[ARC5] RAL, RBA, RBC Manuals and info needed

[Ben Hall]

On 5/24/2016 5:42 PM, WA5CAB--- via ARC5 wrote:
> You need to say what the suffix numbers are following the RBA-, RBB-
> or RBC-. The statement in a previous post to the effect that all
> RBA's, RBB's and RBC's are the same is only half right.

So...I'm a bit of an RBA, RBB, and RBC nut.  I've got a bunch of manuals 
in my collection past the ones I've scanned and posted.  I see very few 
technical changes between the dash number revisions.

> One rule of thumb that does apply to the RBA, RBB and RBC is that the
> odd suffix number models are bench mount and the even ones rack mount
> (<BLANK> being an even number). Which is why each of the NAVSHIPS
> manuals except for the first one covers two model numbers, one bench
> and one rack.

I'm not sure this is always the case...

Contract NXss-17001 / Preliminary IB-38216-P1 - "Radio Receiving
Equipment Models RBB-2/RBC-2" notes:

"4.1  The receiver units of the Model RBB-2 and RBC-2 equipments are 
designed for mounting on the top of an operating table using the rubber 
shock absorber mountings supplied with the receiver unit cabinet (see 
Figures 38 and 39)."

Figures 38 and 39 show a table-mount cabinet, not a rack-mount unit.

NAVSHIPS 900,477 - "Instruction Book for Radio Recieving Equipments Navy
Models RBB/RBC, RBB-1/RBC-1, RBB-2/RBC-2"

Doesn't show a rack-mount unit nor describe a rack-mount unit in Section 
II - Installation, stating "a. General.  (1)  The receiver units of the 
Models RBB and RBC Radio Receiving Equipment are to be mount on top of 
an operating table using the rubber shock mountings (A105, A106, or 
A205, A206) supplied with the receiver unit cabinet."

NAVSHIPS 91101 - "Instruction Book for Radio Receiving Equipments Navy
Models RBB-3, RBB-4, RBC-3, and RBC-4"  (this manual has a ton of 
errata) notes...interestingly...

"a. General.  (1)  The receiver units of the Models RBB-3 and RBC-3 
Radio Receiving Equipments are to be mounted on top of an operating 
table..." noting the same thing as the -1 and -2 manual.  But 
note...doesn't mention the -4 configuration, even though the manual 
covers it.

Only when we get to NAVSHIPS 91469 - "Instruction Book for Radio 
Receiving Equipment Navy Models RBB-5, RBB-6, RBC-5, and RBC-6" is there 
note of a rack mount case:

"2.  Installation.  The RBB-5 and RBC-5 units are supplied with shock 
mounts attached and are intended for table-top installations.  The RBB-6 
and RBC-6 units, however, are not furnished with shock mounts but 
include mounting ears for rack mounting."

The parts list included both an NT #201130-B rack type power 
supply...and a cabinet type power supply.

My collection of errata includes:  "30 July 1951.  Temporary Correction 
T-1 to Instruction Book for Models RBB-5/6 and RBC-5/6 Radio Receiving 
Equipment" requests that page 8-1 be amended to include a rack mounting 
cabinet part number...page 8-2 have the rack cabinet added to the 
description, and then says to "Delete complete description Power Supply 
NT #20130-B (Rack Type)."

All of my RBA manuals are for odd dash variants:

NAVSHIPS 91559 - "Instruction Book for Radio Receiver Equipment Navy
Model RBA-7"

NAVSHIPS 900,708 - "Instruction Book for Navy Model RBA-5 Radio Receiver
Equipment"

So neither are really any help determining the rack mount versus 
table-top mount debate.

INTERESTINGLY, that RBA-5 manual may be historically significant, it has 
pencil changes to it such as:

Crossing out NAVSHIPS 900,708 and noting "new number needs to be applied
for", and has the -5 in RBA-5 marked out throughout the document.

Apparently, this was the draft for a later revision of the RBA series.

I do not see any pencil changes made to the parts list and/or
schematic, so there must not have been any technical changes between the
RBA-5 and whatever manual eventually came from this manual.

Interestingly...I've got an RBB-2 that's in a rack mount case.  Funny, 
it's a steel case, not aluminum.  However, the quality of the case is 
hit or miss, so I suspect this was made by someone special and isn't an 
official Navy rackmount case.

thanks much and 73,
ben, kd5byb