[Milsurplus] GF and RU Relationships (Updated 03-22-08)

[Mike Morrow]

>I can add a little to this list.

Thanks, Robert, for filling in a significant number of gaps in the table.  The table is now 83 percent complete.  I have copied the table with your inputs below, and corrected of a couple of typos I had made.

>First, the frequency ranges shown in the various RU and GF/RU manuals is 
>purely administrative, not design.

What is interesting to ponder is why specific tuning ranges were ordered.

>Second, aside from being made by WECo instead of ARC, the RU-18 and -19 
>receivers are the same as later production RU-11 and -12.  RU-11 (S/N 1-300)
>and RU-12 (S/N 1-250) used 46048C.  Higher numbers and all RU-18 and -19 
>use 46048D.  RU-5 uses 46048A.  I don't have anything detailing when 46048
>went to 46048A or which RU models used 46048B.  The receivers used with GF
>are all 46051 or 46051A, at least from RU-4A on.

I also suspect, without having the manuals to prove it, that the difference between the RU-4 and -4A, and the RU-5 and -5A, is the location of the bias resistor.  (The A models were used with a GF.)  But that's just a guess.

Updated/corrected RU/GF Table:

   Transmitter                  Receiver               Contract
Unit  Frequency (KC)       Unit  Frequency (KC)  Volts   Date    Mfr+
 
--    --                   RU                      12            CBY
--    --                   RU-1                    12            CBY
GF                         RU-2                    12            CBY
--    --                   RU-2A 200-400           12  03-31-37  CBY
GF-1  6200-7700            RU-3  224-13575         12  02-10-34  CBY
GF-2                       RU-3A                   12            CBY
--    --                   RU-4                    12            CBY
GF-3  3000-4525, 6000-9050 RU-4A 224-13575         12  06-29-35  CBY
--    --                   RU-5  195-13575         12  05-16-36  CBY
GF-4                       RU-5A                   12            CBY
--    --                   RU-6                    12            CBY
GF-5                       RU-7                    12            CBY
GF-6  2000-4525            RU-8  200-400, 530-5600 12  02-23-38  CBY
GF-7  2000-9050            RU-9  200-400, 530-9050 12  10-31-38  CBY
--    --                   RU-10                   12            CBY
--    --                   RU-11 195-13575         12  11-22-39  CBY
--    --                   RU-12 195-13575         24  11-22-39  CBY
GF-8                       RU-13                   12            CBY
GF-9                       RU-14                   24            CBY
GF-10 3000-9050            RU-15 200-395, 530-9050 12  12-21-39  CBY
GF-11 2000-9050*           RU-16 195-13575         12  04-21-41  CW
GF-12 2000-9050*           RU-17 195-13575         24  04-21-41  CW
--    --                   RU-18 195-13575         12  04-21-41  CW
--    --                   RU-19 195-13575         24  04-21-41  CW
 
+ Manufacturer:  CBY = Aircraft Radio Corp.  CW = Western Electric Co.
* Early issue GF-11/12 frequency range was 3000-4525 and 6000-9050 KC.

I wonder what transmitter was to be paired with the early RU and RU-1.  Presuming these to date from 1932, that would seem to be before the the appearance of the GO- and GP-series that served with the later RU-series.

Note that odd RU-2A from 1937.  I have the manual for this.  It's a beacon-band only set dated about five years after the RU-2.

Additions to fill any of the 28 remaining gaps in the above table of 168 entries, plus any corrections, will be gratefully accepted and posted with acknowledgement!

Thanks.

Mike / KK5F