[Milsurplus] [ARC5] SCR-A*-183 Broadcast Band Coil Set Listing

Tue Mar 16 09:47:53 EDT 2021

Interesting factoids about Doolittle and the SCR-183/283 radios.  Remember, Doolittle had a long term relationship with Aircraft Radio Corp. (ARC) and Radio Frequency Labs (RFL) in Boonton, NJ.  He had a personal office there.   ARC and RFL created the progenitors of the SCR-283 with the RU/GR series and before that the Model B receiver that Doolittle used in his “Blind Landing” experiment in 1929.  These TRF radios survived longer than perhaps they should have and “get no respect” compared to the ARC-5 series, also created by ARC.  A good history can be found in Radio Age of May 2016.

Ray Chase

From: arc5-bounces at mailman.qth.net <arc5-bounces at mailman.qth.net> On Behalf Of David Stinson
Sent: Tuesday, March 16, 2021 8:36 AM
To: Mike Morrow <kk5f at arrl.net>; arc5 at mailman.qth.net; milsurplus at mailman.qth.net
Subject: Re: [ARC5] SCR-A*-183 Broadcast Band Coil Set Listing

On 3/15/2021 3:56 PM, Mike Morrow wrote:

FWIW, SCR-A*-183/-283 RECEIVERS were designed to serve in liaison service with a complete range of receiver coil sets, or command service with a limited selection of receiver coil sets.  Even the last models from 1942 had a full set of receiver coil  set designations, so there were potentially "on paper" quite a few SCR-A*-183/-283 receiver coil sets that covered parts of the 540-1500 kHz AM broadcast band:

You are correct, of course, Mike.
 I have most of those
early manuals but didn't think of them.
I was using references like TM11-200 
and the models likely to be issued in 
1942 or later.
By then, the BC-229 was long gone from 
Liaison service, but that's no excuse for 
hasty writing.  I thought the modded 
RU coils for BCB were interesting
and hoped to generate some discussion.
If wearing a bit of "egg on my face" 
will do that, it's a fair trade :-D ;-)

If anyone has one of these Army BCB coils,
I'd be interested in some pictures.  I've been
collecting SCR-183 for a long time and have 
handled many Army receiver coils and have
yet to see a Signal Corps receiver coil which
covers any part of the BCB. 

My interest in the question was sparked by 
General Doolittle's telegram to the Kearny,
N.J. Western Electric plant, complimenting
the workers who were building SCR-183/-283
at the time.  The SCR-AR-283 tags are stamped
"Kearny  New Jersey." 

In that telegram, Doolittle stated:
"Through these radios, we issued commands 
between
ships that sent our bombers on their marks"*
and "... through these radios, we cheered each
other on," about as clear a description of 
Command Set usage as one could wish-for.*

He also stated:
"...through these radios, we heard the hysterical 
Japanese broadcasters, too excited to lie, 
screaming about the damage we had done."*
     * Target Tokyo, James M. Scott 
      W.W Norton & Co 2016 pg 372
      ISBN 978-0-393-35227-6 pbk

That's an interesting statement.  The Kearny-built
SCR-AR-283 manual defines receiver coils 
covering 200-400 KC and 2500-7800 KC, 
but nothing for the BCB.  Was he perhaps
confusing Command audio with Liaison audio?
Well, we can't know for certain- any extant manifest
of the equipping of the Doolittle B-25s is likely
buried in a dusty archive and will be there, 
unseen, until Judgment Day.  All the raiders
are gone now.  But we can make 
"educated guesses" with what we know.  

Take-off weight was critical.
The only aircraft that might have needed a Liaison
set would have been the lead, to report on the
mission.  All would need Command Sets and the
lower power and lower weight of the SCR-283
would make it ideal for a long range, "stealth" 
mission.  Moreover- If the one Liaison set was
SCR-287, its BCB coverage was limited to 1.5 MC 
and up.   A listing of Japanese AM broadcasters
at the time shows none operating above 
about 1100 KC,
possibly because there are veteran reports
of naval operations on those frequencies.

http://www.radioheritage.net/Story176.asp

The DF set at the Navigator's post would 
cover the BCB, but as far as I know, that 
audio is not piped to the Intercom system.

So was Doolittle, sending "buck-up" telegrams
to civilian workers after returning home,
using a bit of "license" to help the bond
sales and morale along, or did someone
dig-up some old Army BCB receiver coils
(and why would they?  Extra weight)?
As with so much of our passion, we
will never have a settled answer.
But it's interesting to think and discuss.

SCR-183/283 (and GF/RU) really 
should get more respect; it was in
service in suitable roles all through 
the war.  Even as late
as Dec of 1944, the AAC order 600
more of them be built, which was
probably the Philco -AS order. 
I use my set to check into local AM
nets when conditions permit QRP.
A little regenerative feedback sharpens
and enhances the receiver in crowded
conditions.  If you're careful and patient,
you can "slice away" those Side-Bandits
and enjoy some nice audio.

GL ES 73 OM DE Dave AB5S

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