[Milsurplus] ATC-*, TCZ-*, and AN/ART-13* Time Lines

[Mike Morrow]

Robert wrote:

> As I said earlier, AN/ART-13 was created by simply changing the nameplates
> on the various ATC conponents. Cxx-52286-A became T-47/ART-13, etc.

Todd wrote:

> ...thought you meant that TCZ was re-tagged as ATC or vice versa.
> Looks like it was Mike M who mentioned this.

No, I've never said anything that differs significantly from what Robert
states with respect to many ATC-* components being transformed into
AN/ART-13 components by simply being re-labeled...including sometimes
by only a crude yellow paint stencil with the JAN nomenclature near where
the original ATC-* nomenclature plate remained.

What I did write recently in this thread was:

> Even the early T-47/ART-13 (not sure if they were just re-labeled ATCs
> or newly-made T-47s) used that old GP-*/ATD type mount.  It had a JAN
> nomenclature of MT-161/ART-13 for the stationary rail part.  They were 
> apparently almost all replaced by the MT-283/ART-13 attached to the
> transmitter and the MT-284/ART-13 stationary shock base.

So...nothing there from Robert or me about ATCs becoming TCZs or vice versa.

I do think, when speaking of the re-labeled ATCs becoming T-47/ART-13s,
that it is important to not read that as saying all T-47/ART-13s were
originally ATCs.  I suspect that only a small percentage were, with most
T-47/ART-13s having been manufacured as that at time of manufacture.

The contract date for the first ATCs was 20 May 1940.  AFAIK, the contract
date for the first TCZs was 9 May 1942.  None of those dates indicate when
ATC or TCZ units were actually in service.  Late 1943 or early 1944 seems
more likely to me.  I'd be grateful if those more knowledgeable would correct
this (or anything else I post) if it is wrong.  
  
> Having been exposed initially to only the ART-13 versions (probably through
> its larger numbers) and their replacing the BC-375 later in the war, I'd
> always thought the radio proper was a later arrival. Hence the surprise
> that it was already being used in the first few months of the war.

The ATC and TCZ were not in service that early.  The TCZ contract date of
9 May 1942 is just that...a *contract* date, not an *in-service* date.

> I've known for some time that the Navy also employed this transmitter...

Here is a sketchy list that represents my understanding of the
time lines for these related equipments.  Anyone who knows something
different please provide additions and corrections!

The USN was the service that initiated Collins ATC development, the same
time that they awarded Bendix a competing contract for the ATD.  The
initial contracts were *both* awarded 20 May 1940.  

1.  ATC - SHIPS 242A (from 01/1945) shows the ATC as dating from 1942, and
    the ATD from 1940.  SHIPS 242A normally shows *contract* year, so their
    ATC year should say 1940, just like the ATD entry.  I believe, from
    issue dates of various instruction manuals, that the first in-service
    dates took place in early 1943.  The ATC-1 is the ATC as built by
    Zenith.  SHIPS 242A states that its year was 1942.  I would like to
    hear from anyone who knows the ATC-1 contract date.
2.  TCZ - The initial contract date is 9 May 1942.  It's most likely also
    saw 1943 as its in-service year.  The TCZ-1 is shown to be same as the
    TCZ except for MG-Rectifier unit changes.  The TCZ-2 is not listed in
    the SHIPS 242A of 01/1945, but it is covered in the 1946 TCZ-* instruction
    book.  All three versions were made by Collins.
3.  AN/ART-13 -  SHIPS-242A shows the USN AN/ART-13 (Collins, Zenith) year
    as "1943-1944", which could very likely be in-service dates for the ATC
    and ATC-1, followed re-naming ATC and ATC-1 to the AN/ART-13, followed
    by contracts to Collins for units built as the AN/ART-13.  I would like
    to hear of any new-built T-47/ART-13 units that were NOT made by Collins.
4.  AN/ART-13A - I believe USAAF AN/ART-13A sets appeared in late 1944,
    the earliest issue date of any manual I've seen which references the
    T-47A.  Stewart-Warner was the manufacturer.  I'd like to learn of any
    T-47A/ART-13 units that were NOT made by Stewart-Warner.
5.  AN/ART-13B - I have one manual that describes the early AN/ART-13B
    as a T-47A/ART-13 with CDA-T, apparently without any nomenclature
    plate change, and the later T-412/ART-13B as being the same as the
    early model, but with addition of the LF EXTENDED RANGE switch that
    adds a capacitor to a driver stage.  This allows MF/HF tuning to reach
    down to 1670 kHz (when the appropriate crystals are in place in the
    CDA-T).  All AN/ART-13B units were converted from existing supplies
    of T-47A, T-47, ATC, and ATC-1 units.  All that I've seen in manuals
    are built on the USAF T-47A.  Most that I've seen in real life or
    pictured in auctions are built on USN T-47, ATC, and ATC-1 units.
    I do not believe that this is a clear indication that the USN was a
    user of the T-412/ART-13B.  The standard USN AN/ARC-25 was a plain
    T-47/ART-13 and R-105*/ARR-15.  I believe that the T-412 dates from
    the early 1950s, based on its JAN component number.

