Jim Mandaville wrote:
I am working over a Navy RBM receiver (the HF version) that I got at a
swap meet some years ago. It has zero value as a collector's item as
some previous owner (perhaps even the U.S. Gov.) was nice enough to
remove all the nameplates except the list of patents! I have the manual
for the "RBM, RBM1, RBM2 and RBM3" and this has all the necessary
diagrams, part lists and alignment info. It does not, however, give any
indication of how the different versions (1, 2, 3 and higher) differed.
Can anyone give me a brief overview on this question? My version, if
this is worth anything, has the big letters on the dials ("T" for tune,
"B" for band, etc. I'm trying to figure out what version this is ....

Jim, Do you subscribe to Electric Radio magazine? There's an article
in a back issue that I did a few years ago that describes the various
RBM and RBS variants. I'll try and locate my original manuscripts
and/or scan the pages. It may help you do an ident. BTW, does the
receiver have large lettering on 4 knob faces on the front panel? If
so, its an RBS, vice an RBM.

de Jeep/K3HVG