[Milsurplus] HF SigInt, airborne platform

[Hue Miller]

I suppose the penultimate versions of GO were built in rather smaller 
numbers
than the GP, which I know for a fact was used in a greater variety of 
aircraft
than series GO.  I wonder also about military surplus disposal methods of
the interwar period; I suspect much of the procedure was simply to use the
things as learning tools for radio schools; as take-aparts.  I base that on
lack of mention or ads for mil-surplus for most of the interwar period,
at least, that I have seen, and the story of a local fellow telling me about
taking apart TCH's in his Navy radio classes. ( Even while the same radio
later used in North Africa by Brits - photographic proof in a number of
Radio News magazine . ) Thus, *maybe*, the non-existence of examples
of GO's pre suffix -9.

I still fail to understand how an airborne HF SigInt platrform offers
advantages over land-based stations.  Was this to get closer to
low powered transmitters? And in which theater of war? Many
of Japan's fighter planes used low power HF radios, in the power
range of 10 watts *input* power, but apparently many flew without
*any* radio, and later on, maybe around '43 on, low VHF began
to predominate anyway. ( Ditto for Germany. )
Was the ARR-7 a big success, a big contributor to Allied victory?
Or, barely used?
-Hue