[LMB] OT: Tech marches on
lmb at matija.com
Tue Dec 14 12:02:03 GMT 2021
On 14/12/2021 10:22, Raymond Collins wrote:
> ELF or extremely low frequency allows submarines to receive secure
> communications from the US deep underwater.
Yes, but only for sending to submarines, submarines have to surface to
> I'm uncertain how deep
> underwater the signals can be received but I know the the ELF antenna
> cables went underwater.
I don't think that's true. The radio very long radio waves penetrate
water, but the antennas are still in the air, not underwater.
> The communication rate was very slow.
With a base frequency of 24kHz (and probably a suitably narrow band), I
am not surprised. The wiki page I linked mentions that only coded
messages can be transmitted, not speech.
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