[Milsurplus] USN Transmitters on 500 to 1500 kHz (arc5 at ix.netcom.com)

[Hue Miller]

I also await with high interest any evidence for this.
You all know I have cited here several incidents of LF being transmitted by
search or scout aircraft, for other aircraft to home on. Or for ground 
stations
to give a position report on.
On the other hand, I have not cited, but have read, numerous incidents
where aircraft, yes even Navy or USCG aircraft, were unable to communicate
by radio with ship both civilian and foreign, commercial and military, and
instead used the light gun.
I came across some reading recently that talked about the use of LF
frequencies for air-ground communications in the U.K., even into the postwar
years. Perhaps I can locate this again, it might be a worthwhile tidbit to 
this
discussion. This may have been in the now defunct publication "Morsum
Magnificat". -Hue Miller