[ARC5] RAT(-1) & RAV: Another Viewpoint.

[Mike Morrow]

Michael wrote:

>The GE-built GO-4, -5, and -6 came out in 1938 & 1939 but the RAX didn’t
>shine until 1940.  In the meantime, the Navy had these transmitters for
>which they had no accompanying receivers to match the full frequency
>coverage and apparently GE wasn’t in a position to deliver on time.

I don't know the evidence for GE not delivering something on time.  That
implies that there was some commitment to deliver something by a certain
date.  Is there evidence that GE was to have delivered the RAX (1940) with
the GO-4 (1938)?  If so, I think that its nomenclature would have been earlier
than the nomenclature assigned for the RAT and RAV, if in fact the RAT and RAV
came into existence because of delays with GE providing the RAX.

>ARC ... already had a positive relationship with the Navy
>(specifically BuAer) via the RU & GF equipment and really wanted to sell
>them a complete command system to replace the GF/RU based on the Type K
>design*.  Either the Navy went to ARC or vice versa but however it happened,
>ARC wound up providing *stop gap* equipment until the RAX was ready for
>prime time –fifty systems to extend the coverage beyond existing RU
>installations and fifty that were complete entities unto themselves –while
>proving the designs to the Navy’s satisfaction.

It's important to note that this is the case of A.R.C. providing *liaison*
receivers to extend receiver coverage beyond the 13.575 MHz limit of the
A.R.C. RU-* liaison receiver system to cover the 26.5 MHz limit of the
GE GO-4/5/6.  Thus, there came the 1939 RAT and RAT-1, with coverage
from 13.5 to 27.0 MHz.

I think we also agree that the 1940 RAV had entirely the same purpose as the
RU-* with RAT/RAT-1 system described above...which was *liaison* receiver
service, carried out using eight Type K derivatives including the two
CBY-46108 and CBY-46109 receivers that were also part of the RAT-1 system.
It's interesting that the CBY-46xxx numbers of the 1939 two-receiver RAT-1 
(46108 and 46109) were in proper sequence with the CBY-xxx numbers of the 1940
eight-receiver RAV (46102 through 46109).  Despite the contract date
differences, it seems that the RAT-1 and RAV were designed at the same time.

>* While the system had originally been designed with the AAC in mind,
>they didn’t have money.  The Navy did and those were pockets to pick to
>eventually get the ARA/ATA system out and visible in an operational
>environment.

And now A.R.C. finally gets orders for a *command* set based on the Type K!
But only three receivers (46104 through 46106) in the RAV system survive
unchanged to become ARA sets.  The two RAV navigation receivers (46102 and
46103) have their loop connections and switch eliminated (becoming 46129
and 46145) before joining the ARA lineup.

>In any event, I do not believe there was ever any intent or need to build
>more of either the RAT(-1) or RAV since the RAX finally became available
>although too late to perform its intended role of accompanying the GO-4, -5,
>and -6.

I agree, but the 1940 Westinghouse GO-7/8/9 transmitters upper limit was
18.1 MHz, so these last units of the GO-series would also require receive
coverage above that provided by the RU-* liaison receivers.

I suspect that most of the 46 RAT and 46 RAT-1 and 50 RAV systems found
themselves paired up with GO-4 through GO-9 liaison transmitters in long
range patrol aircraft well before the start of WWII.  One could reasonably
theorize that A.R.C. hoped that their 1940 RAV would be competitive with
GE's 1940 RAX for general liaison service, but it would not take long to
recognize superior design of the RAX over the RAV.  Based on staging
(two RF, three IF stages) and bandspread alone, the RAX CG-46117 receiver
must have easily outclassed the RAV CBY-46106 through -46109 receivers
(one RF, two IF stages) covering the same frequency range.

The A.R.C. star would shine only in the sky of the MF/HF command set.

>I don’t know the production quantities for the various models of the
>GO-series.

One wonders if such information survives anywhere.  I'd imagine that the
various GO transmitters such as the rare versions before GO-9 were
themselves not manufactured in quantities greater than the RAT and RAV.
There's a GO at the Naval Aviation Museum in Florida in a PBY cut-away
display.  It's identified as a GO-9, but it obviously isn't.  I believe
it is a GE GO-6.  I hope to get down there this summer to take a look.

>Best regards,
>
>Michael, WH7HG

Welcome back to the list.

Mike / KK5F