[ARC5] Re: A.R.C. Alternatives

[Mike Morrow]

Jack wrote:

> Just for arguments sake, what about the ATB/ARB set ?

I believe the ARB/ATB would have made a very servicable substitute,
although the ATB itself is not one of my favorite transmitters.  I
never figured out why they made the ARB and ATB in somewhat different
shape and size.  One would think that they could have been made in
identical cases, and perhaps used the same mounts.  ARB mounts are
pretty easy to find, but AFAIK, those for the ATB are almost
mythological.  The ATB (like the ATD and TA-12) has no direct frequency
indication, but since a command set would likely be set to frequency
by ground crew, that lack was likely not a problem.  

One nice thing about the ARB (and the ARA) command receivers is they
both accomodate the addition of the USN's vital ZB-series homing
adapter, requiring only the adapter and the power and RF cables.
No adapter control box or antenna relay box with associated plugs
and cables are required, as it is to use the ZB with the RU-series.
That feature of the ARB is described in an ARB document at Mike
Hanz's site (http://aafradio.org/docs/docs.html).  The ARB even has
mounting clips for the ZB.  (ZB-2 and -3 units usually go for the
price of dirt on ebay, so make your ARB happy by giving it one.
It'll make an interesting conversation piece!)

The ARB/ATB seems to have been available by 1942.  By 1942, Bendix
also had its RTA-1B ten-channel all-in-one-case HF receiver-transmitter
available.  It would have been handicapped by need of 20 quartz crystals
for its ten channels (among other things), but it was given military
JAN nomemclature and some service use as the AN/ARC-9.

Michael wrote:

>By mixing systems a bit, the RAX & TA-12 would make an interesting
>installation as well, though I can't remember if the RAX had remote
>bandswitching.  If not, that could prove a bit sticky.

That seems to me to be a strange combo.  The RAX-1 has no remote
control capability of any sort, and to cover the frequency range
of the RA-10 receiver which normally accompanied the TA-12, you'd
need at minimum the CG-46115 and CG-46116 units (and an operator
to control them).  That would take up significantly more space and
weight than the RA-10, yet still not provide any capability for
LF/MF RDF loop connection such as is possible with the RA-10DB.

I'm convinced that the RAX-1 would never have served satisfactorily
as a command set receiver, being at a significant disadvantage even
to the old RU-series as far as remote control capability.

>... Bendix (if no one else) was ready to step in with their own
>products.

They surely did have sets with that capability, such as the
RA-10DB/TA-12B combo.  The RA-10DB provides LF/MF reception and
RDF from 150 to 1100 kc, and MF/HF reception from 2000 to 10000 kc,
remoted controlled.  This provides significantly more receiver
coverage than the A.R.C. command set of three.  The TA-12B provides
four remote-select channels of operation in the following ranges:
300 to 600, 3000 to 4800, 4000 to 6400, and 4370 to 7000 kc.  The
A.R.C. command set requires three transmitters to cover the HF
span of the TA-12B, and provides no LF/MF capability.  (I'm ignoring
the rare and late T-15/ARC-5.)  The generous frequency overlap
between channels allows one TA-12B to be set with three channels
operating in the heavily utilized 4000 to 5000 kc range, while
the A.R.C. command set would require three identical 4000 to 5300 kc
transmitters in a three-unit rack.  The main disadvantage of the
RA-10/TA-12 compared to the A.R.C. command set is the inability 
(potentially important) of the receiver to monitor multiple 
frequencies simultaneously, and some lack of redundancy.
There is no size/weight advantage of the typical three-receiver,
two-transmitter A.R.C. command set, over the RA-10DB/TA-12B.

The RCAF Mosquito installation shown at:

http://www.jproc.ca/ve3fab/mosquito.html

employs the RA-10/TA-12 as the liason set, with none of its controls
available to the pilots.  The SCR-522 is the command set, with its
control available only to the pilot.

IMHO, the best WWII outputs from Bendix were the SCR-522 VHF command
set, the SCR-269 ADF, and the RA-10/TA-12 LF/MF/HF set.  These alone
would ovewhelm the very notable, but far narrower and modest, output
from the Aircraft Radio Corporation.

Mike / KK5F