[Milsurplus] RBA, RBB and RBC

[Kenneth G. Gordon]

On 2 Sep 2015 at 0:00, Mike Morrow wrote:

> Mike wrote:
> If I had enough space, I would love to have the following heavy-metal USN
> receiver sets:
> 
> 1.  RAK, RAL

I have several of each of those: only one power supply though...all need 
refurbishment.

> 2.  RBA, RBB, RBC

Sigh...yes. I DO have a pair of RBAs with no power supply.

> 3.  AN/SRR-11, -12, -13A

I have only one SRR-12, but several of the SRR-11, 11A, 13, and 13A. All 
needing refurbishment. I'm keeping the -12. All but one of the rest can go 
sometime.

BTW, many years ago, a fellow I was working with who was doing VLF 
propagation research, bought a bunch of SRR receivers. The first thing I 
noticed was how HOT those things got! After some investigation, I found that 
the designers had connected the screens of all the submini tubes directly to 
the plate supply. By opening each module and adding a 56 K screen 
dropping resistor and appropriate bypassing, the heat level dropped 
dramatically. The reduced screen voltage did not appear to bother the 
receiver at all.

He ran them 24/7/365. He also used, mainly, RAKs, with recorders attached 
to monitor signal levels of the Navy VLF stations. There were a lot of them 
then. I really miss them.

> I'd want sets 1 and 2 especially.

Me too.

>  But of the eight receivers above, the only
> one I have is the AN/SRR-13A that I got from Navy MARS 46 years ago.  
> 
> I do have what is likely the best of the USN all-tube VLF/LF/MF receivers...the
> AN/WRR-3B.

Yes. Agreed. Very large.

> It's regretable how little there is to listen to below 30 MHz today, with no
> merchant marine Morse traffic nor even respectable shortwave broadcasting any
> longer.  I miss the 410 to 535 kHz MF merchant marine Morse band most of all.

Yes. Me too. That is why, something like 15 years ago, I and a bunch of 
other folks went to work to get experimental licenses to operate in the old 
600 meter band. I started a group named the "600 Meter Research Group" 
and applied for a license with about 30 of us on it. It was issued, but then 
when the first of our members got on the air, the USCG, which had been 
missed in the process, complained, and our license was withdrawn.

Then, a few years ago, a fellow out east somewhere, Fritz Rabb, a ham and 
EE, began a slightly different process, which, ultimately, resulted in a "new" 
630 meter ham band via the WARC folks...which the FCC has not yet seen 
fit to release for general ham use here in the U.S.

Even so, the FCC keeps issuing "Experimental" licenses for that band to 
many individuals. I am #24 on the license WD2XSH, some few details for 
which are on QRZ.com. There are quite a number of active stations on that 
band now.

Members have made contact with one another, literally, all over the world. 
New Zealand, Europe, Hawaii, Japan, etc.

It is a very interesting and useful band.

Ken W7EKB