[TMC] Wanted: Schematic on a modified FFR-2 (R-5007/FRR-502)

[WA5CAB at cs.com]

Roy,

First, with all due respect to Larry, although it's possible TMC might have 
built R-5007's with transformers having 100/200 VAC primaries, I seriously 
doubt it.  In October, 1944, TM 11-487 shows three places on the planet using 
either 100 or 100/200 VAC, Cairo (at 40 CPS), part of Thailand, and Japan.  Cairo 
converted to 220 VAC at 50 CPS, I've no idea what happened in Thailand, and we 
destroyed the Japanese infrastructure and then rebuilt it at our expense to 
120/208 60 CPS.  So I don't know who TMC might have built such a receiver for.  
All of the FFR-2 and R-5007 information in the three manuals I have says 
110/220 60 CPS.  My guess is that he had a shorted primary.

Second, production tube changes in the FFR and AN/FRR-49(V) RF plug-ins are 
documented in Temporary Changes to NAVSHIPS 0967-114-2010, which I said earlier 
that I have.  6BA6's replaced some of the 6AG5's and 6AK5's.  But there is no 
mention either in the manuals or in what you posted about the changes I asked 
about.

Third, AN/FRR-49(V) is the US military nomenclature assigned to the TMC Model 
FFR (specifically the FFR-2).  The (V) means variable configuration.  You 
could order it with whichever RF plugins you needed.  AN/FRR-502 is a Canadian 
nomenclatured set containing a fixed or specific mix of plug-ins.  

Finally, it would appear that the Canadian military nomenclature was assigned 
before the US as the receiver mainframe (R-5007/FRR-502) and all of the 
plug-ins carry Canadian nomenclature.  Which was not changed when the US bought 
some as AN/FRR-49.

And I'm still looking for anyone with information on an R-5007 mainframe 
modified with a 6BE6 in place of the 6AL5 2nd Detector/AVC.

Oh, and don't confuse "FFR" and "FRR".  "FFR" is TMC nomenclature for Fixed 
Frequency Receiver, meaning that the operating frequency was fixed (not 
intended for rapid tuning, anyway).  "FRR" is from the AN system, where the "F" for 
"Fixed" means that the equipment was intended for use in a fixed (non-moving) 
location.  As opposed to Portable, Vehicular, Ground, Transportable, Aircraft, 
Shipboard, "B" (Submarine) or "W" (either Surface vessel or Submarine).

Robert Downs - Houston
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MVPA 9480
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