom
(or never) utilized.  Still, one would think that all those many BC-946-B units out there
should have had at least one MC-415 made for them.

Mike / KK5F