[ARC5] RAX Receiver Component Numbers (CG-46xxx) Info Request

[WA5CAB at cs.com]

The Signal Corps had some systems that the Navy didn't have the equivalent 
of.  Specifically the SCR-508, 608 and 808.  In those systems the receivers 
and transmitters were the same for both 12V and 24V vehicles and had no 
primary voltage (12/24) selector switch.  The tube heater series-parallel wiring 
for either voltage was accomplished with wiring in the dynamotor plugs.  So 
it was desirable to be able to tell which operating voltage the radio was 
set up for without having to open up the radio and check.  I once ruined a 
complete set of tubes in a BC-603 because someone had installed a DM-36 
dynamotor onto a DM-34 base and had not rewired the Jones plug accordingly.  That 
put 12 volts across all of the 6 volt tube heaters.  

There were no 14 volt components for the SCR-274N (or ARA) so until the 
DY-1/ARR-2X was built, there wasn't a plug-n-play 12 volt dynamotor around (the 
Navy interphone dynamotors that look like they would work don't actually).

I would guess that the dynamotor in the unit on eBay was the dynamotor out 
of a DM-34 .  And that if whoever did it had the radio working, they also 
rewired the heaters for 12 volts.

In a message dated 2/11/2011 2:52:33 PM Central Standard Time, 
aaf-radio-1 at aafradio.org writes: 
> I have never seen a Navy dynamotor with the same large  "in your face" 
> voltage label as the Signal Corps used on their twin voltage equipment, 
> Todd.  Navy techs are perhaps taught to read the numbers more carefully 
> than GIs? :-D   More seriously, it's a good idea, sorta like the doctor 
> marking which foot he needs to operate on in surgery, but the Navy 
> didn't seem to be so concerned about it, and even the Signal Corps 
> didn't apply it universally...none of the SCR-274N sets used the marking 
> convention.
> 
> I saw that particular RAX-1 and it seemed apparent to me that whoever 
> had done the conversion simply transplanted one of the DM-35 (or 
> similar) Signal Corps dynos onto the RAX dyno mount.  It's one that 
> employed the standardized small receiver dynamotor frame size used by a 
> bunch of sets, including the command receivers.  As a result of the 
> modification, I was a little surprised at its final price.
> 
> 73,
> Mike
> 
> On 2/11/2011 3:02 PM, Todd, KA1KAQ wrote:
> >On Fri, Feb 11, 2011 at 2:28 PM, Mike Morrow<kk5f at earthlink.net>  wrote:
> >>Fantastic!  Even the XRAX was 28 vdc.  All this conclusively 
> demonstrates
> >>there were no 12 vdc RAX-type receiver systems.  Mike, I'd seen your
> >>XRAX pages several years ago but I'd forgotten all about them.
> >FWIW, there was a RAX-* receiver on ebay sometime in the last 6
> >months-year with a 12v dynamotor. While the set was mildly modified,
> >the dynamotor looked to retain the same mounting plate as the 28V
> >version (2 snap slides with handles) and sported one of those large
> >12V metal tags on it. Was pretty clear in at least one of the shots.
> 

Robert & Susan Downs - Houston
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