[ARC5] Command set nomenclature ATA, ARA, AN/ARC-5 and so on ...

[WA5CAB at cs.com]

Les,

Pretty well.  What I didn't adequately explain was the difference between 
sets or systems, and components of those sets.  At the end of WW-II, there 
were three common electronic equipment nomenclature systems in use.  These 
were the Navy system, the Signal Corps or Army system and the JAN or Joint 
Army-Navy system (most commonly known as the "AN System).  The first two date 
from the WW-I time frame and the third from about 1942.  The third one 
replaced the first two although in most cases equipment identified under either of 
the first two remained identified that way.  There were a few cases where 
new sets were identified under either of the old systems and numerous cases 
where significant modifications either were or were not changed over to the 
new system.  And there were a few cases where the nomenclature was changed 
from old to new by simply changing nameplates on everything.

Anyway, all three systems have in common nomenclature that identifies an 
entire set or system and a different set of nomenclature that identifies each 
component (in this sense, "component" means a transmitter, control box, etc. 
and not a resistor, capacitor, or so forth).

In the Navy system, a radio set, sonar set, test equipment set, etc. was 
identified by a two letter nomenclature like RU, where "R" meant Receiver and 
U just meant either the 19th, 20th or 21st (sometimes the letters "I" or "O" 
were used and sometimes they were skipped) Receiving Set designated.  When 
the second letter got to "Z". the nomenclature rolled over to RAA, then 
about 26 sets later RBA  and so forth.  As I said yesterday, ARA and ATA were 
part of a brief subset of the Navy system.  Off the top of my head, I can't 
think of there being any non-aircraft examples.  

Just to take ARA, ATA and AN/ARC-5 as examples, each nomenclature means the 
complete system.  The full name of ARA is Aircraft Radio Receiving 
Equipment, and includes all receivers, racks, control boxes, connectors, etc.  Later 
versions of the same system would be ARA-1, ARA-2, etc.  Once in a while, 
you will see a nomenclature like ARA-2a, which never existed but would have 
meant some significant modification had been made, usually after production.  


The various components of ARA are identified by a 5-digit Navy Type Number. 
 The first two digits are "meaningful".  The remaining three begin with 
"000" and increment upwards potentially to "999".  The Navy Type Number for the 
BCB ARA receiver is 46103.  "46" means Radio Receiver.  "103" means the 
103rd radio receiver type number assigned.  The rule was that if a Type Number 
was assigned but not built, the number was not re-used.  The Type Number 
could be followed by an upper case letter beginning from "A", which meant a 
modification that was backward but not necessarily forward compatible.  Major 
changes got a new Type Number.  The Type Number on the nameplate was prefixed 
by a two, three, or four letter Navy Contractor Code, alway beginning with 
the letter "C".  The generic ID of the BCB receiver would be NT-46103. where 
"NT" meant Navy Type.  Generally, without the original nameplate it will 
not be possible to determine whether the receiver was built by A.R.C or by 
Stromberg-Carlson, or anyone else.  But CBY-46103 and CCT-46103 should be 
completely interchangable and usually identical. 
Navy Type Numbers were assigned to all system components but generally not 
to parts used to make the components (there are exceptions).  

With suitable changes to the system or radio set and components actual 
nomenclatures, all of the above also applies to the Signal Corps and AN or JAN 
systems.  For example, ARA and NT-46103 are the equivalent to SCR-274-N and 
BC-946-A, and to AN/ARC-5 and R-24/ARC-5.  Of course there are minor 
differences between the three receivers and the latter two system or set 
nomenclatures include the transmitters.  One could use ATA/ARA to get around the latter 
difference.

FWIW, the Signal Corps used a lot of Navy Contractor Codes on equipment 
nameplates, sometimes appearing as part of the Serial Number.

Robert D.

