[Milsurplus] Odd?..GF TU

[Hubert Miller]

The simplest answer is: for getting bearing from direction - finder stations, or at rarer events, such as the discovery of the Indianapolis survivors, to provide a
DF target for other aircraft. Yes, I know the GF output is not much. They didn't build many of these MF TUs, right ? 
I have looked for evidence that any non-belligerent countries in the WWII years used the MF BC band 550 - 1500 for airfield communications, but never found
any. This includes a pretty good deal of looking.
-Hue