NOTE:  The Collins commercial designation of the ATC or AN/ART-13 is
       the 17H-2.

> ...and also that they often tended to be the first to try new items
> due to available funding.

I don't know that the USN really deserves too much accolade *over* its
sister services.  The US Army had some really innovative gear such as:
1. The world's best aircraft ADF (SCR-269-*)
2. Good (for the time period) VHF command set gear (SCR-522-A, AN/ARC-3)
3. A capable liaison receiver.  The USN never developed a good equivalent
   to the simple BC-348-*, whose basic electrical design dated to 1936
   and was still flying in a few older USAF aircraft in the early 1970s.
   The RAX-1 is good, but it's bulky, requires more power, and doubtless
   was much more expensive in toto than the BC-348-*.  The BC-348-* (a.k.a
   AN/ARR-11) provided full coverage for the USAAF's AN/ART-13A in
   the AN/ARC-8.  Not even the excellent post-war AN/ARR-15 could do that
   for the AN/ART-13 in the USN AN/ARC-25.
4. The USAAF ILS (SCS-51, AN/ARN-5*, RC-103-A) was so good that 70 years
   later it's still the basis for current ILS worldwide.  The USN ZA and
   AN/ARN-9 "Air-Track" system was pathetic in comparison.
5. The US Army's SCR-300 and several mobile low-band VHF-FM tactical
   sets set the pattern for use that still exists today, while the USN
   was still trying to use TBW/RBM, TBY, TBX, MAB, and DAV gear for
   similar purposes.

The USN does deserve credit for its part initiating some great systems:
1.  ATC
2.  ZB/YE, YG
3.  TCS
4.  Early post-war aviation use of UHF-AM with the AN/ARC-12.

> Seeing this preliminary [TCZ] manual certainly added more texture to
> the overall feel.

I have a TCZ manual identical to yours except for serial number.  Mine
is 405-887.  Note that the front page says the LF/MF coverage is 300 to
600 kHz (just like the GO-* sets), but inside it is shown as 200 to 1500
kHz.  However, I have seen photos of a TCZ-* with a three-band LF/MF
oscillator unit (200 to 600 kHz) compared to the normal six-band 200 to
1500 kHz unit.

> Seems there's always something new to learn, regardless of how much we
> already know.

It's the history of the development and use of this equipment in the
military service that really interests me.  That information can be
destroyed, and much of it has been.

Someone smart and diligent and patient enough will always be around to
figure out how to put surviving gear on the air.  But the history of how
and why the gear came into being in the first place can easily be lost
forever...there will be no one capable of its recovery.  If it's ever
a choice between having just the gear or having just the documentation
I'll always take the latter.

73,
Mike / KK5F