In a message dated 11/25/2013 04:22:55 AM Central Standard Time, 
vk2bcu at operamail.com writes: 
> Hi Robert,
>   Thank you.  It's always good to get a helpful correction.
>   However, looking at what you wrote below, and at the Wikipedia page
>   there is still some uncertainty in my mind.
> 
>   It seems that ATA/ARA  (as I see on the Wikipedia column heading)
>   applies to a complete CLASS of transmitters (first) and receivers
>   (ARA).
>   To repeat this idea, using transmitters as an example: according to
>   the Wikipedia page that individual items in the "ATA"  list include
>   the following transmitters:  CBY-52232,  CBY-52208 ... and so on.
>   So CBY-52232 is an example of one item that has the nomenclature ATA -
>   is that correct?
> 
>   Now to give the conflicting idea (which I NOW believe is wrong)
>   If I didn't have the Wikipedia page in front of me I'd conclude that
>   there was but a SINGLE item identified by ATA (not a set of
>   transmitters as I suggest above).
>   When some clever designer finished the SECOND transmitter was ATB.  So
>   one letter per item.  
>   It seems this understanding  is wrong (i.e. one letter of the alphabet
>   does not go with a SINGLE type of receiver)
> 
> What I DO understand NOW is that ATA does NOT mean "aircraft
> transmitting apparatus".  It means a specific CLASS (the first class) of
> transmitters.
> 
>   How am I doing?
> 
> 
>   73 de Les Smith
>   vk2bcu at operamail.com
> 
> 
> On Mon, Nov 25, 2013, at 15:07, WA5CAB at cs.com wrote:
> >Les,
> >
> >Not exactly.  The Navy briefly use a modification or subset of their two 
> >and three letter electronic equipment nomenclature system in use since
> >WW-I 
> >which started off with three letters instead of two.  AFAIK, it was only
> >ever 
> >applied to aircraft sets and only remained in use for two or three years 
> >before the Navy nomenclature system was mostly superceded by the JAN
> >system.
> >
> >The first letter identified the environment in which the equipment was 
> >used.  A = Aircraft.
> >
> >The second letter identified what the equipment did.  R = Receiver and T
> >= 
> >Transmitter.
> >
> >The third letter was the sequence number, A = first set, B = second set, 
> >etc. 
> >
> >FWIW, under the original system, set nomenclature of ground and shipboard 
> 
> >transmitters began with "T" and aircraft transmitters began with "G".
> >
> >In the first two designated sets, ATA went with ARA and ATB went with
> >ARB.  
> >But ATC has nothing in common with ARC and ATD has nothing in common with 
> 
> >ARD.  ATE/ARE through ATK/ARK were similar glide bomb transmitters and 
> >receivers, with each letter pair having a different operating frequency
> >band, and 
> >virtually never turn up.  It doesn't appear that many were built and
> >those 
> >that were must have been pretty quickly superceded by AN/APW-nn sets.
> >
> >ATA/ARA was redesigned and redesignated AN/ARC-5.  ATC was redesignated 
> >(with no or only minor changes) AN/ART-13.  ARC was replaced by ARC-1
> >which at 
> >the second redesign became AN/APR-1.  ATB/ARB, ARD and ATD were dead
> >ends, 
> >with all but ARD serving under their original nomenclature through the
> >end of 
> >the War.  ARD and ARD-1 were replaced by AN/APR-1.
> >
> >Robert D.
> >
> >In a message dated 11/24/2013 19:08:42 PM Central Standard Time, 
> >vk2bcu at operamail.com writes: 
> >>Hello Carl,
> >>   You may well be correct.
> >>   I rely on other sources - and here my source is Wikipedia.   See
> >>   http://en.wikipedia.org/wiki/AN/ARC-5
> >>   The items in the "command" series of equipment are shown in a table.
> >>    Three columns in the table list the particular "class" of 
> transmitter
> >>    or receiver.
> >>
> >>   These are given as ARA-ATA, SCR-274-N and AN/ARC-5.
> >>    This is what I understand.  The designations ARA and ATA are 
> acronyms
> >>    for "aircraft receiving apparatus" or "aircraft reception apparatus"
> >>    (as I understand, but I could be wrong).
> >>    This designation refers to an early system of nomenclature used (as 
> I
> >>    understand) by the US navy to identify a particular type of
> >>    equipment.
> >>
> >>    ATA is rather the same - transmitting apparatus.  In other words 
> this
> >>    represents a particular class of apparatus.  The transmitter itself
> >>    is "CCT-52232" and from this I understand a transmitter made by
> >>    Stromberg Carlson, operating between 2.1 and 3.0 MHz. 
> >>
> >>    Finally, I understand AN/ARC-5 is a later development of the
> >>    "command" equipment used jointly by both the US (army) Air-Force and
> >>    the Navy.
> >>    
> >>   But all this is only "my suppose".  There are people on this list who
> >>   know about the naming conventions.
> >>   You may well be correct.  I know nothing about Collins equipment.
> >>
> >>
> >>   73 de Les Smith
> >>   vk2bcu at operamail.com
> >>

Robert & Susan Downs - Houston
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