[ARC5] Re: ARC-5 data tags...

[David Stinson]

brianm@carsoncomm.net wrote:
> 
>  FWIW, I have two ARA 1.5-3 mc. receivers here, both under the same contract
> number (NOs-74912).  Serial # 941 has had the date surgically removed,
> whereas serial # 2651 has the date intact.  Incidently, the date is June 29,
> 1940.  Can anyone get closer with the serial numbers?

The first production run of ARA receivers,
built by Aircraft Radio Corp. on contract NOs-74912,
had the June 29, 1940 date.  
The following CBY runs on that contract do not have the date.
I have quite a few serial numbers for ARA contract NOs-74912 
in the database.  
No serial numbers above around 2800 have the date.
If anyone has a dated set with serial number above 2800
or vice-versa, please contact me.

The percentage of plates with dates defaced is actually small,
leading me to think this order to deface the dates
may have been "catch-as-catch-can" enforced.  
Or, it could be, as has been proposed, that dates were defaced
only at the time of install.  
If that's so, it's evident it wasn't done universally.
I'd bet most of the field people thought it a pretty dumb idea.
By the time Stromberg Carlson got contract 
number NOs-96736 for Feb of 1942, the dates had reappeared.
I've only found one NOs-96736 with the date defaced.
Perhaps that was done in a single location by someone
who remembered the old orders, but who can say now?

There are two other contract runs of ARA/ATA,
which I believe were built late as replacements.
The rare CBY-built NXsa-53321 units 
(built on AN/ARC-5 chassis)
have the contract number hand-stamped on the
plates in a field specifically for that, indicating
they were built beforehand and supplied "as needed"
under a supplemental contract.
More interesting is Stromberg's NXsa-20124 ARA run,
as this contract number is also the one 
for Stromberg's first run of AN/ARC-5.  
ATA/ARA sets on NXsa-20124 are uncommon.
These plates have a field for the date to be hand-stamped,
but all I have ever seen are blank.

Navy acceptance test dates show that later-run
CBY's on NOs-74912 and CCT's on NOs-96736 were 
built at the same time.  NOs-74912 carried over 
into production of AN/ARC-5, but NOs-96736 did not.
CCT's NXsa-20124 carried over.  The Navy acceptance tests
stamps for both ARA and ARC-5 versions of NXsa-20124
lack dates.  However, from what we know, we can 
deduce that Stromberg's run of NOs-96736 was smaller
than CBY's NOs-74912, after which they began
on NXsa-20124.  Both they and CBY seem to have
halted ARA/ATA soon afterward 
and switched over to AN/ARC-5, keeping the same contracts.  
Acceptance test dates on the CBY runs support this.

Any conclusions we draw at this time are largely
speculation, but with the Naval records destroyed,
that may be all we shall ever have.
And what of that?  "Facts" slip through our fingers like sand,
and what is gospel today is heresy tomorrow.
When primary sources are scarce,
history belongs to whomever believably writes it.
I suppose we must be happy with that.

73 DE Dave AB5S